Prebiotic synthesis of cysteine peptides that catalyze peptide ligation in neutral water
- PMID: 33184216
- DOI: 10.1126/science.abd5680
Prebiotic synthesis of cysteine peptides that catalyze peptide ligation in neutral water
Abstract
Peptide biosynthesis is performed by ribosomes and several other classes of enzymes, but a simple chemical synthesis may have created the first peptides at the origins of life. α-Aminonitriles-prebiotic α-amino acid precursors-are generally produced by Strecker reactions. However, cysteine's aminothiol is incompatible with nitriles. Consequently, cysteine nitrile is not stable, and cysteine has been proposed to be a product of evolution, not prebiotic chemistry. We now report a high-yielding, prebiotic synthesis of cysteine peptides. Our biomimetic pathway converts serine to cysteine by nitrile-activated dehydroalanine synthesis. We also demonstrate that N-acylcysteines catalyze peptide ligation, directly coupling kinetically stable-but energy-rich-α-amidonitriles to proteinogenic amines. This rare example of selective and efficient organocatalysis in water implicates cysteine as both catalyst and precursor in prebiotic peptide synthesis.
Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
Comment in
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Enhancing host cell infection by SARS-CoV-2.Science. 2020 Nov 13;370(6518):765-766. doi: 10.1126/science.abf0732. Science. 2020. PMID: 33184193 No abstract available.
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Peptide synthesis at the origin of life.Science. 2020 Nov 13;370(6518):767-768. doi: 10.1126/science.abf1698. Science. 2020. PMID: 33184194 No abstract available.
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