Abstract
Drosophila alcohol dehydrogenase (Adh) catalyses the oxidation of both alcohols and aldehydes. In the latter case, the oxidation is followed by a reduction of the aldehyde, i.e. a dismutation reaction. At high pH, dismutation is accompanied by a small release of NADH, which is not observed at neutral pH. Previously it has been emphasized that kinetic coefficients obtained by measuring the increase in A340, i.e. the release of NADH at high pH is not a direct measure of the aldehyde oxidation reaction and these values cannot be compared with those for alcohol dehydrogenation. In this article we demonstrate that this is not entirely true, and that the coefficients phiB and phiAB, where B is the aldehyde and A is NAD+, are the same for a dismutation reaction and a simple aldehyde dehydrogenase reaction. Thus the substrate specificity of the aldehyde oxidation reaction can be determined by simply measuring the NADH release. The coefficients for oxidation and dehydrogenation reactions (phi0d and phiAd respectively) are complex and involve the constants for the dismutation reaction. However, dead-end inhibitors can be used to determine the quantitative contribution of the kinetic constants for the aldehyde oxidation and reduction pathways to the phi0d and phiAd coefficients. The combination of dead-end and product inhibitors can be used to determine the reaction mechanism for the aldehyde oxidation pathway. Previously, we showed that with Drosophila Adh, the interconversion between alcohols and aldehydes followed a strictly compulsory ordered pathway, although aldehydes and ketones formed binary complexes with the enzyme. This raised the question regarding the reaction mechanism for the oxidation of aldehydes, i.e. whether a random ordered pathway was followed. In the present work, the mechanism for the oxidation of different aldehydes and the accompanying dismutation reaction with the slow alleloenzyme (AdhS) from Drosophila melanogaster has been studied. To obtain reliable results for the liberation of NADH during the initial-rate phase, the reaction was measured with a sensitive recording filter fluorimeter, and the complexes formed with the different dead-end and product inhibitors have been interpreted on the basis of a full dismutation reaction. The results are only consistent with a compulsory ordered reaction mechanism, with the formation of a dead-end binary enzyme-aldehyde complex. Under initial-velocity conditions, the rate of acetate release was calculated to be larger than 2.5 s-1, which is more than ten times that of NADH. The substrate specificity constant (kcat/Km or 1/phiB) with respect to the oxidation of substrates was propan-2-ol>ethanol>acetaldehyde>trimethylacetaldehyde.
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- CLELAND W. W. The kinetics of enzyme-catalyzed reactions with two or more substrates or products. I. Nomenclature and rate equations. Biochim Biophys Acta. 1963 Jan 8;67:104–137. doi: 10.1016/0006-3002(63)91800-6. [DOI] [PubMed] [Google Scholar]
- CLELAND W. W. The kinetics of enzyme-catalyzed reactions with two or more substrates or products. II. Inhibition: nomenclature and theory. Biochim Biophys Acta. 1963 Feb 12;67:173–187. doi: 10.1016/0006-3002(63)91815-8. [DOI] [PubMed] [Google Scholar]
- Chambers G. K. Gene expression, adaptation and evolution in higher organisms. Evidence from studies of Drosophila alcohol dehydrogenases. Comp Biochem Physiol B. 1991;99(4):723–730. doi: 10.1016/0305-0491(91)90135-z. [DOI] [PubMed] [Google Scholar]
- Chen Z., Jiang J. C., Lin Z. G., Lee W. R., Baker M. E., Chang S. H. Site-specific mutagenesis of Drosophila alcohol dehydrogenase: evidence for involvement of tyrosine-152 and lysine-156 in catalysis. Biochemistry. 1993 Apr 6;32(13):3342–3346. doi: 10.1021/bi00064a017. [DOI] [PubMed] [Google Scholar]
- Chen Z., Lu L., Shirley M., Lee W. R., Chang S. H. Site-directed mutagenesis of glycine-14 and two "critical" cysteinyl residues in Drosophila alcohol dehydrogenase. Biochemistry. 1990 Feb 6;29(5):1112–1118. doi: 10.1021/bi00457a003. [DOI] [PubMed] [Google Scholar]
- Cols N., Marfany G., Atrian S., Gonzàlez-Duarte R. Effect of site-directed mutagenesis on conserved positions of Drosophila alcohol dehydrogenase. FEBS Lett. 1993 Mar 15;319(1-2):90–94. doi: 10.1016/0014-5793(93)80043-t. [DOI] [PubMed] [Google Scholar]
