The reduction of allyl alcohols by Clostridium species is catalyzed by the combined action of alcohol dehydrogenase and enoate reductase
| Autor: | Maria-Anna Kim, Helmut Simon, Johann Bader |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Oxidoreductases Acting on CH-CH Group Donors
Hydrogenase Stereochemistry Propanols 1-Propanol Reductase Biochemistry Substrate Specificity chemistry.chemical_compound Clostridium Stereospecificity Organic chemistry Alcohol dehydrogenase Ethanol biology Chemistry Clostridium kluyveri biology.organism_classification NAD Alcohol Oxidoreductases Kinetics biology.protein Fatty Acids Unsaturated NAD+ kinase Oxidoreductases Oxidation-Reduction NADP |
| Zdroj: | Hoppe-Seyler's Zeitschrift fur physiologische Chemie. 362(6) |
| ISSN: | 0018-4888 |
| Popis: | Cells, as well as crude extracts of Clostridium kluyveri or Clostridium spec. La 1, catalyze the hydrogenation of (E)- or (Z)-2-butenol to n-butanol. No single enzyme could be detected which directly accomplishes this reaction. It turned out that the reduction occurs as follows: 2-butenol leads to 2-butenal leads to n-butanal leads to n-butanol. The first step is catalyzed by the NAD-dependent alcohol dehydrogenase in C. kluyveri, the second by the recently detected enoate reductase which reduces not only nonactivated alpha, beta-unsaturated acylates but also alpha, beta-unsaturated aldehydes in a NADH-dependent reaction and the third step is again catalyzed by alcohol dehydrogenase. In Clostridium La 1 the alcohol dehydrogenase is NADP-dependent. The rate of the reduction of 2-butenol to n-butanol depends not only on the enzymes, but also on the ratio NAD(P)/NAD(P)H. In the presence of methylviologen cation radical which is formed by the reduction of methylviologen by the system H2/hydrogenase, the ratio NAD(P)/NAD(P)H is too small for the dehydrogenation of 2-butenol to 2-butenal. This explains the antagonistic effect of methylviologen in the hydrogenation of allyl alcohols and 2-enoates by both Clostridium species. Furthermore, the mechanism explains the finding that from a preparative point of view ethanol is a better electron donor than hydrogen for the stereospecific reduction of allyl alcohols. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|