Linked Life Data

9461252

Source:http://linkedlifedata.com/resource/pubmed/id/9461252

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-3-5
pubmed:abstractText
The effect of the physical state of low density lipoprotein (LDL) core and the selectivity of the degradation of LDL cholesterol esters (CEs) by the lysosomal acid lipase (LAL) in vitro were investigated. The physical state of LDL was modulated by varying temperature or the triglyceride content of the core. Normal LDL showed an abrupt increase of CE hydrolysis at 24 degrees C and another deviation occurred close to 36 degrees C. 1H-NMR measurements showed that these temperatures coincide with the onset and end temperatures of the LDL core lipid transition, respectively. Enrichment of LDL with triglycerides abolished the abrupt changes both in the CE hydrolysis and in the physical state of LDL lipids. These findings show that there is a correlation between the physical state of LDL lipids and the rate of LAL-mediated hydrolysis of the CEs in the particle. The relative rates of hydrolysis of different CE species were also compared. With native LDL, increasing the length of a saturated acyl chain from 14 to 20 carbons reduced the rate of degradation of CE modestly, while increasing acyl chain unsaturation increased the rate of degradation markedly. However, cholesterol oleate was hydrolyzed more slowly than cholesterol stearate. Essentially the same order of hydrolytic susceptibility was observed when the CE species were incorporated into triglyceride-enriched LDL, reconstituted high density lipoprotein particles or in detergent/phospholipid micelles. These results indicate that the selective hydrolysis of CE species in LDL is determined mainly by the ease with which the CE molecule can emerge from the surface layer reach the active site of LAL. Slower degradation of the more saturated CEs by LAL could lead, under certain conditions, to their accumulation in lysosomes and eventually, to cell death, lysis and deposition of crystalline, poorly mobilizable lipids to the arterial intima.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
1389
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
112-22
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Degradation of low density lipoprotein cholesterol esters by lysosomal lipase in vitro. Effect of core physical state and basis of species selectivity.
pubmed:affiliation
Institute of Biomedicine, Department of Medical Chemistry, University of Helsinki, Finland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't