MISC

2000年7月19日

Inhibition of lipoprotein lipase activity by sphingomyelin: Role of membrane surface structure

Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
  • Hiroyuki Saito
  • ,
  • Itaru Arimoto
  • ,
  • Masafumi Tanaka
  • ,
  • Tetsuya Sasaki
  • ,
  • Tsuyoshi Tanimoto
  • ,
  • Satoshi Okada
  • ,
  • Tetsurou Handa

1486
2-3
開始ページ
312
終了ページ
320
記述言語
英語
掲載種別
DOI
10.1016/S1388-1981(00)00071-8

We have recently shown that sphingomyelin (SM) strongly inhibits lipoprotein lipase (LPL)-mediated lipolysis in monolayers and emulsion particles. To further evaluate how SM modulates LPL activity on the emulsion surface, the relationship between membrane surface structure and LPL activity was investigated. We measured fluorescence anisotropy of 1-palmitoyl-2-[3- (diphenylhexatrienyl)propionyl]-sn-3-phosphatidylcholine, probing surface acyl chain fluidity, and fluorescence lifetime of N-(5- dimethylaminonaphthalene-1-sulfonyl)dipalmitoylphosphatidylethanolamine in H2O and D2O buffer, assessing the degree of hydration in the head group region. The results revealed that incorporation of egg SM into triolein-egg phosphatidylcholine emulsions markedly increased acyl chain order and decreased head group hydration of the surface monolayers. In contrast, cholesterol was shown to increase head group hydration despite a strong increase in acyl chain order. The close correlation between the apparent K(m) values of LPL and the degree of head group hydration indicated that LPL interacts with the head group region rather than with the hydrophobic interior of the surface monolayers. However, apparent V(max) did not show a simple correlation with any surface structure, and the finding in which SM had no effect on apparent V(max) of medium-chain triglyceride emulsions suggested that the hydrophobic interaction between acyl chains of SM and triglyceride at the emulsion surface is important for determining the apparent V(max). These results showed conclusively that SM inhibits LPL activity mainly by changing the emulsion surface structure and not by a specific interaction between SM and LPL. (C) 2000 Elsevier Science B.V.

リンク情報
DOI
https://doi.org/10.1016/S1388-1981(00)00071-8
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/10903482
ID情報
  • DOI : 10.1016/S1388-1981(00)00071-8
  • ISSN : 1388-1981
  • PubMed ID : 10903482
  • SCOPUS ID : 0034686660

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