The interaction of short chain coenzyme Q analogs with different redox states of myoglobin

Alvaro Mordente, Stefano Angelo Santini, Giacinto Abele Donato Miggiano, Giuseppe Ettore Martorana, Bruno Giardina, T Petitti, G Minotti

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Two-equivalent oxidation of metmyoglobin (MbIII) by hydrogen peroxide (H2O2) yields an oxoferryl moiety (MbIV) plus a protein radical which presumably originates from the conversion of tyrosines to tyrosyl radicals (-MbIV). In the absence of electron donors, MbIII oxidation is followed by (i) heme degradation or (ii) tyrosyl radical-dependent reactions, such as irreversible dimerization or covalent binding of the heme group to the apoprotein. Moreover, the oxidizing equivalents of H2O2-activated MbIII promote the peroxidative decomposition of polyunsaturated fatty acids. In this study, water-soluble short chain coenzyme Q analogs (CoQ1H2 and CoQ2H2) were found to reduce the oxoferryl moiety, preventing heme degradation and regenerating MbIII and, more slowly, MbIIO2. CoQ1H2 and CoQ2H2 were also found to reduce tyrosyl radicals generated by UV irradiation of tyrosine solutions. Accordingly, CoQ1H2 and CoQ2H2 effectively prevented tyrosyl radical-dependent reactions such as the dimerization of sperm whale myoglobin and heme-apoprotein covalent binding in horse heart myoglobin. By competing for the oxidizing equivalents of hypervalent myoglobin, CoQ1H2 and CoQ2H2 also prevented the peroxidation of arachidonic acid. Collectively, these studies suggest that the proposed function of coenzyme Q as a naturally occurring antioxidant might well relate to its ability of reducing H2O2-activated myoglobin. Coenzyme Q should therefore mitigate cardiac or muscular dysfunctions that are caused by an abnormal generation of H2O2.
Original languageEnglish
Pages (from-to)27394-27400
Number of pages7
JournalTHE JOURNAL OF BIOLOGICAL CHEMISTRY
Volume269
Publication statusPublished - 1994

Keywords

  • Acetylation
  • Aerobiosis
  • Animals
  • Heme
  • Horses
  • Myoglobin
  • Oxidation-Reduction
  • Oxygen Consumption
  • Spectrometry, Fluorescence
  • Tyrosine
  • Ubiquinone

Fingerprint

Dive into the research topics of 'The interaction of short chain coenzyme Q analogs with different redox states of myoglobin'. Together they form a unique fingerprint.

Cite this