Protocell redux

lucaspa · Mar 22, 2003

For anyone wanting to argue against protocells, like any scientific theory, you have to address the data.  So, to start off, here is some of the data on protocells -- their formation, composition, and  capabilities.  I have taken the time to obtain and read the papers (part of my own critical evaluation of Fox's claims).  Anyone can walk me thru the papers and try to show where the data is wrong.  This will be in two posts due to length limitations.

Web sites:
http://www.siu.edu/~protocell/
http://www.theharbinger.org/articles/rel_sci/fox.html
First papers:
    Fox, S.W. and K. Harada. 1958. Thermal copolymerization of amino acids to a product resembling protein. Science 128: 1214.
    Fox, S. W., K. Harada, and J. Kendrick. 1959. Production of spherules from synthetic proteinoids and hot water. Science 129: 1221-1223.
    Hayakawa, T, Windsor, CR, Fox, SW.  Coploymerization of the Leuchs anhydrides of the eithtten amino acides common to proteins.  Arch. Biochem. Biophys. 118: 265-272, 1967.
    Melius, P, Sheng, YY-P.  Thermal condensation of a mixture of six amino acids.  Bioorg. Chem. 4: 385-391, 1975.

Protocells under prebiotic conditions:
    Snyder WD and Fox, SW.  A model for the origin of stable protocells in a primitive alkaline ocean.  BioSystems 7: 222-229, 1975.
   Rohlfing, DL.  Thermal polyamino acids: synthesis at less than 100°C.  Science 193: 68-70, 1976.
   Syren RM, Sanjur A, Fox SW  Proteinoid microspheres more stable in hot than in cold water.  Biosystems 1985;17(4):275-80  (protocells at hydrothermal vents)
   Yanagawa, H. and K. Kobayashi. 1992. An experimental approach to chemical evolution in submarine hydrothermal. systems. Origins of Life and Evolution of the Biosphere 22: 147-159.
   Marshall, W. H. 1994. Hydrothermal synthesis of amino acids. Goechimica et Cosmochimica Acta 58: 2099-2106.
    McAlhaney WW, Rohlfing DL.  Formation of proteinoid microspheres under simulated prebiotic atmospheres and individual gases.  Biosystems 1976 Jul;8(2):45-50
     Fouche-CE Jr; Rohlfing-DL   Thermal polymerization of amino acids under various atmospheres or at low pressures.  Biosystems. 1976 Jul; 8(2): 57-65
   SW Fox, Thermal polymerization of amino-acids and production of formed microparticles on lava.  Nature, 201: 336-337, Jan. 25, 1964.
   Hennon, G, Plaquet, R, Biserte, G. The synthesis of amino acid polymers by thermal condensation at 105° without a catalyst.  Biochimie 57: 1395-1396, 1975.
   Heinz, B, Reid, W.  The formation of chromophores through amino acid thermolysis and their possible role as prebiotic photoreceptors.  BioSystems 14: 33-40, 1981.
  
Structure and internal ordering:
   Turcotte, PA, Paolillo, L, Ferrara, L, Benedetti, E, Andini, S.  Structural characterization of thermal prebiotic polypeptides.  J. Mol. Evol. 7: 105-110, 1976.
   Rohlfing, DL.  Thermal poly-a-amino acids containing low proportions of aspartic acid.  Nature 216: 657-659, 1967.
   Tyagi S, Ponnamperuma C  Nonrandomness in prebiotic peptide synthesis.  J Mol Evol 1990 May;30(5):391-9 
    Melius P. Structure of thermal polymers of amino acids. Biosystems 1982;15(4):275-80 Jul;8(2):45-50
   SW Fox, Stereomolecular interactions and microsystems in experimental protobiogenesis.  BioSystems 7: 22-36, 1975
  SW Fox, Self-sequencing of amino acids and origins of polyfunctional protocells.  Origins of Life, 14: 485-488, 1984.
  Temussi, PA, Paolillo, L, Ferrara, L, Benedetti, I, Aninin, S.  Structural characterization of thermal prebiotic polypeptides.  J. Mol. Evol. 7: 105-110, 1976.
  Pivcova, H, Saudek, V, Drobnik, J, Vlasak, J.  NMR study of poly (aspartic acid) I. a- and b-peptide bonds in poly(aspartic acid) prepared by thermal polycondensation.  Biopolymers 20: 1605-1614, 1981.
  Nakashima, T, Jungck, JR, Fox, SW, Lederer, E, Das, BC.  A test for randomness in peptides isolated from a thermal polyamino acid.  Intl. J. Quantum Chem. QBS4: 65-72, 1977.
   Luque-Romero MM, de Medina LS, Blanco JM.  Fractionation and amino acid composition of an aspartic acid-containing thermal  proteinoid population.  Biosystems. 1986;19(4):267-72.
  Bahn, P. and A. Pappelis. 2001. HPLC evidence of nonrandomness in thermal proteins. In First Steps in the Origin of Life in the Universe. Julián Chela-Flores, Tobias Owen, and François Raulin, eds., Kluwer Academic Publishers, Dordrecht, The Netherlands. Pp. 69-72.
   Bahn, P. and A. Pappelis. 2001. IR spectra of protein, thermal protein, and thermal glycoprotein. In First Steps in the Origin of Life in the Universe. Julián Chela-Flores, Tobias Owen, and François Raulin, eds., Kluwer Academic Publishers, Dordrecht, The Netherlands. Pp.73-76.

