Structural model for the trialkyltin binding site on cat hemoglobin.
The binding site for trialkyltin complexes on the alpha- chain of cat oxyhemoglobins is proposed to involve the SG and NE2 atoms of Cys-13 and His-113 respectively. On deoxygenation, the conformation of this region changes substantially, allowing complexation only through the ND1 nitrogen atom of His-113, a much less favorable interaction. Thus the model presented explains the preferential binding of trialkyltin complexes to R-state cat hemoglobin and suggests the type of interaction that is likely to occur between these compounds and a variety of less well-characterized enzymes to produce the metabolic effects that trialkyltin complexes are known to produce in vivo.
D000818:Animals; D001665:Binding Sites; D002415:Cats; D006454:Hemoglobins; D008956:Models, Chemical; D015394:Molecular Structure; D011487:Protein Conformation; D014220:Trialkyltin Compounds
D006454:Hemoglobins; D014220:Trialkyltin Compounds