Localization of apolipoprotein A-I epitopes involved in the activation of lecithin: Cholesterol acyltransferase

Patrizia Uboldi, Monica Spoladore, Simona Fantappiè, Santica Marcovina, Alberico L. Catapano

Research output: Contribution to journalArticle

Abstract

Eight murine monoclonal antibodies (Mab) to apolipoprotein A-I were characterized for their epitopes and for their ability to interfere with lecithin: cholesterol acyltransferase (LCAT) activation mediated by apo apoA- I using a synthetic substrate. Using overlapping synthetic peptides we have identified six continuous epitopes that span amino acids 1-10 (Mab A-I-19), 96-101 (Mab A-I-15), 133-141 (Mab A-I-5), 140-145 (Mab A-I-9), 144-148 (Mab A-I-8), and 167-174 (Mab A-I-57). Furthermore, antibodies A-I-11 and A-I-16 recognized discontinuous epitopes, namely amino acids 124-128 and 144-148, when antibodies were tested for their ability to inhibit LCAT activation, an inhibitory effect was observed with those whose epitopes covered the area of apoA-I encompassing amino acids 96-174. From these data we conclude that several areas of apoA-I spanning the middle region of the apolipoprotein act in concert to stimulate LCAT activity, possibly by cooperative interaction with the enzyme.

Original languageEnglish
Pages (from-to)2557-2568
Number of pages12
JournalJournal of Lipid Research
Volume37
Issue number12
Publication statusPublished - Dec 1996

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Keywords

  • epitopes
  • Fab fragments
  • HDL
  • monoclonal antibodies

ASJC Scopus subject areas

  • Endocrinology

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