Thermal proteins from DL and nonproteinous amino acids
   Saunders MA and Rohlfing DL, Inclusion of nonproteinous amino acids in thermally prepared models for prebiotic protein.  Biosystems 6. 81-92, 1974.
 
Metabolism:
  Rohlfing, DL, Fox, SW.  Catalytic activities of thermal polyanhydro-a-amino acids. Advances Catal. 20: 373-418, 1969.

Hydrolysis (energy gaining):
  p-nitrophenyl acetate
      Fox, S., Harada, K. Rohlfing, DL  The thermal copolymerization of a-amino acids. In Stahmann, MA (ed) Polyamino Acids, Polypeptides, and Proteins (Univ. of Wisconsin Press, Madison) 47-54, 1962
      Rohlfing DL and Fox, SW.  The catalytic activity of thermal polyanhydro-a-amino acids for the hydrolysis of p-nitrophenyl acetate.  Arch. Biochem. Biophys. 118: 127-132, 1967.
      Usdin, VR, Mitz, MA, Killos, PJ.  Inhibition and reactivation of the catalytic activity of a thermal a-amino acid copolymer.  Arch. Biochem. Biophys. 122:  258-261, 1967.
 
  p-nitrophenyl phospate
       Oshima, T.  The catalytic hydrolysis of phosphate ester bonds by thermal polymers of amino acid.  Arch. Biochim. Biophys. 126: 478-485, 1968.
  
  Decarboxylation
       Glururonic acid:  Fox, SW and Krampitz, G.  The catalytic decomposition of glucose in aqueous solution by thermal proteinoids.  Nature 203: 1362-134, 1964
       Pyruvic acid:  Hardebeck, HG, Krampitz, G, Wulf, L.  Decarboxylation of pyruvic acid in aqueous solution by thermal proteinoids.  Arch. Biochem. Biophys.  123: 72-81, 1986.
       Oxaloacetic acid:  Rohlfing, DL  THe catalytic decarboxylation of oxaloacetic acid by thermally prepared poly-a-aminoacids.  ARch. biochem. Biophys. 118: 468-474, 1967.
  
  Deamination
       Krampitz, G, Haas, W. Baas-Diehl, S.  Glutaminsaure-Oxydoreductase-Aktivitat von polyanhydro-a-aminosauren (proteinoiden).  Naturwissenschaften 55: 345-346, 1968.

Anabolism:
   Amination:  Krampitz, g, Baars-Diehl,S, Haas, W, Nakashima,T.  Aminotransferase activity of thermal polylysine.  Experientia 24: 140-142, 1968. 
Kolesnikov, M.P. 1991. Proteinoid microspheres and the process of prebiological, photophosphorylation. Origins of Life and Evolution of the Biosphere 21: 31-37.  ADP + Pi + light  yields ATP
  
    RNA/DNA:  JR Jungck and SW Fox, Synthesis of oligonucleotides by proteinoid microspheres acting on ATP.  Naturwissenschaften, 60: 425-427, 1973.
  
   Peptides:
      T Nakashima and SW Fox, Synthesis of peptides from amino acids and ATP with lysine rich proteinoid.  J. Mol. Evol. 15: 161-168. 1980.
      Fox, SW, Jungck, JR, Nakashima, T. From proteinoid microsphere to contemporary cell: formation of internucleotide and peptide bonds by proteinoid particles. Origins of Life 5: 227-237, 1974.
      Nakashima, T, Fox, SW.  Formation of peptides by single or multiple additions of ATP to suspensions of nucleoproteinoid microparticles.  BioSystems 14: 151-161, 1981.
      Paecht-Horowitz M, Katchalsky A. J  Synthesis of amino acyl-adenylates under prebiotic conditions. Mol Evol 1973;2(2-3):91-8

Oxidoreductions:   H2O2 (catalase) and H2O2 and hydrogen donors (peroxidase reaction)
       Dose, K, Zaki,L.  The peroxidatic and catalase activity of hemoproteinoids. Z. Naterforsch 26b: 144-148, 1971.

   Photoactivated decarboxylation -- glycoxylic acid, glucuronic acid, pyruvic acid.
      Wood, A, Hardebeck, HG.  Light-enhanced decarboxylations by proteinoids. In Rohlfing, DL and Oparin, AI (eds) Molecular Evolution (Plenum, New York), 233-245, 1972. 

  Hormone:  Fox, SW, Wang, C-t.  Melanocyte-stimulating hormone activity in in thermal proteins of a-amino acids.  Science 160: 547-548, 1968.

Compartments within protocells:
  Brooke S, Fox SW. Compartmentalization in proteinoid microspheres.Biosystems. 1977 Jun;9(1):1-22.
  
Photosynthesis:
    Bahn PR, Fox SW.  Models for protocellular photophosphorylation.  Biosystems. 1981;14(1):3-14.
     Masinovsky Z, Lozovaya GI, Sivash AA, Drasner M.  Porphyrin-proteinoid complexes as models of prebiotic photosensitizers.  Biosystems 1989;22(4):305-10.
     Masinovsky Z, Lozovaya GI, Sivash AA.  Some aspects of the early evolution of photosynthesis.  Adv Space Res 1992;12(4):199-205.

