Mobility of Fluorobenzyl Alcohols Bound to Liver Alcohol Dehydrogenases as Determined by NMR and X-ray Crystallographic StudiesRubach, J.K., Plapp, B.V.
(2002) Biochemistry 41: 15770-15779
- PubMed: 12501206
- Primary Citation of Related Structures:  1MGO
- PubMed Abstract:
- BINDING OF SUBSTRATE IN A TERNARY COMPLEX OF HORSE LIVER ALCOHOL DEHYDROGENASE
Eklund, H.,Plapp, B.V.,Samama, J.P.,Branden, C.I.
(1982) J.Biol.Chem. 257: 14349
- Structures of Horse Liver Alcohol Dehydrogenase Complexed with NAD+ and Substituted Benzyl Alcohols
Ramaswamy, S.,Eklund, H.,Plapp, B.V.
(1994) Biochemistry 33: 5230
- STRUCTURE OF A TRICLINIC TERNARY COMPLEX OF HORSE LIVER ALCOHOL DEHYDROGENASE AT 2.9 A RESOLUTION
Eklund, H.,Samma, J.P.,Wallen, L.,Branden, C.I.,Akeson, A.,Jones, T.A.
(1981) J.Mol.Biol. 146: 561
- THREE-DIMENSIONAL STRUCTURE OF HORSE LIVER ALCOHOL DEHYDROGENASE AT 2-4 ANGSTROMS RESOLUTION
Eklund, H.,Nordstrom, B.,Zeppezauer, E.,Soderlund, G.,Ohlsson, I.,Boiwe, T.,Soderberg, B.O.,Tapia, O.,Branden, C.I.,Akeson, A.
(1976) J.Mol.Biol. 102: 27
The relationship between substrate mobility and catalysis was studied with wild-type and Phe93Ala (F93A) horse liver alcohol dehydrogenase (ADH). Wild-type ADH binds 2,3,4,5,6-pentafluorobenzyl alcohol in one position as shown by X-ray results, and ( ...
The relationship between substrate mobility and catalysis was studied with wild-type and Phe93Ala (F93A) horse liver alcohol dehydrogenase (ADH). Wild-type ADH binds 2,3,4,5,6-pentafluorobenzyl alcohol in one position as shown by X-ray results, and (19)F NMR shows five resonances for the fluorines of the bound alcohol. The two meta-fluorines exchange positions with a rate constant of about 4 s(-1), indicating that mobility (ring flipping) of the benzyl alcohol is relatively restricted. The wild-type enzyme binds 2,3-difluorobenzyl alcohol in two alternative conformations that are related by a ring flip and a small translation of the fluorinated benzene ring, and the (19)F NMR spectrum shows three resonances for the two bound fluorines, consistent with the two orientations. Phe-93 interacts with the bound benzyl alcohols, and the F93A substitution decreases the rate constants for hydride transfer for benzyl alcohol oxidation and benzaldehyde reduction by 7.4- and 130-fold, respectively. The structure of F93A ADH crystallized with NAD(+) and 2,3,4,5,6-pentafluorobenzyl alcohol is similar to the structure of the wild-type enzyme complex except that the pentafluorobenzyl alcohol is not found in one position. The (19)F NMR spectrum of the F93A ADH-NAD(+)-pentafluorobenzyl alcohol complex shows three resonances for the bound fluorines. Line shape analysis of the spectrum suggests the bound pentafluorobenzyl ring undergoes rapid ring-flipping at about 20 000 s(-1). The F93A substitution greatly increases the mobility of the benzyl alcohol but modestly and differentially decreases the probability that the substrate is preorganized for hydride transfer.
Department of Biochemistry, The University of Iowa, Iowa City, IA 52242, USA.