Accepted name: glutamin-(asparagin-)ase
Reaction: (1) L-glutamine + H2O = L-glutamate + NH3
(2) L-asparagine + H2O = L-aspartate + NH3
Other name(s): glutaminase-asparaginase; ansB (gene name); L-asparagine/L-glutamine amidohydrolase; L-ASNase/L-GLNase
Systematic name: L-glutamine(L-asparagine) amidohydrolase
Comments: The enzyme from the bacterium Achromobacter hydrolyses L-asparagine at 0.8 of the rate of L-glutamine; the D-isomers are also hydrolysed, but more slowly. cf. EC, glutaminase and EC, asparaginase.
1.  Roberts, J., Holcenberg, J.S. and Dolowy, W.C. Isolation, crystallization, and properties of Achromobacteraceae glutaminase-asparaginase with antitumor activity. J. Biol. Chem. 247 (1972) 84–90. [PMID: 5017769]
2.  Tanaka, S., Robinson, E.A., Appella, E., Miller, M., Ammon, H.L., Roberts, J., Weber, I.T. and Wlodawer, A. Structures of amidohydrolases. Amino acid sequence of a glutaminase-asparaginase from Acinetobacter glutaminasificans and preliminary crystallographic data for an asparaginase from Erwinia chrysanthemi. J. Biol. Chem. 263 (1988) 8583–8591. [PMID: 3379033]
3.  Lubkowski, J., Wlodawer, A., Ammon, H.L., Copeland, T.D. and Swain, A.L. Structural characterization of Pseudomonas 7A glutaminase-asparaginase. Biochemistry 33 (1994) 10257–10265. [PMID: 8068664]
4.  Ortlund, E., Lacount, M.W., Lewinski, K. and Lebioda, L. Reactions of Pseudomonas 7A glutaminase-asparaginase with diazo analogues of glutamine and asparagine result in unexpected covalent inhibitions and suggests an unusual catalytic triad Thr-Tyr-Glu. Biochemistry 39 (2000) 1199–1204. [PMID: 10684596]
[EC created 1976]