Response to stimuli
  Przybylski AT. Excitable cell made of thermal proteinoids. Biosystems 1985;17(4):281-288.
  Vaughan G, Przybylski AT, Fox SW. Thermal proteinoids as excitability-inducing materials. Biosystems. 1987;20(3):219-23.
   Ishima Y, Przybylski AT, Fox SW.  Electrical membrane phenomena in spherules from proteinoid and lecithin.  Biosystems. 1981;13(4):243-51.
  Pappelis, A., S. W. Fox, R. Grubbs, and J. Bozzola. 1998. Animate protocells from inanimate thermal proteins: Visualization of the Process. In Exobiology: Matter, Energy, and Information in the Origin and Evolution of Life in the Universe. J. Chela-Flores and F. Raulin, eds., Kluwer Academic Publishers, Dordrecht, The Netherlands, Pp.195-198.

Growth and Reproduction:
   Fox, SW, McCauley, RJ, Wood, A  A model of primitive heterotrophic proliferation.  Comp. Biochem. Physiol. 20: 773-778, 1967.
   Fox, SW.  Molecular evolution to the first cells. Pure Appld. Chem. 34: 641-669, 1973.
 
Communication:
    Hsu, LL, Brooke, S, Fox, SW.  Conjugation of proteinoid microspheres: a model of primordial communication.  Curr. Mod. Biol. (now BioSystems) 4: 12-25, 1971.

lucaspa · Mar 22, 2003

Protocells as units of evolutionary selection:
Matsuno K Natural self-organization of polynucleotides and polypeptides in protobiogenesis: appearance of a protohypercycle. Biosystems 1982;15(1):1-11
Kenyon, DH. Prefigured ordering and protoselection in the origin of life. In Dose, K, Fox, SW, Deborin, GA, and Pavlovskaya, TE (eds) The Origins of Life and Evolutionary Biochemistry (Plenum Press, New York), 207-220, 1974.
Fox SW. Molecular selection and natural selection. Q Rev Biol. 1986 Sep;61(3):375-86.

Beginnings of genetic code:
Nakashima T, Fox SW. Selective condensation of aminoacyl adenylates by nucleoproteinoidmicroparticles (prebiotic-lysine-model system-genetic code).Proc Natl Acad Sci U S A. 1972 Jan;69(1):106-8.
Yuki A, Fox SW. Selective formation of particles by binding of pyrimidine polyribonucleotides orpurine polyribonucleotides with lysine-rich or arginine-rich proteinoids.Biochem Biophys Res Commun. 1969 Aug 15;36(4):656-63.

Protocells as new domain of life
Pappelis A, Fox SW. Domain Protolife. Journal of Biological Physics 20: 129-132, 1994.
http://www.asa3.org/archive/evolution/199907/0062.html

lucaspa · Mar 22, 2003

A number of objections have been raised to the protocells in the forum. 

1.  "the statements being made these days about Fox's claims is dismissive, not favorable. "

I have looked thru the web. The following are couse notes, textbooks, and other sources where Fox's claims are not dismissed. The list is by no means exhaustive because I haven't completed the research yet.

http://www.resa.net/nasa/origins_life.htm

Courses mentioning protocells:
http://faculty.uca.edu/~johnc/cellev.htm
http://www.mhhe.com/biosci/genbio/maderbio6e/outlines/ch20out.mhtml
http://www1.br.cc.va.us/monger/Biology/Lecture/OriginandHistoryofLIfe.htm
http://www.gpc.peachnet.edu/~larmstea/1403originlifenot1.html
http://www.tufts.edu/as/wright_center/cosmic_evolution/docs/text/text_chem_4.html
http://www.tufts.edu/as/wright_center/cosmic_evolution/docs/text/text_chem_5.html
http://www.xs4all.nl/~sbpoley/abiog/virginiaorigin.htm
http://www.bios.niu.edu/Parrish/205.htm
www.kpbsd.k12.ak.us/sohi/rife/AP%20Biology/ AP%20Bio%20Ch%2016%20CMR%20Lect%20'00%20-.DOC
www.greenvilletech.com/biology/LesleyWilson/ Bio102Ch16notes.doc
http://www.bios.niu.edu/Parrish/205.htm
http://www.physics.queensu.ca/~phys214/lecture10.html
 http://dekalb.dc.peachnet.edu/~jaliff/evolutn.htm

Textbooks mentioning protocells
http://www.mhhe.com/biosci/genbio/maderbio6e/outlines/ch20out.mhtml
http://www.mhhe.com/biosci/genbio/raven6b/graphics/raven06b/other/ch04.pdf
http://www.planetarybiology.com/download/origin_of_earth_and_life.pdf
Principles of Cell and Molecular Biology_, Second Edition (1995) by Lewis J. Kleinsmith and Valerie M. Kish.

 

 

lucaspa · Mar 22, 2003

2. Protocells aren't like "real" cells.  Summarized in DNAunion's statement: "my objections to their being actual living cells is NOT based on contemporary cells it is based on cells in general, even those that existed billions of years ago."

