A-1,4 Glucan lyase

S. Yu, T. Ahmad, L. Kenne, and M. Pedersen, a-1,4-Glucan lyase, a new class of starch glycogen degrading enzyme. 3. Substrate specificity, mode of action, and cleavage mechanism, BBA General Subjects, 1244 (1995) 1-9. 

Scheme 5 Proposed mechanism of the Gracilariopsis a-1,4-glucan lyase from GH31...

Red algae enzymes in the starch degradation pathway (e.g., a-1,4-glucan lyase and others)... 

Fig. 9. Proposed a(1 4)-glucan lyase mechanism. Breakdown of the covalent enz5mie intermediate may occur by direct rearrangement of the departing carboxylate amino acid side chain, or with the assistance of an alternate general base catal3rtic residue.

S. Yu, K. Bojsen, B. Svensson, and J. Marcussen, a-l,4-Glucan lyases producing 1,5-anhydro-D-fructose from starch and glycogen have sequence similarity to a-glucosidases, BBA Protein Struct. Mol. Enzym., 1433 (1999) 1-15, review, 53 references. 

SCHEME 1. Action of a-(l 4)-glucan lyase on floridean starch (the monosaccharide derivatives, which are split from the nonreducing ends of the polysaccharide chains probably in the form of 2-hydroxyglucal, are tautomerized to the more stable 1,5-anhydro-D-fructose, 5). 

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