Cardiolipin modulates allosterically peroxynitrite detoxification by horse heart cytochrome c

Paolo Ascenzi, Chiara Ciaccio, Federica Sinibaldi, Roberto Santucci, Massimo Coletta

Research output: Contribution to journalArticlepeer-review


Upon interaction with bovine heart cardiolipin (CL), horse heart cytochrome c (cytc) changes its tertiary structure disrupting the heme-Fe-Met80 distal bond, reduces drastically the midpoint potential out of the range required for its physiological role, binds CO and NO with high affinity, and displays peroxidase activity. Here, the effect of CL on peroxynitrite isomerization by ferric cytc (cytc-Fe(III)) is reported. In the absence of CL, hexa-coordinated cytc does not catalyze peroxynitrite isomerization. In contrast, CL facilitates cytc-Fe(III)-mediated isomerization of peroxynitrite in a dose-dependent fashion inducing the penta-coordination of the heme-Fe(III)-atom. The value of the second order rate constant for CL-cytc-Fe(III)-mediated isomerization of peroxynitrite (kon) is (3.2±0.4)×105M-1s-1. The apparent dissociation equilibrium constant for CL binding to cytc-Fe(III) is (5.1±0.8)×10-5M. These results suggest that CL-cytc could play either pro-apoptotic or anti-apoptotic effects facilitating lipid peroxidation and scavenging of reactive nitrogen species, such as peroxynitrite, respectively.

Original languageEnglish
Pages (from-to)190-194
Number of pages5
JournalBiochemical and Biophysical Research Communications
Issue number1
Publication statusPublished - Jan 7 2011


  • Allostery
  • Cardiolipin
  • Horse heart cytochrome c
  • Peroxynitrite isomerization

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Cell Biology
  • Molecular Biology


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