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Prebiotic synthesis of methionine and other sulfur-containing organic compounds on the primitive Earth: a contemporary reassessment based on an unpublished 1958 Stanley Miller experiment.

Parker ET, Cleaves HJ, Callahan MP, Dworkin JP, Glavin DP, Lazcano A, Bada JL - Orig Life Evol Biosph (2010)

Bottom Line: The extracts were produced by the action of an electric discharge on a mixture of methane (CH(4)), hydrogen sulfide (H(2)S), ammonia (NH(3)), and carbon dioxide (CO(2)).Racemic methionine was formed in significant yields, together with other sulfur-bearing organic compounds.The formation of methionine and other compounds from a model prebiotic atmosphere that contained H(2)S suggests that this type of synthesis is robust under reducing conditions, which may have existed either in the global primitive atmosphere or in localized volcanic environments on the early Earth.

View Article: PubMed Central - PubMed

Affiliation: Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093, USA.

ABSTRACT
Original extracts from an unpublished 1958 experiment conducted by the late Stanley L. Miller were recently found and analyzed using modern state-of-the-art analytical methods. The extracts were produced by the action of an electric discharge on a mixture of methane (CH(4)), hydrogen sulfide (H(2)S), ammonia (NH(3)), and carbon dioxide (CO(2)). Racemic methionine was formed in significant yields, together with other sulfur-bearing organic compounds. The formation of methionine and other compounds from a model prebiotic atmosphere that contained H(2)S suggests that this type of synthesis is robust under reducing conditions, which may have existed either in the global primitive atmosphere or in localized volcanic environments on the early Earth. The presence of a wide array of sulfur-containing organic compounds produced by the decomposition of methionine and cysteine indicates that in addition to abiotic synthetic processes, degradation of organic compounds on the primordial Earth could have been important in diversifying the inventory of molecules of biochemical significance not readily formed from other abiotic reactions, or derived from extraterrestrial delivery.

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Sample chromatogram and mass spectra traces for 6 sulfur compounds detected in Miller’s original sample extracts. All chromatogram traces displayed resulted from selective ion monitoring analysis except the methionine chromatogram trace, which was produced by HPLC-UV analysis. The chromatograms obtained by selective ion monitoring are plotted as signal intensity versus time, whereas the methionine chromatogram obtained by HPLC-UV is plotted as fluorescence sensitivity versus time. In each chromatogram, the asterisk demarcates the detection of the species in question. The mass spectra traces that accompany each chromatogram were obtained using ToF-MS analysis and are plotted as spectral intensity versus mass. Mass spectra traces were used to verify the sulfur distribution of the organosulfur species identified during selective ion monitoring. In all cases, the bottom mass spectra trace is the standard trace and the top mass spectra trace is the experimental trace. In each mass spectra trace, the underlined mass is the parent mass in question. Note: RT is retention time and MA is methylamine
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Fig1: Sample chromatogram and mass spectra traces for 6 sulfur compounds detected in Miller’s original sample extracts. All chromatogram traces displayed resulted from selective ion monitoring analysis except the methionine chromatogram trace, which was produced by HPLC-UV analysis. The chromatograms obtained by selective ion monitoring are plotted as signal intensity versus time, whereas the methionine chromatogram obtained by HPLC-UV is plotted as fluorescence sensitivity versus time. In each chromatogram, the asterisk demarcates the detection of the species in question. The mass spectra traces that accompany each chromatogram were obtained using ToF-MS analysis and are plotted as spectral intensity versus mass. Mass spectra traces were used to verify the sulfur distribution of the organosulfur species identified during selective ion monitoring. In all cases, the bottom mass spectra trace is the standard trace and the top mass spectra trace is the experimental trace. In each mass spectra trace, the underlined mass is the parent mass in question. Note: RT is retention time and MA is methylamine

Mentions: Typical LC-FD/ToF-MS chromatograms and mass spectra detailing the detection of the various sulfur-bearing organic compounds in Miller’s original 1958 sample fractions are shown in Fig. 1. A summary of the recoveries of these sulfur-containing compounds relative to glycine is shown in Fig. 2 (a more extensive manuscript describing the entire suite of amino acids and amines detected in this experiment is in preparation). The observation that chiral amino acids were racemic within the precision of the measurements, combined with the fact that racemization is far too slow of a process to produce racemic mixtures of chiral amino acids over the time span that the sample extracts were stored (Bada 1991), provide evidence that the species detected here are a product of the experiment and not contamination. Additionally, other amino acids detected in the mixture, namely the butyric acid isomers (detected here, but described in detail in another manuscript in preparation) are not common biological compounds. We were not able to calculate absolute yields for the various amino acids because there was no record of how much of the solution from the experiment was saved. However, Van Trump and Miller (1972) gave the yield of glycine from a similar experiment (based on carbon added as methane) as 0.068%.Fig. 1


Prebiotic synthesis of methionine and other sulfur-containing organic compounds on the primitive Earth: a contemporary reassessment based on an unpublished 1958 Stanley Miller experiment.

