KINETIC AND IMMUNOLOGICAL DIFFERENCES BETWEEN THE RETINAL SPECIFIC C-4-LACTATE AND B-4-LACTATE DEHYDROGENASE OF THE CICHLID FISH OREOCHROMIS-MOSSAMBICUS

The eye-specific C-4- lactate dehydrogenase (LDH) and the widely distr ibuted B-4-LDH isozymes from the fish Oreochromis mossambicus were pur ified to homogeneity using DEAE Sepharose ion-exchange chromatography and oxamate-linked sepharose affinity-chromatography. Kinetic analysis was performed on pure B-4- and C(4)LDH. The Michaelis-Menten constant (K-m) for B-4-LDH and pyruvate was 32.3 mu M, for B-4-LDH and lactate 717 mu M for C-4-LDH and pyruvate 14.1 mu M and for C-4-LDH and lacta te 1898 mu M. The pure C-4-isozyme was subjected to SDS-polyacrylamide gel electrophoresis and the Coomassie Brilliant Blue-stained band inj ected into a rat to produce antiserum. The antiserum proved to be C-4- LDH monospecific, which will allow using it to localize the isozyme in the retina at a light and electron microscopical level.