Redox equilibria of liganded forms of methemoglobin

C. Bull, B. M. Hoffman

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


The authors examined the redox equilibria of azidomethemoglobin (low spin) and fluoromethemoglobin (high spin). A modified Hill equation was derived which includes the tetramer dimer equilibrium of the oxidized form, and also generalized the 2 state model to incorporate ligand binding to the ferriheme. The pH dependence of the redox Hill's constant for fluoromethemoglobin is the same as that for methemoglobin, demonstrating that this dependence and the marked cooperativity achieved (n =2.2) are not coupled to changes of the ferriheme spin state. The redox Hill's constant for azidomethemoglobin, however, is as large as the oxygenation Hill's constant (n 2.7) and is also roughly pH independent.

Original languageEnglish (US)
Pages (from-to)3382-3386
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number9
StatePublished - 1975

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Redox equilibria of liganded forms of methemoglobin'. Together they form a unique fingerprint.

Cite this