1. Reactivity of ferrous myoglobin at low pH
- Author
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Gm Giacometti, Eraldo Antonini, Paolo Ascenzi, Maurizio Brunori, Tg Traylor, Giacometti, Gm, Traylor, Tg, Ascenzi, Paolo, Brunori, M, and Antonini, E.
- Subjects
Carbon Monoxide ,Myoglobin ,Iron ,Kinetics ,Inorganic chemistry ,Whales ,Protonation ,Cell Biology ,Hydrogen-Ion Concentration ,Biochemistry ,Ferrous ,Reaction rate ,chemistry.chemical_compound ,chemistry ,Animals ,Reactivity (chemistry) ,Molecular Biology ,Heme ,Carbon monoxide - Abstract
The rates of reaction of myoglobin with carbon monoxide at low pH are reported. The pH versus rate profile of these kinetics resembles that found for heme model compounds, revealing an increase in combination rate at low pH. These facts suggest that CO binding by myoglobin changes from a mechanism of "direct ligant association" at pH 5 to a mechanism, similar to that proposed for heme model compounds, which assumes a tetracoordinated intermediate as a result of the protonation of the proximal imidazole.
- Published
- 1977