Effect of various acceptors on the rates of the cyclization and chain-shortening of amylose catalyzed by the cyclodextrin glycosyltransferase from Klebsiella pneumoniae M 5 al. Improvement of new photometric assay methods.

The effect of various acceptors on the cyclization and chain-shortening reaction of amylose catalyzed by cyclodextrin glycosyltransferase [(1 leads to 4)-alpha-D-glucan: [(1 leads to 4)-alpha-D-glycopyranosyl]transferase (cycling) EC 2.4.1.19] from Klebsiella pneumoniae M 5 al was studied by use of photometric-assay methods. The requirements for the acceptor were the same for both cyclization and chain-shortening, indicating the close relationship between both reactions. Maltose proved to be the most effective (2.48- and 5-fold acceleration of the cyclization and chain-shortening, respectively, in the presence of 584 micrometers maltose). The dependence of the chain-shortening reaction on the conformational state of the amylose molecules is discussed.