Identification, purification and separation of different isozymes of NADP-specific malic enzyme from Tritrichomonas foetus.

摘要: Tritrichomonas foetus was found to contain NADP-specific malic enzyme. The activity present in the cytosolic fraction and about 5-fold higher extracts of a metronidazole-resistant strain (KV1-1MR-100) than parent (KVc1). Electrophoresis under non-denaturing conditions staining indicated existence 3 isozymes termed I, II III order increasing electrophoretic mobility. Isozymes I were much less active isozyme strain, whereas all three had comparable activities resistant strain. NADP-malic enzymes purified from apparent homogeneity identified by SDS-PAGE as polypeptides 41.5 kDa (I), 40.5 (III) mixture both equal amounts (II). molecular mass holoenzymes 180 kDa, determined gel-filtration on Sephacryl S-300 HR, indicating tetrameric structure. Isozyme also shown consist 40.5-kDa polypeptide. Km values for malate 0.31, 0.65 1.35 mM III, respectively. From these results we conclude that T. foetus+, which is required formation ethanol alcohol dehydrogenase, an enzyme this species. This particularly important major end-product glucose metabolism.