Evidence for histidine in the triethyltin-binding site of rat haemoglobin.
One molecule of rat haemoglobin binds two molecules of triethyltin. The binding sites are located on the globin and there is co-operativity between the sites such that the intrinsic affinity constant at pH8.0 increases from 3.5x10(5)m(-1) for the binding of the first triethyltin molecule to 5.0x10(5)m(-1) for the binding of the second. Evidence is presented, from pH studies and the kinetics of inhibition due to photo-oxidation, that each binding site contains two histidine residues.
D000818:Animals; D001665:Binding Sites; D006454:Hemoglobins / Q000378:metabolism*; D006639:Histidine / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009942:Organometallic Compounds / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D051381:Rats; D014001:Tin / Q000378:metabolism*
D006454:Hemoglobins; D009942:Organometallic Compounds; D006639:Histidine; D014001:Tin