Otro
Kinetic aspects of rat (Rattus-norvegicus albinus) submandibular glands lactic-dehydrogenase
Registro en:
Arquivos de Biologia E Tecnologia. Curitiba-Paraná: Inst Tecnologia Parana, v. 37, n. 2, p. 333-343, 1994.
0365-0979
WOS:A1994PL60300009
Autor
Sassaki, K. T.
Rosa, C. D.
Cesar, M. D.
Rosa, R.
Resumen
Submandibular glands of male rats were homogenized with 33 mM sodium potassium phosphate buffer, pH 6.5, containing 1 mM MgCl2 and 0.1 mM DTT and purified with ammonium sulphate, phosphocellulose chromatography, eluted with KC1 0.5 M, followed by Blue Sepharose CL-6B chromatography, eluted with NADH 0.5 mM. The enzyme kepts stable for 60 days when stored at -15-degrees-C in 33 mM phosphate buffer. In other experiment the enzyme was purified by oxamate-agarose chromatography from a crude extract of submandibular gland and the results obtained were better than by phosphocellulose and Sepharose CL-6B chromatography. The Km values for pyruvate. NADH, lactate and NAD+ were established. Sodium oxamate at 0.1 and 0.9 mM concentrations inhibited the LDH activity by 40 and 85%, respectively (competitive); with sodium oxalate the inhibition was of 30% (uncompetitive) and with 3-acetyl pyridine adenine dinucleotide was 80%.