Parker ET, Cleaves HJ, Callahan MP, Dworkin JP, Glavin DP, Lazcano A, Bada JL - Orig Life Evol Biosph (2010)

Sample chromatogram and mass spectra traces for 6 sulfur compounds detected in Miller’s original sample extracts. All chromatogram traces displayed resulted from selective ion monitoring analysis except the methionine chromatogram trace, which was produced by HPLC-UV analysis. The chromatograms obtained by selective ion monitoring are plotted as signal intensity versus time, whereas the methionine chromatogram obtained by HPLC-UV is plotted as fluorescence sensitivity versus time. In each chromatogram, the asterisk demarcates the detection of the species in question. The mass spectra traces that accompany each chromatogram were obtained using ToF-MS analysis and are plotted as spectral intensity versus mass. Mass spectra traces were used to verify the sulfur distribution of the organosulfur species identified during selective ion monitoring. In all cases, the bottom mass spectra trace is the standard trace and the top mass spectra trace is the experimental trace. In each mass spectra trace, the underlined mass is the parent mass in question. Note: RT is retention time and MA is methylamine
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3094541&req=5

Fig1: Sample chromatogram and mass spectra traces for 6 sulfur compounds detected in Miller’s original sample extracts. All chromatogram traces displayed resulted from selective ion monitoring analysis except the methionine chromatogram trace, which was produced by HPLC-UV analysis. The chromatograms obtained by selective ion monitoring are plotted as signal intensity versus time, whereas the methionine chromatogram obtained by HPLC-UV is plotted as fluorescence sensitivity versus time. In each chromatogram, the asterisk demarcates the detection of the species in question. The mass spectra traces that accompany each chromatogram were obtained using ToF-MS analysis and are plotted as spectral intensity versus mass. Mass spectra traces were used to verify the sulfur distribution of the organosulfur species identified during selective ion monitoring. In all cases, the bottom mass spectra trace is the standard trace and the top mass spectra trace is the experimental trace. In each mass spectra trace, the underlined mass is the parent mass in question. Note: RT is retention time and MA is methylamine
Mentions: Typical LC-FD/ToF-MS chromatograms and mass spectra detailing the detection of the various sulfur-bearing organic compounds in Miller’s original 1958 sample fractions are shown in Fig. 1. A summary of the recoveries of these sulfur-containing compounds relative to glycine is shown in Fig. 2 (a more extensive manuscript describing the entire suite of amino acids and amines detected in this experiment is in preparation). The observation that chiral amino acids were racemic within the precision of the measurements, combined with the fact that racemization is far too slow of a process to produce racemic mixtures of chiral amino acids over the time span that the sample extracts were stored (Bada 1991), provide evidence that the species detected here are a product of the experiment and not contamination. Additionally, other amino acids detected in the mixture, namely the butyric acid isomers (detected here, but described in detail in another manuscript in preparation) are not common biological compounds. We were not able to calculate absolute yields for the various amino acids because there was no record of how much of the solution from the experiment was saved. However, Van Trump and Miller (1972) gave the yield of glycine from a similar experiment (based on carbon added as methane) as 0.068%.Fig. 1

Bottom Line: The extracts were produced by the action of an electric discharge on a mixture of methane (CH(4)), hydrogen sulfide (H(2)S), ammonia (NH(3)), and carbon dioxide (CO(2)).Racemic methionine was formed in significant yields, together with other sulfur-bearing organic compounds.The formation of methionine and other compounds from a model prebiotic atmosphere that contained H(2)S suggests that this type of synthesis is robust under reducing conditions, which may have existed either in the global primitive atmosphere or in localized volcanic environments on the early Earth.

View Article: PubMed Central - PubMed

Affiliation: Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093, USA.

ABSTRACT
Original extracts from an unpublished 1958 experiment conducted by the late Stanley L. Miller were recently found and analyzed using modern state-of-the-art analytical methods. The extracts were produced by the action of an electric discharge on a mixture of methane (CH(4)), hydrogen sulfide (H(2)S), ammonia (NH(3)), and carbon dioxide (CO(2)). Racemic methionine was formed in significant yields, together with other sulfur-bearing organic compounds. The formation of methionine and other compounds from a model prebiotic atmosphere that contained H(2)S suggests that this type of synthesis is robust under reducing conditions, which may have existed either in the global primitive atmosphere or in localized volcanic environments on the early Earth. The presence of a wide array of sulfur-containing organic compounds produced by the decomposition of methionine and cysteine indicates that in addition to abiotic synthetic processes, degradation of organic compounds on the primordial Earth could have been important in diversifying the inventory of molecules of biochemical significance not readily formed from other abiotic reactions, or derived from extraterrestrial delivery.

Show MeSH
Related in: MedlinePlus