title: Effect of substrate - binding on the immunologic reactivity of lobster - muscle arginine kinase : a comparison with rabbit - muscle creatine kinase.
abstract: The effects of substrate-binding upon the immunologic reactivity of rabbit creatine kinase and lobster arginine kinase have been investigated. The separate binding of the guanidine or the nucleotide substrate to creatine kinase yields no alteration of antigenicity and a substantial effect is only observed when all the loci at the active center of the enzyme, including that for the transferable phosphoryl group, are occupied. In contrast, the antigenic reactivity of arginine kinase is affected by the separate binding of either the guanidine or the nucleotide substrate, and the simultaneous binding of the two substrates results in a cumulative effect, which is irrespective of the phosphorylated or non-phosphorylated form of the complex. These results support the existence of substrate-induced conformational changes demonstrated by other methods, and they reveal appreciable differences in their effect on the antigenic reactivity of the two enzymes.
mesh_terms: D000818:Animals; D001120:Arginine / Q000378:metabolism*; D003402:Creatine Kinase / Q000378:metabolism; D009132:Muscles / Q000201:enzymology*; D008121:Nephropidae; D010770:Phosphotransferases / Q000276:immunology* / Q000378:metabolism; D011233:Precipitin Tests; D011487:Protein Conformation; D011817:Rabbits
chemical_list: D001120:Arginine; D010770:Phosphotransferases; D003402:Creatine Kinase