Reaction: 2-amino-2-deoxy-D-gluconate = 2-dehydro-3-deoxy-D-gluconate + NH3 (overall reaction)
(1a) 2-amino-2-deoxy-D-gluconate = (2Z,4S,5R)-2-amino-4,5,6-trihydroxyhex-2-enoate + H2O
(1b) (2Z,4S,5R)-2-amino-4,5,6-trihydroxyhex-2-enoate = (4S,5R)-4,5,6-trihydroxy-2-iminohexanoate (spontaneous)
(1c) (4S,5R)-4,5,6-trihydroxy-2-iminohexanoate + H2O = 2-dehydro-3-deoxy-D-gluconate + NH3 (spontaneous)
Glossary: 2-amino-2-deoxy-D-gluconate = glucosaminate
Other name(s): glucosaminic dehydrase; D-glucosaminate dehydratase; D-glucosaminic acid dehydrase; aminodeoxygluconate dehydratase; 2-amino-2-deoxy-D-gluconate hydro-lyase (deaminating); aminodeoxygluconate ammonia-lyase; 2-amino-2-deoxy-D-gluconate ammonia-lyase; D-glucosaminate ammonia-lyase
Systematic name: D-glucosaminate ammonia-lyase (isomerizing; 2-dehydro-3-deoxy-D-gluconate-forming)
Comments: Contains pyridoxal phosphate. The enzyme releases an unstable enamine product that tautomerizes to an imine form, which undergoes spontaneous hydrolytic deamination to form the final product.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37290-91-8
1. Imanaga, Y. Metabolism of D-glucosamine. III. Enzymic degradation of D-glucosaminic acid. J. Biochem. (Tokyo) 45 (1958) 647-650.
2. Merrick, J.M. and Roseman, S. D-Glucosaminic acid dehydrase. Methods Enzymol. 9 (1966) 657-660.
3. Iwamoto, R., Imanaga, Y. and Soda, K. D-Glucosaminate dehydratase from Agrobacterium radiobacter. Physicochemical and enzymological properties. J. Biochem. (Tokyo) 91 (1982) 283-289. [PMID: 7068563]
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