Comparative characteristics of lactate dehydrogenase from the liver and white muscles of common carp (Cyprinus carpio)
Kubrak, O.I.; Lushchak, O.V.; Lushchak, V.I.
Ukrains'kyi Biokhimichnyi Zhurnal 80(4): 35-41
2008
ISSN/ISBN: 0372-3909 PMID: 19140448 Document Number: 627912
Lactate dehydrogenase from the liver and white muscles of common carp (Cyprinus carpio) was purified by the differential precipitation of supernatants with ammonium sulfate. The results of native electrophoresis of partially purified lactate degydrogenase (LDH) and LDH from some tissues exhibited the different isozyme composition there. However, the kinetic properties of these isozymes from two tissues were not different, except for the value of K(m) for pyruvate, which was 72.5 +/- 11 and 217 +/- 32 microM for the liver and muscle, respectively. LDH from the liver and white muscle had similar pH-dependences with pH-optima for the both LDH activities between 6.75 and 8.00. But studied isozymes demonstrated different thermostability. The partially purified LDH from the liver showed 450% activity after 2 h at 50 degrees C. In contrast, the partially purified LDH from the muscle exhibited about 300% activity after 3 h at 65 degrees C. The heating of partially purified LDH from the muscle caused complete purification of this isozyme.