Studies on chitin: I. Enzymic degradation of chitin and chitin esters

Abstract

A study has been made of the enzymic degradation of chitin and the sodium salt of chitin sulphuric acid by a chitinase prepared from the intestinal tract of the snail, Helix aspersa. It is shown that, in a citrate-phosphate buffer, the pH for optimum activity is 4.8 for both substrates. Chitin, prepared from both lobster cuticle and fly puparia, is broken down by snail chitinase to N-acetylo- glucosamine, although there is also a trace of o-glucosamine. The sodium salt of chitin sulphuric acid also breaks down to N-acetyl-D-glucosamine and o-glucosamine. In both cases N-acetyl-D-glucosamine was isolated. The chitinase is without action on chitin nitrate. Acid hydrolysis of both chitin nitrate and the sodium salt of chitin sulphuric acid leads to the formation of o-glucosamine, which has been isolated as 2-hydroxynaphthylidene glucosamine. All attempts to phosphorylate chitin were unsuccessful. The structure of chitin is discussed. © 1954 CSIRO. All rights reserved.