"In trains of electrical spiking action potentials are beginning to have a bedside flavor for a cardiology ward. Dr. Yoshio Ishima of the Tokyo Medical School studied those displaying regular rhythm and said he could not distinguish some from the recording of a heart. Hundreds of types of microspheres made from thermal protein all exhibit electrical activity. The principal ways in which the laboratory protocell meets the definition of life in the dictionary are in displaying growth, metabolism, reproduction and responsiveness in cells made by synthesis. By the process of cellular engineering, we can do a more meaningful job of arriving at a definition of life than by describing behavior of modern cells. This is a theme in a recent book titled Defining Life edited by Professor Martino Rizzotti of Padova, Italy, 1996. "  http://www.skeptictank.org/sidfox.htm

Look at that. Electrical activity that can't be told from heart cells!

"the coagulations do seem to resemble morphologically some of the most ancient microfossils as well as modern blue-green algae cells. These curious chemical proteinoids appear to possess many of the attributes of bona fide living organisms: they are cell-like spheres a few microns across, each possessing a thick shell-like membrane; most even appear to exhibit a primitive metabolism, with some dissipating away while others swell and bud (fig. 4). "  http://history.nasa.gov/CP-2156/ch0.htm

"They have a shape and size similar to bacteria, they have osmotic properties, they can catalyze some kinds of chemical reactions in their interiors, they grow and divide like coacervates, they have a selectively semipermeable double outer layer similar to a cell membrane, they take in polynucleotides, and they even exhibit primitive metabolic pathways."  http://pw1.netcom.com/~rogermw/Reich/bions.html

"microspheres have two-layered boundary which is osmoticallyactive, are gram - when stained"  http://www.anselm.edu/homepage/jpitocch/evolution/evolmacroevolution.html

Look at that one again.  Protocells are gram negative just like modern bacteria!

"microscopic examination they looked like tiny spherical (coccoid) bacteria, and were of the same size as such organisms. Taking time-lapse moving pictures of them, he believed he saw them undergo fision, or division of one globule into two. He called the coccoid objects proteinoids. He then examined them under the electron microscope. This revealed that these proteinoids possessed a membrane structure strikingly like that seen in cells. "  http://www.redlandsfortnightly.org/howell90.htm

"Florida biologist Sidney W. Fox has shown that simple heating of dry amino acids (as might happen on a dry planet) can create protein molecules. Once water is added, these proteins form the round, cell-like objects called microspheres, which take in material from the surrounding liquid, grow by attaching to each other, and divide. ..., microspheres resemble bacteria so much that experts have trouble distinguishing them by appearance."  http://zeno.as.arizona.edu/~lknutson/webdan/Textbook/CHAP_28.html%25

Aceldama · Mar 22, 2003

I had to re-read that a few times to understand it but it was worth it! Lucaspa your real cool! Although you most likely won't have a creationist reply to this thread, your hard work on this forum will open many minds and enhance everyones knowledge of the sciences.  

Three cheers for Lucaspa everyone!

 

webboffin · Mar 22, 2003

Dunno been through all this before

Taffsadar · Mar 22, 2003

Today at 12:03 AM webboffin said this in Post #6

Dunno been through all this before

So you avoid this one? Smart move, loosing is never funny.

Late_Cretaceous · Mar 24, 2003

I guess you just can't argue with all that evidence. Well, acutally you can. You could conduct research that would ultimately support of defeat the conclusions raised by these papers. You could also analyze the papers themselfs to find flaws in the methodology, statistical analysis or conclusions. Of couse this all takes time, which is probably what some diligent creationists are doing right now - and which is why none have posted any comprehensive rebuttals. Yet.

And now we wait.

DNAunion · Mar 24, 2003

Proteinoids (objections to their relevance)
Another, this time more skeptical, background quote will be provided.

Biochemists knew that when a mixture of amino acids in the ratio found in proteins was heated, the result was pyrolysis to a dark brown tar with a disagreeable odor, commented chemist William Day. At this point Sidney Fox made a contribution. Fox set aside the usual recipes and added extra amounts of any of three special amino acids. These mixtures, when heated in the dry state well above the boiling point of water, gave clean preparations, in which amino acids had united with one another. The products obtained were not natural proteins, however, even though they were made from amino acids. The special amino acids mentioned above contained either an extra amino or an extra acid group. In normal proteins, these extra groups do not take part in chain formation, but this had occurred in the heating process. Unnatural chains, even branched chains, had been produced. Further, some of the amino acids had been converted into their mirror-image forms, so both types were present. Others had been converted to colored substances, pigments, which were also built into the chains. The term proteinoid rather than protein was
applied to the product, because of these features which distinguished it from anything present in earthly biology. (Origins: A Skeptics Guide to the Creation of Life on Earth, Robert Shapiro, Bantam Books, 1987, p193-194)

Proteinoids are not proteins since: (1) their structures are branched because many bonds form between the wrong functional groups, (2) they contain both enantiomeric forms of amino acids, and (3) their sequences are not repeatable. And because no template is used for their production, proteinoids also lack genetic continuity: as a result, their ability to evolve is severely restricted, if it exists at all. In addition, despite Foxs claims, their geological relevance is doubtful (that is, the conditions required for their production are considered by many to be unlikely in a real prebiotic setting).

