title: The reaction of trout hemoglobins with isocyanides.
abstract: Binding of alkylisocyanides of different bulkiness to the two major components of trout hemolysate is presented. In the case of trout hemoglobin I isocyanide binding is pH-independent, similar to O2 and CO, and the bulkiness of the ligand is related to the endothermicity of ligand binding to the T quaternary state. On the other hand, in trout hemoglobin IV the size of the ligand seems to affect the pH dependence of affinity and cooperativity. A comparison with other ligands, like O2, allows us to hint at possible stereochemical determinants of ligand binding in these two hemoglobins.
mesh_terms: D000818:Animals; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009570:Nitriles / Q000378:metabolism*; D012487:Salmonidae / Q000097:blood*; D013816:Thermodynamics; D014337:Trout / Q000097:blood*
chemical_list: D006454:Hemoglobins; D009570:Nitriles; C002990:butyl isocyanide; C039089:isopropyl isocyanide; C001187:ethyl isocyanide