Observation of the FeIVO stretching Raman band for a thiolate-ligated heme protein Compound I of chloroperoxidase

Tsuyoshi Egawa, Hideho Miki, Takashi Ogura, Ryu Makino, Yuzuru Ishimura, Teizo Kitagawa

Research output: Contribution to journalArticlepeer-review

31 Scopus citations


The FeIVO stretching vibration has never been identified for a cysteine-coordinated heme enzyme. In this study, resonance Raman and visible absorption spectra were observed simultaneously for transient species in the catalytic reaction of chloroperoxidase with hydrogen peroxide by using our original apparatus for mixed-flow and Raman/absorption simultaneous measurements. For the first intermediate, the FeIVO stretching Raman band was observed at 790 cm-1, which shifted to 756 cm-1 with the 18O derivative, but the ν4 band was too weak to be identified. This suggested the formation of an oxoferryl porphyrin π cation radical. The second intermediate gave an intense ν4 band at 1,372 cm-1 but no oxygen isotope-sensitive Raman band, suggesting oxygen exchange with bulk water.

Original languageEnglish (US)
Pages (from-to)206-208
Number of pages3
JournalFEBS Letters
Issue number3
StatePublished - Jul 6 1992


  • Chloroperoxidase
  • Compound I
  • Compound II
  • Ferryl-oxo stretching mode
  • Resonance Raman
  • Thiolate-ligated heme

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology


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