Enzymatic polymerization to an alternating N-L-cysteinyl chitin derivative: a novel class of multivalent glycopeptidomimetics.

A novel chitin derivative with an alternating N-L-cysteinyl group was successfully prepared. The precursor chitin derivative with an alternating N-L-thioprolinyl group could be obtained via chitinase-catalyzed polymerization of the N'-L-thioprolinyl chitobiose oxazoline derivative as a transition state analog substrate monomer under weak alkaline conditions. Conversion of the L-thioprolinyl group to an L-cysteinyl group in the product chitin derivative proceeded in a dose-dependent manner by methoxyamine hydrochloride, and the reaction could be completed almost quantitatively. The obtained chitin derivative is a uniformly amino acid-branching polysaccharide, which is categorized into a novel class of multivalent glycopeptidomimetics.