Cytochrome oxidase from thermophilic bacterium PS3 contains a fourth protein subunit

Wen Zhi Gai, Shu Man Sun, Nobuhito Sone, Samuel H.P. Chan

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Monoclonal antibodies prepared against subunits II and IV of beef heart cytochrome oxidase were found to cross-react with thermophilic bacterial PS3 oxidase. Each individual antibody affects the enzymatic activity. "Western" blot analyses showed that subunit II antibodies of beef heart recognized subunit II of PS3 and subunit IV antibody likewise recognized a fourth protein subunit on slab gels. This fourth subunit previously thought to be a contaminant or a degradation product has a molecular weight of about 10,500 on SDS-gels, and appears to exist in stoichiometric amount. We have extracted this subunit from slab gels and compared its amino acid composition with that of subunit III.

Original languageEnglish (US)
Pages (from-to)414-421
Number of pages8
JournalBiochemical and Biophysical Research Communications
Issue number2
StatePublished - Jun 15 1990

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology


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