Oxygenation cascade in conversion of n-alkanes to alpha,omega-dioic acids catalyzed by cytochrome P450 52A3

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Item Type:	Article
Title:	Oxygenation cascade in conversion of n-alkanes to alpha,omega-dioic acids catalyzed by cytochrome P450 52A3
Creators Name:	Scheller, U., Zimmer, T., Becher, D., Schauer, F. and Schunck, W.H.
Abstract:	Purified recombinant cytochrome P450 52A3 and the corresponding NADPH-cytochrome P450 reductase from the alkane-assimilating yeast Candida maltosa were reconstituted into an active alkane monooxygenase system. Besides the primary product, 1-hexadecanol, the conversion of hexadecane yielded up to five additional metabolites, which were identified by gas chromatography-electron impact mass spectrometry as hexadecanal, hexadecanoic acid, 1, 16-hexadecanediol, 16-hydroxyhexadecanoic acid, and 1, 16-hexadecanedioic acid. As shown by substrate binding studies, the final product 1,16-hexadecanedioic acid acts as a competitive inhibitor of n-alkane binding and may be important for the metabolic regulation of the P450 activity. Kinetic studies of the individual sequential reactions revealed high Vmax values for the conversion of hexadecane, 1-hexadecanol, and hexadecanal (27, 23, and 69 min-1, respectively), whereas the oxidation of hexadecanoic acid, 1, 16-hexadecanediol, and 16-hydroxyhexadecanoic acid occurred at significantly lower rates (9, 9, and 5 min-1, respectively). 1-Hexadecanol was found to be the main branch point between mono- and diterminal oxidation. Taken together with data on the incorporation of 18O2-derived oxygen into the hexadecane oxidation products, the present study demonstrates that a single P450 form is able to efficiently catalyze a cascade of sequential mono- and diterminal monooxygenation reactions from n-alkanes to alpha, omega-dioic acids with high regioselectivity.
Keywords:	Alkanes, Catalysis, Cytochrome P-450 Enzyme System, Dicarboxylic Acids, Fungal Proteins, Gas Chromatography-Mass Spectrometry, Kinetics, Mixed Function Oxygenases, Oxygen
Source:	Journal of Biological Chemistry
ISSN:	0021-9258
Publisher:	American Society for Biochemistry and Molecular Biology
Volume:	273
Number:	49
Page Range:	32528-32534
Date:	4 December 1998
Official Publication:	https://doi.org/10.1074/jbc.273.49.32528
PubMed:	View item in PubMed

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