Few origin-of-life experts are as sanguine as Fox concerning the significance of his results. It has been objected that the conditions required for the formation of proteinoids are not likely to have obtained on the prebiotic Earth, that the resulting material has more in common with primeval goo than with proteins, and that the microspheres are a far cry from anything that could be called a cell. (Christian de Duve, Vital Dust:Life as a Cosmic Imperative, Basic Books, 1995, p29)

[Foxs proteinoid microsphere] system has received favorable attention in the media and in a number of texts, most notably A. L. Lehningers widely used Biochemistry, which termed it remarkable. On the other hand, it has attracted a number of vehement critics, ranging from the chemist Stanley Miller and astronomers Harold Urey and Carl Sagan to Creationist Duane Gish. On perhaps no other point in the origin-of-life theory could we find such harmony between evolutionists and Creationists as in opposing the relevance of the experiments of Sidney Fox. (Origins: A Skeptics Guide to the Creation of Life on Earth, Robert Shapiro, Bantam Books, 1987, p192)

For instance, the polymerization reaction studied mainly by S. Fox (Fox and Dose, 1977) involves heating a mixture of amino acids, characterized by an excess of aspartic and glutamic acids, at 150[degrees]C to 180[degrees]C for a few hours. The polypeptide formation is described (see Miller, 1992) as follows: [details omitted] The plausibility of the reaction (dry heating) has been questioned by several researchers (see Miller, 1992). The relevance of the resulting proteinoids to the origin of life will be discussed in chapter 22 [where it is said that proteinoids are irrelevant to the origin of life see the following quote from page 284]. (Noam Lahav, Biogenesis: Theories of Lifes Origins, Oxford University Press, 1999, p167)

As noted in chapter 19, the proteinoids are not considered relevant to the origin of life by most researchers (Noam Lahav, Biogenesis: Theories of Lifes Origins, Oxford University Press, 1999, p284)

DNAunion · Mar 24, 2003

Three Amino Acids Require Special Conditions
Three of the twenty amino acids found in contemporary cells decompose easily during the process of proteinoid formation.

"The amino acids not represented in proteinoids in the proportions usually found in proteins were cystine, serine, and threonine. These latter were largely, although not entirely, decomposed." (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p148)

Special measures must be taken in order for these three amino acids to be present in the final product.

"Inclusion in the polymeric product of several percent of serine, threonine, cysteine, or cystine can be accomplished by carrying out the condensation at lower temperatures, such as 130oC, and by including polyphosphoric acid to conserve cysteine or cystine (Genaux et al., 1967) or sodium polyphosphate (Dose and Rauchfuss, 1972). These amino acids are otherwise almost completely destroyed." (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p152)

Incorrect Bonds and Branching
In biological proteins, only alpha-peptide bonds occur. But in proteinoids, other forms exist as well.

"Sidney Fox found that by heating and drying a mixture of amino acids, and then dissolving the mixture in water, he could obtain strings of amino acids displaying weak catalytic activity. Unfortunately, however, the amino acids were linked in a variety of different ways, and not only by peptide bonds.¨ (The Origins of Life: From the Birth of Life to the Origin of Language, John Maynard Smith & Eors Szathmary, Oxford University Press, NY, 1999, p 32)

K studies using nuclear magnetic resonance (NMR) have shown that thermal proteinoids have scarce resemblance to natural peptidic material because [beta], [gamma], and [epsilon] bonds largely predominate over [alpha]-peptide bonds" (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [BS in Chemistry, Ph.D. in Geochemistry], The Mystery of Life's Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p155-156).

"A third kind of question [concerning proteinoids] was that of crosslinks such as have not been reported for protein. Reactions might be postulated, for example, between side chains of such amino acids as lysine and aspartic acid. Moreover, linkage through the Õ-amino groups of some lysine residues has been shown in a number of studies (Harada, 1959; Harada and Fox, 1965a; Suzuki, 1966; Heinrich et al., 1969)." (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p148-149)

DNAunion · Mar 24, 2003

Both Enantiomers of Amino Acids

Fox has produced some quite long peptides, which he terms proteinoids, using this method. Unfortunately, the resemblance between Foxs proteinoids and real proteins is rather superficial. For example, real proteins are made exclusively of left-handed amino acids (see page 71), whereas proteinoids are an equal mixture of left and right. (The Fifth Miracle: The Search for the Origin and Meaning of Life, Paul Davies, Simon & Schuster, NY, 1999, p 90-91)

thermal proteinoids are composed of approximately equal numbers of L- and D-amino acids in contrast to viable proteins with all L-amino acids. (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [BS in Chemistry, Ph.D. in Geochemistry], The Mystery of Lifes Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p155-156).

Before reading the next quote, one needs to have a basic understanding of the process of racemization. As explained elsewhere, amino acids come in two enantiomeric forms designated L- (left handed) and D- (right handed). A mixture that contains equal amounts of both forms is said to be racemic, while a mixture that contains only one of the forms is said to be pure (or resolved). If one starts with a pure mixture of L-amino acids and during the series of reactions some of them are converted into D- amino acids, such that the result is a racemic (50/50) mixture, then (complete) racemization has occurred.

