Linked Life Data

7228857

Source:http://linkedlifedata.com/resource/pubmed/id/7228857

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1981-7-20
pubmed:abstractText
Methyl sterol oxidase of microsomal synthesis of cholesterol from lanosterol is a mixed-function oxidase that is dependent upon reduced pyridine nucleotide. The methyl sterol oxidase, as well as NADH-cytochrome c reductase, in intact rat liver microsomes are inhibited by anti-cytochrome b5 immunoglobulin, but NADPH-cytochrome c reductase is not affected. There is a decreased time lag prior to onset of reoxidation of steady state levels of reduced cytochrome b5 when 4-methyl sterol oxidase substrates are present. Trypsin treatment of microsomes destroys cytochrome b5 with loss of methyl sterol oxidase activity. Activity is restored by addition of purified cytochrome b5 to trypsin-treated microsomes. Initial attempts to solubilize and purify 4-methyl sterol oxidase have been only partially successful due to the extreme lability of the oxidase. However, DEAE-cellulose column chromatography of a detergent extract of microsomes yields a fraction that contains the oxidase, lipids, and NADH-cytochrome b5 reductase but is free of cytochrome b5. Oxidation of 4 alpha [30-3H] methyl-5 alpha-cholest-7-en-3 beta-ol by methyl sterol oxidase in this isolated fraction can be fully restored by the addition of purified liver microsomal cytochrome b5. These results strongly support the suggestion that membrane-bound cytochrome b5 of rat liver microsomes is an obligatory electron carrier from NADH to 4-methyl sterol oxidase.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
256
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4822-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Total enzymic synthesis of cholesterol from lanosterol. Cytochrome b5-dependence of 4-methyl sterol oxidase.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.