Prebiotic synthesis of cysteine peptides that catalyze peptide ligation in neutral water.
Science
; 370(6518): 865-869, 2020 11 13.
Article
em En
| MEDLINE
| ID: mdl-33184216
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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
/
Cisteína
/
Origem da Vida
/
Nitrilas
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article