Linked Life Data

7744831

Source:http://linkedlifedata.com/resource/pubmed/id/7744831

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
1995-6-12
pubmed:abstractText
In the present study, lecithin-cholesterol acyltransferase (LCAT) catalyzed esterification of oxysterols was investigated by using discoidal bilayer particles (DBP) containing various oxysterols, phosphatidylcholines, and apolipoprotein A-I. The esterified oxysterols were analyzed by high pressure liquid chromatography, gas chromatography, and mass spectrometry. LCAT esterified all oxysterols tested that are known to be present in human plasma. The esterification yields in almost all cases were relatively high, often as high as the yield of cholesterol esterification. When DBP preparations containing 27-hydroxycholesterol and various phosphatidylcholines were used for the LCAT reaction, both monoesters and diesters were produced. The mass spectrometry analysis showed that the monoester was produced by the esterification of the 3 beta-hydroxyl group and not the 27-hydroxyl group. The diesters were apparently produced by the esterification of the 27-hydroxyl group only after the esterification of the 3 beta-hydroxyl group. Phosphatidylcholine containing a saturated acyl group at sn-1 position and an unsaturated acyl group at sn-2 position gave generally high esterification yield. The esterification of various oxysterols was compared by using DBP containing dioleoyl-phosphatidylcholine and individual oxysterols. All oxysterols produced 3 beta-oleoyl monoesters. Unlike 27-hydroxycholesterol, 25-hydroxycholesterol, 7 alpha-hydroxycholesterol, 7 beta-hydroxycholesterol, or cholestanetriol did not produce diesters. Various factors influencing the formation of the monoesters and diesters from 27-hydroxycholesterol were investigated. When dioleoyl-phosphatidylcholine was used as the acyl donor, prolonged dialysis of DBP preparations and increase in the ratio of the enzyme concentration to substrate particle concentration increased the diester formation. Significant amounts of diesters were also produced by using 1-palmitoyl-2-oleoyl-phosphatidylcholine and other phosphatidylcholines as the acyl donors. By analyzing the conditions of monoester and diester formation, a scheme for the LCAT reaction pathway was proposed.
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
19
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11812-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Esterification of oxysterols by human plasma lecithin-cholesterol acyltransferase.
pubmed:affiliation
Burnsides Research Laboratory, Department of Food Science, University of Illinois, Urbana 61801, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't