Identification of the two histidine residues responsible for the inhibition by malonyl-CoA in peroxisomal carnitine octanoyltransferase from rat liver

Montserrat Morillas, Josep Clotet, Blanca Rubí, Dolors Serra, Guillermina Asins, Joaquín Ariño, Fausto G. Hegardt

Research output: Contribution to journalArticleResearchpeer-review

19 Citations (Scopus)

Abstract

Carnitine octanoyltransferase (COT), an enzyme that facilitates the transport of medium chain fatty acids through peroxisomal membranes, is inhibited by malonyl-CoA. cDNAs encoding full-length wild-type COT and one double mutant variant from rat peroxisomal COT were expressed in Saccharomyces cerevisiae. Both expressed forms were expressed similarly in quantitative terms and exhibited full enzyme activity. The wild-type-expressed COT was inhibited by malonyl-CoA like the liver enzyme. The activity of the enzyme encoded by the double mutant H131A/H340A was completely insensitive to malonyl-CoA in the range assayed (2-200 μM). These results indicate that the two histidine residues, H131 and H340, are the sites responsible for inhibition by malonyl-CoA. Another mutant variant, H327A, abolishes the enzyme activity, from which it is concluded that it plays an important role in catalysis. Copyright (C) 2000 Federation of European Biochemical Societies.
Original languageEnglish
Pages (from-to)183-186
JournalFEBS Letters
Volume466
DOIs
Publication statusPublished - 21 Jan 2000

Keywords

  • Carnitine octanoyltransferase
  • Inhibitory kinetics
  • Malonyl-coenzyme A
  • Peroxisome
  • Rat liver
  • Site-directed mutagenesis

Fingerprint Dive into the research topics of 'Identification of the two histidine residues responsible for the inhibition by malonyl-CoA in peroxisomal carnitine octanoyltransferase from rat liver'. Together they form a unique fingerprint.

Cite this