Mass spectrometric identification of lysine residues of heme oxygenase-1 that are involved in its interaction with NADPH-cytochrome P450 reductase

Biochem Biophys Res Commun. 2008 Mar 21;367(4):852-8. doi: 10.1016/j.bbrc.2008.01.016. Epub 2008 Jan 14.

Abstract

The lysine residues of rat heme oxygenase-1 (HO-1) were acetylated by acetic anhydride in the absence and presence of NADPH-cytochrome P450 reductase (CPR) or biliverdin reductase (BVR). Nine acetylated peptides were identified by MALDI-TOF mass spectrometry in the tryptic fragments obtained from HO-1 acetylated without the reductases (referred to as the fully acetylated HO-1). The presence of CPR prevented HO-1 from acetylation of lysine residues, Lys-149 and Lys-153, located in the F-helix. The heme degradation activity of the fully acetylated HO-1 in the NADPH/CPR-supported system was significantly reduced, whereas almost no inactivation was detected in HO-1 in the presence of CPR, which prevented acetylation of Lys-149 and Lys-153. On the other hand, the presence of BVR showed no protective effect on the acetylation of HO-1. The interaction of HO-1 with CPR or BVR is discussed based on the acetylation pattern and on molecular modeling.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Computer Simulation
  • Enzyme Activation
  • Heme Oxygenase (Decyclizing) / chemistry*
  • Heme Oxygenase (Decyclizing) / ultrastructure*
  • Lysine / chemistry*
  • Mass Spectrometry
  • Models, Chemical*
  • Models, Molecular*
  • Molecular Sequence Data
  • NADPH-Ferrihemoprotein Reductase / chemistry*
  • NADPH-Ferrihemoprotein Reductase / ultrastructure*
  • Peptide Mapping
  • Protein Binding
  • Protein Interaction Mapping

Substances

  • Heme Oxygenase (Decyclizing)
  • Hmox1 protein, rat
  • NADPH-Ferrihemoprotein Reductase
  • Lysine