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Triethyltin binding to cat haemoglobin. Evidence for two chemically distinct sites and a role for both histidine and cysteine residues.

ABSTRACT: Triethyltin binding to cat haemoglobin was measured after pretreatment of the protein with diethyl pyrocarbonate at pH 6.0,iodoacetamide or phenylmercuric acetate or by photo-oxidation in the presence of Methylene Blue. The pentaco-ordinate nature of the binding of triethyltin to cat haemoglobin is confirmed by the inability of intramolecularly pentaco-ordinate tin compounds to compete. Consideration of the symmetry of the haemoglobin molecule in the light of the above results suggests that a unique arrangement of histidine and cysteine residues is required for the binding of triethyltin. The effects of treatment with diethyl pyrocarbonate of other preparations which bind triethyltin (rat liver supernatant, a fraction from rat liver mitochondria and rat brain myelin) were determined and shown to be complex.

SUBMITTER: Elliott BM

PROVIDER: S-EPMC1186395 | biostudies-other | 1979 Feb

REPOSITORIES: biostudies-other

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Binding of triethyltin to cat haemoglobin and modification of the binding sites by diethyl pyrocarbonate.

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