Many proteinoids have been made from mixtures of DL amino acids. When some of the reactant amino acids are of the L configuration, much racemization occurs. This racemization, though substantial, is, however, incomplete under conditions used for the production of proteinoids. A typical proteinoid made from eighteen amino acids had [an optical activity of -5.6 degrees]. Under the usual conditions for pyrocondensation, L-aspartic acid is entirely racemized, while L-glutamic acid, L-leucine, and L-isoleucine are only partly racemized (Fox and Harada, 1960; Fox et al., 196; Rohlfing, 1967a). (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p163-164)

DNAunion · Mar 24, 2003

Unlikely Conditions for Formation

The scientific community has remained deeply skeptical of these experiments. As with our imaginary baker, a heavy odor of investigator involvement hangs over proteinoids. The special circumstance needed to make them hot, dry conditions (putatively representing rare spots (such as volcano rims) with exact amounts of already-purified amino acids weighed out in advance casts dark shadows over the relevance of the experiments. Worse, because proteinoids are not really proteins, the considerable problem of producing authentic [prebiotic] proteins remains. (Michael J. Behe, Darwins Black Box: The Biochemical Challenge to Evolution, Free Press, 1996, p170)

the geological conditions indicated are too unreasonable to be taken seriously. As Folsome has commented, The central question [concerning Foxs proteinoids] is where did all those pure, dry, concentrated, and optically active amino acids come from in the real, abiological world? (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [BS in Chemistry, Ph.D. in Geochemistry], The Mystery of Lifes Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p155-156).

DNAunion · Mar 24, 2003

Sequence Not Repeatable No Genetic Continuity and No Ability to Evolve

Since peptide bonds are thermodynamically unstable in aqueous solutions, once a primitive proteinoid arose, it would be highly susceptible to hydrolytic breakdown in the warm primordial sea. Thus no single proteinoid molecule could be expected to survive for long. This fact raises a fundamental problem. It is difficult to see how any given proteinoid could have undergone residue-by-residue evolutionary improvement to an amino acid sequence better able to survive if each proteinoid molecule lasted but a short period and if there were no means of recording or replicating the amino acid sequence of the better proteinoids. This follows from mathematical considerations alone. In all the organisms known today there are only about 10^12 different types of proteins, whereas over 10300 different types of proteins can theoretically be formed from 20 different amino acids. (Biochemistry: Second Edition, Albert L. Lehninger, Worth Publishers, 1975, p1041)

there is no evidence that proteinoids differ significantly from a random sequence of amino acids, with little or no catalytic activity. (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [BS in Chemistry, Ph.D. in Geochemistry], The Mystery of Lifes Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p155-156).

DNAunion · Mar 24, 2003

Proteinoid Microspheres (objections to their relevance)

Individual proteinoids can be coaxed into undergoing further physical changes that result in a spherical structure of bacterial size. These structures, called proteinoid microspheres, are claimed to possess many cell-like properties: but they dont.

Actually, [proteinoid] microspheres posses only outward likenesses and nothing of the inward structures of a true cell. They contain no information content, no energy utilizing system, no enzymes, no nucleic acid, no genetic code, and no replication system. They contain only a mixture of polymers of amino acids, the so-called proteinoids. Microspheres cannot be said to be living in any sense of the word, and it is questionable whether they should even be given the name protocell. They are merely an aggregation of [non-proteinous] polymers, and do not help to bridge the gap between life and non-life. (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [BS in Chemistry, Ph.D. in Geochemistry], The Mystery of Lifes Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p176).

Foxs hypothesis is controversial today, as it was when first published. It is adequate to cite Ferris (1989), who wrote: Foxs theory has little validity. Consequently, the other claims - on the significance of the budding of microspheres, their implied sexuality, the membrane potentials and so on are meaningless in the context of the origin of life. More information, and critical comments, may be found in R. F. Fox, 1988; Brack, 1993b; and Yockey, 1992. (Noam Lahav, Biogenesis: Theories of Lifes Origins, Oxford University Press, 1999, p242)

We must note here that [proteinoid] microspheres provide a fine illustration for the phrase easy come easy go. They can be dissolved quite readily by changing the acidity of the solution in which they were formed, or by adding additional water to that solution. It was this fragility that suggested the bubble analogy to me. (Origins: A Skeptics Guide to the Creation of Life on Earth, Robert Shapiro, Bantam Books, 1987, p194)

Few origin-of-life experts are as sanguine as Fox concerning the significance of his results. It has been objected that the conditions required for the formation of proteinoids are not likely to have obtained on the prebiotic Earth, that the resulting material has more in common with primeval goo than with proteins, and that the microspheres are a far cry from anything that could be called a cell. (Also quoted previously in the section specifically addressing the shortcomings of proteinoids themselves: Christian de Duve, Vital Dust:Life as a Cosmic Imperative, Basic Books, 1995, p29)

Perhaps Dean Kenyon summarizes the flaws of proteinoid microspheres the best.

