The Synthesis and Properties of Block-Copoly(amino acid)s with Folded Structures: A Primitive Enzyme Model

As a model of a primitive enzyme block-copoly(amino acid)s con taining L-serine and L-aspartic acid as the repeat unit were prepared. Spectro scopic measurements indicate that some block-copoly(amino acid)s, especially ABAB and ABABA types, do form folded conformations. Hydrolysis reactions of p-nitrophenyl p-guanidinobenzoate were accelerated in the presence of ABAB and ABABA type block-copoly(amino acid)s compared with a random copoly (amino acid). From these results we speculate that primitive enzymes were born by assembling block-copoly(amino acid)s.