EC 18.104.22.168 - Exo-(1→4)-α-D-glucan lyase
IntEnz Enzyme Nomenclature
α-1,4-glucan 1,5-anhydro-D-fructose eliminase
- linear alpha-glucan = (n-1) 1,5-anhydro-D-fructose + D-glucose
The enzyme catalyses the sequential degradation of (1→4)-α-D-glucans from the non-reducing end with the release of 1,5-anhydro-D-fructose. Thus, for an α-glucan containing n (1→4)-linked glucose units, the final products are 1 glucose plus (n-1) 1,5-anhydro-D-fructose. Maltose, maltosaccharides and amylose are all completely degraded. It does not degrade (1→6)-α-glucosidic bonds and thus the degradation of a branched glucan, such as amylopectin or glycogen, will result in the formation of 1,5-anhydro-D-fructose plus a limit dextrin. Other enzymes involved in the anhydrofructose pathway are EC 22.214.171.124 (aldos-2-ulose dehydratase), EC 126.96.36.199 (1,5-anhydro-D-fructose dehydratase) and EC 188.8.131.52 (ascopyrone tautomerase).
Links to other databases
α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. I. Efficient purification and characterization from red seaweeds.Biochim. Biophys. Acta 1156 : 313-320 (1993). [PMID: 8461323]
α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. II. Subcellular localization and partial amino-acid sequence.Planta 191 : 137-142 (1993).
α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. III. Substrate specificity, mode of action, and cleavage mechanism.Biochim. Biophys. Acta 1244 : 1-9 (1995). [PMID: 7766642]
Efficient purification, characterization and partial amino acid sequencing of two α-1,4-glucan lyases from fungi.Biochim. Biophys. Acta 1339 : 311-320 (1997). [PMID: 9187252]
α-1,4-glucan lyases producing 1,5-anhydro-D-fructose from starch and glycogen have sequence similarity to α-glucosidases.Biochim. Biophys. Acta 1433 : 1-15 (1999). [PMID: 10446355]
α-1,4-Glucan lyase performs a trans-elimination via a nucleophilic displacement followed by a syn-elimination.J. Am. Chem. Soc. 124 : 4948-4949 (2002). [PMID: 11982345]
Detailed dissection of a new mechanism for glycoside cleavage: α-1,4-glucan lyase.Biochemistry 42 : 13081-13090 (2003). [PMID: 14596624]
[EC 184.108.40.206 created 1999]