I know that if you look into the chemical composition of these microsystems you find little that reminds you of the chemical complexity of cells. There is generally no protein present proteinoid is present, but that is not the same as genuine protein it does have amino acids in it but there are many chemical differences between proteinoids and proteins. There are no nucleic acids in these systems, no polysaccharides, no lipids, there is no metabolism going on, they are chemically inert, theres no genetic information whatsoever, in my view, in these microsystems, they are not self-replicating units, they have no energy capture or processing capabilities. So when you run down that list of negative features, you come away pretty much with the view that these proteinoid microsystems probably didnt have anything to do with the origin of life. (Focus on the Origin of Life, An Interview with Dean H. Kenyon, Professor of Biology, San Francisco State University, 1994, VHS Tape from Access Research Network, http://www.arn.org)

DNAunion · Mar 24, 2003

Metabolism?

It is sometimes claimed that proteinoid microspheres metabolize. If this claim is meant to relate somehow to cellular metabolism, it is false.

In the present-day cell, there are thousands of different chemical reactions taking place. Not even one chemical reaction takes place in microspheres, only mechanical and physical processes due to simple attractive forces. (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [BS in Chemistry, Ph.D. in Geochemistry], The Mystery of Lifes Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p175).

And surely Fox would not make the following statement if his proteinoid microspheres could already metabolize:

metabolism could have evolved much more effectively from a proteinoid type of polymer than from a highly specialized type of contemporary protein. (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p172)

A likely explanation for this apparent misunderstanding by proteinoid microsphere supporters is that in some experiments, the microspheres did metabolize: but the reactions were actually carried out by enzymes extracted from true cells, and not by proteinoids themselves.

In some cases enzymes isolated from living cells are used instead of artificially synthesized proteinoids. A collection of enzymes is far from being a living cell even though the enzymes were produced by a cell. A microsphere incorporating a suitable group of enzymes can mimic a metabolic pathway. For example, a microsphere can be prepared containing an enzyme that catalyzes the formation of starch by polymerization of the simple sugar glucose. Another microsphere can be formed under the same conditions, differing from the first only by the addition of another enzyme that catalyzes the breakdown of starch to maltose, another carbohydrate. (Biochemistry, Mary K. Campbell, Saunders College Publishing, 1991, p 15-16)

DNAunion · Mar 24, 2003

Growth?

Cells that are actively progressing through the cell cycle undergo growth prior to division. This growth comes from within, as synthesis of proteins, DNA, and organelles occurs. Proteinoid microspheres, on the other hand, do not grow in a biological sense they grow from the outside as simple attractive forces cause free proteinoids to aggregate to the microspheres and accrete on them.

[Foxs proteinoid microspheres] grow by accretion. This, however, is the attraction of like molecules to the micelle by simple physical forces. The process of microsphere growth has little if any similarity to the process by which contemporary cells grow. True cells grow through a metabolic process involving many chemical reactions. In microspheres no chemical reactions are taking place, only accumulation through physical forces of attraction. (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [BS in Chemistry, Ph.D. in Geochemistry], The Mystery of Lifes Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p175).

GROWTH BY ACCRETION. Liberated buds, proteinoid endomicroparticles (smaller particles within microspheres), nucleoproteinoid particles, etc. can function as centers, or as physical nuclei, for the growth of larger microparticles. Growth by accretion from crystal violet-stained buds is shown in Figure 6-15. (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p213)

DNAunion · Mar 24, 2003

Binary Fission?

Another claim is that proteinoid microspheres can reproduce by binary fission. This process is also unrelated to the true biological processes.

[Proteinoid microspheres] can be induced to undergo cleavage or division by suitable changes in pH or when exposed to MgCl2. (Biochemistry: Second Edition, Albert L. Lehninger, Worth Publishers, 1975, p1047)

When the pH of a suspension of proteinoid microspheres made from acidic proteinoid is raised by 1-2 units, several phenomena are observed. Another is the fission into two particles, which is also described in more detail later (page 209). (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p205-206)

An external stimulus, such as a change in the pH, can cause them to divide but there are no internal mechanisms behind this process.

A kind of binary fission has been observed in acidic proteinoid microspheres, although not documented photographically to the stage of separation into daughter particles (Figure 6-11; Fox, 1968). One difficulty in experiments of this type is that elevated pH leads also to gradual or rapid dissolution of the proteinoid. More recent experiments (Brooke and Fox, 1970) demonstrate that binary fission, which is attributable to surface tension, can occur without substantial dissolution by use of pure water or heat on calcium-containing proteinoid microspheres. The tendency of variously composed particles in the range of size greater than the colloid range is to divide into two. This tendency is observed in soap droplets, mercury droplets, oil droplets, and it occurs in molten glass droplets on the Moon (Fox et al., 1970) as well as in proteinoid microspheres and in contemporary cells. (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p209-210)

So the division is not caused by any kind of a biological trigger, but rather by either merely exceeding a physical threshold (the microspheres enlarge to a point where the volume-to-surface-area ratio becomes too great and they split) or by manipulations of the pH.

DNAunion · Mar 24, 2003

Bud Like Yeasts?

