Detoxification of oxidized LDL by transferring its oxidation product(s) to lecithin:cholesterol acyltransferase

Zakir H. Howlader, Shin Kamiyama, Hitoshi Shirakawa, Yohei Murakami, Michiko Ito, Michio Komai, Koji Muramoto, Yuji Furukawa

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

In the present study, we isolated modified LCAT (m-LCAT) by hydroxyapatite column chromatography after incubation of crude LCAT (after DEAE SephadexA-50 column chromatography, penultimate step of LCAT purification) with oxidized LDL (oxLDL) at 37°C for 1 h. The activity was found to be about 30% lower than that of native LCAT (n-LCAT). When activity was determined in the presence of oxLDL, m-LCAT was less inhibited than n-LCAT by oxLDL. Treatments of purified LCAT either at 56°C for 30 min, at 100°C for 10 min, or with 6 mM 5-5′-dithiobis-2-nitrobenzoic acid or 9 mM diisopropyl fluorophosphates (each at 37°C for 30 min) resulted in the loss of its cholesterol-esterifying activity. When examined for their ability to detoxify oxLDL, native LCAT and LCAT treated at 56°C for 30 min were found to detoxify oxLDL. These results indicate that oxidation product(s) of LDL is transferred and bound to LCAT in a way that does not depend on its cholesterol-esterifying activity, but rather on the availability of the sulfhydryl group of cysteine residue and the hydroxyl group of serine residue.

Original languageEnglish
Pages (from-to)758-763
Number of pages6
JournalBiochemical and biophysical research communications
Volume291
Issue number4
DOIs
Publication statusPublished - 2002 Jan 1

Keywords

  • Detoxification
  • HDL
  • LCAT
  • Modified LCAT
  • Oxidized LDL
  • PL-OOH value TBARS value

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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