Linked Life Data

8645001

Source:http://linkedlifedata.com/resource/pubmed/id/8645001

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-7-12
pubmed:databankReference
pubmed:abstractText
Two enzymes, P450 52A3 (P450Cm1) and 52A4 (P450Cm2), the genes of which belong to the CYP52 multigene family occurring in the alkane-assimilating yeast Candida maltosa, have been characterized biochemically and compared in terms of their substrate specificities. For this purpose, both the p450 proteins and the corresponding C. maltosa NADPH-cytochrome P450 reductase were separately produced by expressing their cDNAs in Saccharomyces cerevisiae, purified, and reconstituted to active monooxygenase systems. Starting from microsomal fractions with a specific content of 0.75 nmol P450Cm1, 0.34 nmol P450Cm2, and 10.5 units reductase per milligram of protein, respectively, each individual recombinant protein was purified to homogeneity. P450 substrate difference spectra indicated strong type I spectral changes and high-affinity binding of n-hexadecane (Ks= 26 micron) and n-octadecane (Ks = 27 microM) to P450Cm1, whereas preferential binding to P450Cm2 was observed using lauric acid (Ks = 127 microM) and myristic acid (Ks = 134 microM) as substrates. These substrate selectivities were further substantiated by kinetic parameters, determined for n-alkane and fatty acid hydroxylation in a reconstituted system, which was composed of the purified components and phospholipid, as well as in microsomes obtained after coexpressing each of the P450 proteins with the reductase. The highest catalytic activities within the reconstituted system were measured for n-hexadecane hydroxylation to 1-hexadecanol by P450Cm1 (Vmax = 27 microM x min-1, Km = 54 microM) and oxidation of lauric acid to 16-hydroxylauric acid by P450Cm2 (Vmax = 30 microM x min-1, Km = 61 microM). We conclude that P450Cm1 and P450Cm2 exhibit overlapping but distinct substrate specificities due to different chain-length dependencies and preferences for either n-alkanes or fatty acids.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
328
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
245-54
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8645001-Alkanes, pubmed-meshheading:8645001-Amino Acid Sequence, pubmed-meshheading:8645001-Candida, pubmed-meshheading:8645001-Cloning, Molecular, pubmed-meshheading:8645001-Cytochrome P-450 Enzyme System, pubmed-meshheading:8645001-DNA, Complementary, pubmed-meshheading:8645001-Fatty Acids, pubmed-meshheading:8645001-Fungal Proteins, pubmed-meshheading:8645001-Genes, Fungal, pubmed-meshheading:8645001-Hydroxylation, pubmed-meshheading:8645001-Kinetics, pubmed-meshheading:8645001-Microsomes, pubmed-meshheading:8645001-Mixed Function Oxygenases, pubmed-meshheading:8645001-Molecular Sequence Data, pubmed-meshheading:8645001-Multigene Family, pubmed-meshheading:8645001-Recombinant Proteins, pubmed-meshheading:8645001-Saccharomyces cerevisiae, pubmed-meshheading:8645001-Spectrophotometry, pubmed-meshheading:8645001-Substrate Specificity
pubmed:year
1996
pubmed:articleTitle
Characterization of the n-alkane and fatty acid hydroxylating cytochrome P450 forms 52A3 and 52A4.
pubmed:affiliation
Max-Delbrück-Center for Molecular Medicine, Berlin-Buch, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't