PHYLOGENY AND ONTOGENY OF THE PHOSPHOGLYCERATE MUTASES .2. CHARACTERIZATION OF PHOSPHOGLYCERATE MUTASE ISOZYMES FROM VERTEBRATES BY THEIR THERMAL LABILITY AND SENSITIVITY TO THE SULFHYDRYL-GROUP REAGENTS

To characterize the 3 phosphoglycerate mutase (PGM) isozymes present in vertebrates (types M, B and MB), their sensitivity to the reagents of the sulfhydryl groups and to heat treatment was studied. In mammals and reptiles type M PGM is not affected by the .sbd.SH group reagents, type MB PGM is inhibited about 50% and type B PGM is fully inhibited. Types B and MB PGM show greater heat lability than type M PGM. In amphibians and fishes PGM isozymes do not differ in their sensitivity to the .sbd.SH reagents. The results strongly support the homodimeric and heterodimeric structure suggested for PGM isozymes and favor their genetic origin. [The following species were used: man (Homo sapiens), Wistar rat (Rattus norvegicus), guinea pig (Cavia cobaya), rabbit (Oryctolagus cuniculus), cat (Felis domesticus), pig (Sus scrofa), calf (Bos taurus), chicken (Gallus domesticus), pigeon (Columba livia), turtle (Clemmys caspica), snake (Tropidonotus natrix), eft (Psammodromus algirus), gecko (Tarentola mauritanica), toad (Alytes obstetricans), frog (Rana ridibunda), dogfish (Scylliorhinus canicula), bogue (Boops boops) and pickerel (Esox lucius).].