Another form of putative reproduction is that the budding process of proteinoid microspheres is similar to that of yeasts. This flawed belief is most likely due to the following sentence, from Lehningers first edition of Biochemistry:

Moreover, if suspensions of microspheres are allowed to stand for 1 or 2 weeks, they undergo a budding process, akin to that of yeasts. (Biochemistry, Albert L. Lehninger)

However, in his next edition, Lehninger modified that sentence, leaving off the words akin to that of yeasts. It should be pointed out that the reference to yeasts was not simply moved to a preceding or following sentence and/or paragraph it was dropped completely.

Moreover, if suspensions of microspheres are allowed to stand for 1 or 2 weeks, they undergo a budding process. (Biochemistry: Second Edition, Albert L. Lehninger, Worth Publishers, 1975, p1047)

Others have noted the dissimilarities between the budding of proteinoid microspheres and yeasts.

Buds appear spontaneously on proteinoid microspheres allowed to stand in their mother liquor. These buds have the appearance and consistency of those found on yeast and bacteria, but they are, of course, lacking in the total essential metabolic properties of yeasts (Fox et al., 1967). (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p212)

That the buds do not have the metabolic properties of yeasts is only logical since proteinoid microspheres themselves do not metabolize.

In budding experiments, microspheres are placed in solutions saturated with proteinoid. As proteinoid accretes on their surface, they expand and form buds. Mechanical agitation of the suspension causes the buds to be split off. When the buds are placed in fresh protein they grow, forming a second generation. (Origins: A Skeptics Guide to the Creation of Life on Earth, Robert Shapiro, Bantam Books, 1987, p195)

Buds form spontaneously because of mere physical attraction of nearby, unbound proteinoids. That is not how yeasts form their buds. In addition, yeasts do not require mechanical agitation for their buds to become detached.

[Buds] can be released from their parent microspheres when a suspension of the joint particles is subjected to mild warming, sparking with a Tesla coil, or mechanical shock. (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p212)

Yeasts dont need to have someone heat them, spark them with electricity, or physically jolt them for their buds to separate.

[Proteinoid microspheres] propagation by budding also has no connection to the present day cell process of reproduction, which requires enzymes, DNA, energy, and many reactions coupled together precisely. By contrast, the budding illustrated by microspheres is merely a breaking up of the microsphere due to heat or pH changes. (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [BS in Chemistry, Ph.D. in Geochemistry], The Mystery of Lifes Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p175).

Reproduction (Summary)
Even Fox refrains from attributing proteinoid microsphere reproduction to biological mechanisms.

Also inherent in the proteinoid microsphere is the tendency to participate in the reproduction of its own likeness. This sequence of processes seems to be closer, in many respects, to simple physical phenomena, than to the complex concomitance of events associated with contemporary reproduction. (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p251)

DNAunion · Mar 24, 2003

Synthesize Proteins?

The most outright refutation of the claim that proteinoid microspheres can produce protein comes directly from Fox himself.

The [proteinoid microsphere] units studied are unable to manufacture protein, which they must instead obtain preformed from the environment. (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p213)

A further indication that proteinoid microspheres cannot synthesize their own protein is stated by Fox later in his book, in a section entitled Evolution from the Protocell to the Contemporary Cell:

A more independent and adaptable cell arose, however, when some protocells acquired the ability to produce their own polyamino acids internally. These would have had to be a more contemporary type, in which the instructions from one generation to a descendant generation were channeled through the parents as individuals rather than being drawn from the monomers and their polymers in the environment. (Molecular Evolution and the Origin of Life, Sidney W. Fox and Klaus Dose, W. H. Freeman and Co., 1972, p246)

One needs to keep in mind several points when he or she encounters a statement such as the following.

Moreover, it is striking that amino-acyl adenylates yield oligopeptides when incubated with proteinoid-polynucleotide complexes, which thus have some of the characteristics of ribosomes. (Biochemistry: Second Edition, Albert L. Lehninger, Worth Publishers, 1975, p1047)

First, the mentioned amino acids that join to form an oligopeptide are pre-activated it is not the protoribosome itself that performs this task. In addition, the protoribosome was not composed simply of proteinoid it also contained polynucleotides, which have not been synthesized under any plausible prebiotic conditions, let alone under those dry, high-heat conditions associated with proteinoid formation.

DNAunion · Mar 24, 2003

Cell-Like Membrane?

Cells have membranes in which phospholipids are the primary structural component, and in which membrane-spanning proteins transport materials across the barrier the membrane forms. However, the membranes of proteinoid microsphere are lipid-free and do not carry out the functions of cellular membranes.

[Stanley] Miller and [Leslie] Orgel also criticize Foxs statements relating microspheres to living cells. They state that the microspheres bilayer membranes are not biological-like membranes since they do not contain lipids or carry out any of the functions of biological membranes. They conclude, It seems unlikely that the division of microspheres is related to the origin of cell division. (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [BS in Chemistry, Ph.D. in Geochemistry], The Mystery of Lifes Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p175).

Folsome criticized microspheres in that they possess a grossly thick boundary layer that more closely resembles a nearly impermeable cell wall or spore coat than a cell membrane. (Charles B. Thaxton [Ph.D. in Chemistry], Walter L. Bradley [Ph.D. in Materials Science], Roger L. Olsen [BS in Chemistry, Ph.D. in Geochemistry], The Mystery of Lifes Origin: Reassessing Current Theories, Lewis and Stanley, 1984, p175).

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