The Preparation and Properties of Triosephosphate Isomerase from Chicken Muscle and a Comparison with that from Rabbit Muscle

A method is described for the purification of the enzyme triosephosphate isomerase from chicken breast muscle. The physical properties are compared with those of triosephosphate isomerase from rabbit muscle. The enzyme prepared from chicken muscle was homogeneous as judged by electrophoresis in polyacrylamide gels and equilibrium sedimentation studies. The molecular weight of the native chicken muscle enzyme was 48400 ± 700 (S.D.) and the subunits had a molecular weight of 25000 ± 1000 (S.D.). The values obtained for the rabbit muscle enzyme were 50500 ± 1500 (S.D.) and 26000 ± 1000 (S.D.), respectively. On the basis of sedimentation velocity runs with various molarities of guanidinium chloride as solvent, the separation of subunits and the unfolding of these subunits was shown to occur simultaneously upon denaturation of the chicken muscle enzyme. Some preparations of guanidinium chloride, which was used as a denaturant, were shown to possess lytic activity.