| Mechanistic study of an improbable reaction: alkene dehydrogenation by the delta12 acetylenase of Crepis alpina. | |
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MedLine Citation:
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PMID: 12940747 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The mechanism by which the fatty acid acetylenase of Crepis alpina catalyzes crepenynic acid ((9Z)-octadeca-9-en-12-ynoic acid) production from linoleic acid has been probed through the use of kinetic isotope effect (KIE) measurements. This was accomplished by incubating appropriate mixtures of regiospecifically deuterated isotopomers with a strain of Saccharomyces cerevisiae expressing a functional acetylenase. LC/MS analysis of crepenynic acid obtained in these experiments showed that the oxidation of linoleate occurs in two discrete steps, since the cleavage of the C12-H bond is very sensitive to isotopic substitution (k(H)/k(D) = 14.6 +/- 3.0) while a minimal isotope effect (k(H)/k(D) = 1.25 +/- 0.08) was observed for the C13-H bond breaking step. These data suggest that crepenynic acid is produced via initial H-atom abstraction at C12 of a linoleoyl substrate. The relationship between the mechanism of enzymatic acetylenation and epoxidation is discussed. |
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Authors:
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Darwin W Reed; Devin R Polichuk; Peter H Buist; Stephen J Ambrose; Robert J Sasata; Christopher K Savile; Andrew R S Ross; Patrick S Covello |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of the American Chemical Society Volume: 125 ISSN: 0002-7863 ISO Abbreviation: J. Am. Chem. Soc. Publication Date: 2003 Sep |
Date Detail:
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Created Date: 2003-08-27 Completed Date: 2003-10-21 Revised Date: 2009-11-19 |
Medline Journal Info:
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Nlm Unique ID: 7503056 Medline TA: J Am Chem Soc Country: United States |
Other Details:
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Languages: eng Pagination: 10635-40 Citation Subset: IM |
Affiliation:
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NRC Plant Biotechnology Institute, 110 Gymnasium Place, Saskatoon, Saskatchewan, Canada S7N 0W9. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Alkenes
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chemistry,
metabolism* Alkynes / chemistry, metabolism Crepis / enzymology* Fatty Acid Desaturases / chemistry, metabolism* Hydrogenation Kinetics Linoleic Acids / chemistry, metabolism |
| Chemical | |
Reg. No./Substance:
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0/Alkenes; 0/Alkynes; 0/Linoleic Acids; EC 1.14.19.-/Fatty Acid Desaturases; EC 1.14.99.-/acetylenase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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