Linked Life Data

1536566

Source:http://linkedlifedata.com/resource/pubmed/id/1536566

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-3-24
pubmed:abstractText
Pig liver squalene epoxidase (SE) has been partially purified from solubilized microsomes by DEAE-Sephacel and Blue Sepharose 4B chromatography. This stable and reproducible preparation was used to investigate the mechanism of several substrate-like inhibitors of SE and to study the effects of pH, metals, detergents, and cofactors on enzyme activity. Most divalent (1 mM) and trivalent (0.1 mM) metal cations had little effect on SE at pH 7.4; only ferrous and cupric ions showed ca. 50% reduction in SE activity. Interestingly, at pH 8.8, EDTA (10 mM) shows 1.8-fold enhancement of enzyme activity. Among the detergents, Triton X-100 was clearly superior for solubilization and purification of porcine SE; Tween 80, Lubrol-PX, 3-[(3-cholamidopropyl)dimethylammonio]propanesulfonic acid, octyl beta-glucoside, and three different Zwittergents were much less effective for SE solubilization. Partially purified pig liver SE showed maximal activity at pH 8.8-9.0. Trisnorsqualene alcohol and trisnorsqualene cyclopropylamine were noncompetitive inhibitors at pH 8.8, with Ki values of 4 microM and 180 nM, respectively; these two inhibitors were not substrates for SE. In contrast, 26-hydroxysqualene was both a competitive inhibitor with a Ki value of 4 microM at pH 8.8 and a substrate for SE. An unexpected enhancement (up to 350%) of SE activity was observed at pH 7.4 following preincubation with selected nonpolar derivatives of farnesol and farnesoic acid. At pH 8.8, this effect was less dramatic but still evident.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:volume
293
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
305-13
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Inhibition and activation of porcine squalene epoxidase.
pubmed:affiliation
Department of Chemistry, State University of New York, Stony Brook 11794-3400.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't