Isolation of a myoglobin molten globule by selective cobalt(III)-induced unfolding

O. Blum, A. Haiek, D. Cwikel, Z. Dori, T. J. Meade, H. B. Gray

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


Reaction of the Schiff-base complex [Co(acetylacetonate-ethylenediimine)(NH3)2]+ with metmyoglobin at pH 6.5 yields a partially folded protein containing six Co(III) complexes. Although half of its α-helical secondary structure is retained, absorption and CD spectra indicate that the tertiary structure in both B-F and AGH domains is disrupted in the partially folded protein. In analogy to proton-induced unfolding, it is likely that the loss of tertiary structure is triggered by metal-ion binding to histidines. Cobalt(III)-induced unfolding of myoglobin is unique in its selectivity (other proteins are unaffected) and in allowing the isolation of the partially folded macromolecule (the protein does not refold or aggregate upon removal of free denaturant).

Original languageEnglish (US)
Pages (from-to)6659-6662
Number of pages4
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number12
StatePublished - Jun 9 1998


  • Cobalt complexes
  • Protein unfolding

ASJC Scopus subject areas

  • General


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