- Dalziel K., Dickinson F. M. Aldehyde mutase. Nature. 1965 Apr 17;206(981):255–257. doi: 10.1038/206255a0. [DOI] [PubMed] [Google Scholar]
- Eisses K. T., Schoonen W. G., Aben W., Scharloo W., Thörig G. E. Dual function of the alcohol dehydrogenase of Drosophila melanogaster: ethanol and acetaldehyde oxidation by two allozymes ADH-71k and ADH-F. Mol Gen Genet. 1985;199(1):76–81. doi: 10.1007/BF00327513. [DOI] [PubMed] [Google Scholar]
- Heinstra P. W., Geer B. W., Seykens D., Langevin M. The metabolism of ethanol-derived acetaldehyde by alcohol dehydrogenase (EC 1.1.1.1) and aldehyde dehydrogenase (EC 1.2.1.3) in Drosophila melanogaster larvae. Biochem J. 1989 May 1;259(3):791–797. doi: 10.1042/bj2590791. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Henehan G. T., Chang S. H., Oppenheimer N. J. Aldehyde dehydrogenase activity of Drosophila melanogaster alcohol dehydrogenase: burst kinetics at high pH and aldehyde dismutase activity at physiological pH. Biochemistry. 1995 Sep 26;34(38):12294–12301. doi: 10.1021/bi00038a025. [DOI] [PubMed] [Google Scholar]
- Hinson J. A., Neal R. A. An examination of the oxidation of aldehydes by horse liver alcohol dehydrogenase. J Biol Chem. 1972 Nov 10;247(21):7106–7107. [PubMed] [Google Scholar]
- Jörnvall H., Persson B., Krook M., Kaiser R. Alcohol dehydrogenases. Biochem Soc Trans. 1990 Apr;18(2):169–171. doi: 10.1042/bst0180169. [DOI] [PubMed] [Google Scholar]
- Jörnvall H., Persson M., Jeffery J. Alcohol and polyol dehydrogenases are both divided into two protein types, and structural properties cross-relate the different enzyme activities within each type. Proc Natl Acad Sci U S A. 1981 Jul;78(7):4226–4230. doi: 10.1073/pnas.78.7.4226. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McKinley-McKee J. S., Winberg J. O., Pettersson G. Mechanism of action of Drosophila melanogaster alcohol dehydrogenase. Biochem Int. 1991 Dec;25(5):879–885. [PubMed] [Google Scholar]
- Olson L. P., Luo J., Almarsson O., Bruice T. C. Mechanism of aldehyde oxidation catalyzed by horse liver alcohol dehydrogenase. Biochemistry. 1996 Jul 30;35(30):9782–9791. doi: 10.1021/bi952020x. [DOI] [PubMed] [Google Scholar]
- Thatcher D. R., Sawyer L. Secondary-structure prediction from the sequence of Drosophila melanogaster (fruitfly) alcohol dehydrogenase. Biochem J. 1980 Jun 1;187(3):884–886. doi: 10.1042/bj1870884. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winberg J. O., Hovik R., McKinley-McKee J. S., Juan E., Gonzalez-Duarte R. Biochemical properties of alcohol dehydrogenase from Drosophila lebanonensis. Biochem J. 1986 Apr 15;235(2):481–490. doi: 10.1042/bj2350481. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winberg J. O., Hovik R., McKinley-McKee J. S. The alcohol dehydrogenase alleloenzymes AdhS and AdhF from the fruitfly Drosophila melanogaster: an enzymatic rate assay to determine the active-site concentration. Biochem Genet. 1985 Apr;23(3-4):205–216. doi: 10.1007/BF00504319. [DOI] [PubMed] [Google Scholar]
- Winberg J. O., McKinley-McKee J. S. Drosophila melanogaster alcohol dehydrogenase. Biochemical properties of the NAD+-plus-acetone-induced isoenzyme conversion. Biochem J. 1988 Apr 1;251(1):223–227. doi: 10.1042/bj2510223. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winberg J. O., McKinley-McKee J. S. Drosophila melanogaster alcohol dehydrogenase: product-inhibition studies. Biochem J. 1994 Aug 1;301(Pt 3):901–909. doi: 10.1042/bj3010901. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winberg J. O., McKinley-McKee J. S. Kinetic interpretations of active site topologies and residue exchanges in Drosophila alcohol dehydrogenases. Int J Biochem. 1992 Feb;24(2):169–181. doi: 10.1016/0020-711x(92)90245-v. [DOI] [PubMed] [Google Scholar]
- Winberg J. O., McKinley-McKee J. S. The AdhS alleloenzyme of alcohol dehydrogenase from Drosophila melanogaster. Variation of kinetic parameters with pH. Biochem J. 1988 Oct 15;255(2):589–599. [PMC free article] [PubMed] [Google Scholar]
- Winberg J. O., Thatcher D. R., McKinley-McKee J. S. Alcohol dehydrogenase from the fruitfly Drosophila melanogaster. Inhibition studies of the alleloenzymes AdhS and AdhUF. Biochim Biophys Acta. 1982 May 21;704(1):17–25. doi: 10.1016/0167-4838(82)90126-1. [DOI] [PubMed] [Google Scholar]