Identification for the monomer joint-mode of biosynthesised polylysine by salicylaldehyde protection

A novel method was established to efficiently and conveniently identify the structure of polylysine which produced by microbial fermentation.Free amino groups of polylysine were protected by salicylaldehyde to form Schiff base.The C=N bond of Schiffbase was reduced by NaBH 4 to form C N bond.The reduced products were hydrolyzed under acidic condition.Then the hydrolyzed products were analyzed by TLC.The structure of polylysine made by biosynthesis was proved to be linked by the e amide bond.This method could also be used to analysis of N terminal amino acid of protein or polypeptides.