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Polyamino acids as synthetic enzymes: mechanism, applications and relevance to prebiotic catalysis

2005; Elsevier BV; Volume: 23; Issue: 10 Linguagem: Inglês

10.1016/j.tibtech.2005.07.010

0167-9430

Giacomo Carrea, Stefano Colonna, David R. Kelly, Antonio Lazcano, Gianluca Ottolina, Stanley M. Roberts,

Enzyme Catalysis and Immobilization

Polyamino acids, such as polyleucine, behave as synthetic enzymes in the asymmetric epoxidation of chalcone and other electron-deficient alkenes (the Julià-Colonna reaction). The influences of reaction conditions, of the molecular structure of the catalysts and of the scaling-up of the process on the enantioselectivity of the reaction have been determined. The kinetics and mechanism have been investigated using a soluble PEG-polyleucine conjugate, which behaves in a similar way to an enzyme, showing saturation kinetics for both chalcone and HOO-. Enantioselective catalysis is achieved with peptides with as few as five residues and scalemic catalysts show high chiral amplification. Here, we discuss the relevance of these-enzyme like catalysts to prebiotic processes, such as the role of small peptides in the formation of optically active cyanohydrins.