Alcohol dehydrogenase, substrates

Fig. 30. Horse liver alcohol dehydrogenase substrate binding pocket, unoccupied. Stereo drawing from the work of Branden and colleagues. 

Scheme 1.1 Chiral fluorogenic alcohol dehydrogenase substrates and assay conditions.

Ramaswamy, S., M. el Ahmad, O. Danielsson, H. Jornvall and H. Eklund. Crystal structure of cod liver class I alcohol dehydrogenase substrate pocket and structurally variable segments. Protein Sci. 5 663-671, 1996. 

Alcohol dehydrogenase-catalyzed reduction of ketones is a convenient method for the production of chiral alcohols. HLAD, the most thoroughly studied enzyme, has a broad substrate specificity and accommodates a variety of substrates (Table 11). It efficiendy reduces all simple four- to nine-membered cycHc ketones and also symmetrical and racemic cis- and trans-decalindiones (167). Asymmetric reduction of aUphatic acycHc ketones (C-4—C-10) (103,104) can be efficiendy achieved by alcohol dehydrogenase isolated from Thermoanaerohium hrockii (TBADH) (168). The enzyme is remarkably stable at temperatures up to 85°C and exhibits high tolerance toward organic solvents. Alcohol dehydrogenases from horse Hver and T. hrockii... 

The leading substrate (A) is nicotinamide adenine dinucleotide (NAD ), and NAD and NADH (product Q) compete for a common site on E. A specific example is offered by alcohol dehydrogenase (ADH) ... 

As another example, studies with deuterium-labeled substrates have shown that the reaction of ethanol with the coenzyme NAD+ catalyzed by yeast alcohol dehydrogenase occurs with exclusive removal of the pro-R hydrogen from ethanol and with addition only to the Re face of NAD+. 

In addition to enzyme activity, the concentration of an nonelectroactive substrate can be determined electrochemically by this technique. By keeping the substrate (analyte) the limiting reagent, the amount of product produced is directly related to the initial concentration of substrate. Either kinetic or equilibrium measurements can be used. Typically an enzyme which produces NADH is used because NADH is readily detected electrochemically. Lactate has been detected using lactate dehydrogenase, and ethanol and methanol detected using alcohol dehydrogenase... 

Minteer and co-workers have also exploited the broad substrate specificity of PQQ-dependent alcohol dehydrogenase and aldehyde dehydrogenase from Gluconobacter species trapped within Nahon to oxidize either ethanol or glycerol at a fuel cell anode [Arechederra et al., 2007]. Although the alcohol dehydrogenase incorporates a series of heme electron transfer centers, it is unlikely that many enzyme molecules trapped within the mediator-free Nahon polymer are electronically engaged at the electrode. 

Oubrie A, Rozeboom HJ, Kalk KH, Huizinga EG, Dijkstra BW. 2002. Crystal structure of qui-nohemoprotein alcohol dehydrogenase from Comamonas testosteroni Structural basis for substrate oxidation and electron transfer. J Biol Chem 211 3727-3732. 

Yang, Y., Zhu, D., Piegat, T.J. and Hua, L. (2007) Enzymatic ketone reduction mapping the substrate profile of a short-chain alcohol dehydrogenase (YMR226c) from Saccharomyces cerevisiae. Tetrahedron Asymmetry, 18 (15), 1799-1803. 

Zhu, D., Malik, H.T. and Hua, L. (2006) Asymmetric ketone reduction by a hyperthermophilic alcohol dehydrogenase. The substrate specificity enantioselectivity and tolerance of organic solvents. Tetrahedron Asymmetry, 17 (21), 3010-3014. 

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