title: 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.
mesh_terms: D000818:Animals; D001665:Binding Sites; D002415:Cats; D055598:Chemical Phenomena; D002621:Chemistry; D003545:Cysteine / Q000378:metabolism; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology; D006454:Hemoglobins / Q000378:metabolism*; D006639:Histidine / Q000378:metabolism; D008956:Models, Chemical; D011485:Protein Binding / Q000187:drug effects; D011506:Proteins / Q000378:metabolism; D014220:Trialkyltin Compounds / Q000378:metabolism*; D014267:Triethyltin Compounds / Q000378:metabolism*
chemical_list: D006454:Hemoglobins; D011506:Proteins; D014220:Trialkyltin Compounds; D014267:Triethyltin Compounds; D006639:Histidine; D003545:Cysteine; D004047:Diethyl Pyrocarbonate