Horse Liver Alcohol Dehydrogenase: Zinc Coordination and Catalysis.Plapp, B.V., Savarimuthu, B.R., Ferraro, D.J., Rubach, J.K., Brown, E.N., Ramaswamy, S.
(2017) Biochemistry 56: 3632-3646
- PubMed: 28640600
- DOI: 10.1021/acs.biochem.7b00446
- Primary Citation of Related Structures:
- PubMed Abstract:
- Binding of formamides to liver alcohol dehydrogenase.
Ramaswamy, S.,Scholze, M.,Plapp, B.V.
(1997) Biochemistry 36: 3522
- Formamides mimic aldehydes and inhibit liver alcohol dehydrogenases and ethanol metabolism.
Venkataramaiah, T.H.,Plapp, B.V.
(2003) J. Biol. Chem. 278: 36699
- Flexibility of liver alcohol dehydrogenase in stereoselective binding of 3-butylthiolane 1-oxides.
Cho, H.,Ramaswamy, S.,Plapp, B.V.
(1997) Biochemistry 36: 382
- Atomic-resolution structures of horse liver alcohol dehydrogenase with NAD(+) and fluoroalcohols define strained Michaelis complexes.
Plapp, B.V.,Ramaswamy, S.
(2012) Biochemistry 51: 4035
During catalysis by liver alcohol dehydrogenase (ADH), a water bound to the catalytic zinc is replaced by the oxygen of the substrates. The mechanism might involve a pentacoordinated zinc or a double-displacement reaction with participation by a near ...
During catalysis by liver alcohol dehydrogenase (ADH), a water bound to the catalytic zinc is replaced by the oxygen of the substrates. The mechanism might involve a pentacoordinated zinc or a double-displacement reaction with participation by a nearby glutamate residue, as suggested by studies of human ADH3, yeast ADH1, and some other tetrameric ADHs. Zinc coordination and participation of water in the enzyme mechanism were investigated by X-ray crystallography. The apoenzyme and its complex with adenosine 5'-diphosphoribose have an open protein conformation with the catalytic zinc in one position, tetracoordinated by Cys-46, His-67, Cys-174, and a water molecule. The bidentate chelators 2,2'-bipyridine and 1,10-phenanthroline displace the water and form a pentacoordinated zinc. The enzyme-NADH complex has a closed conformation similar to that of ternary complexes with coenzyme and substrate analogues; the coordination of the catalytic zinc is similar to that found in the apoenzyme, except that a minor, alternative position for the catalytic zinc is ∼1.3 Å from the major position and closer to Glu-68, which could form the alternative coordination to the catalytic zinc. Complexes with NADH and N-1-methylhexylformamide or N-benzylformamide (or with NAD+ and fluoro alcohols) have the classical tetracoordinated zinc, and no water is bound to the zinc or the nicotinamide rings. The major forms of the enzyme in the mechanism have a tetracoordinated zinc, where the carboxylate group of Glu-68 could participate in the exchange of water and substrates on the zinc. Hydride transfer in the Michaelis complexes does not involve a nearby water.
Department of Biochemistry, The University of Iowa , Iowa City, Iowa 52242, United States.