RESUMEN
Branched-chain alpha-ketoacid dehydrogenase complex (BCKDC) is a rate-limiting enzyme in the branched-chain amino acid catabolic pathway. We have developed a method of BCKDC purification from rat liver using hydrophobic interaction column chromatography (Shimomura et al., Arch. Biochem. Biophys., 283, 293-299 (1990)). Here we report a modification of the method designed to obtain the purified enzyme with high reproducibility.
Asunto(s)
3-Metil-2-Oxobutanoato Deshidrogenasa (Lipoamida)/aislamiento & purificación , Hígado/enzimología , Animales , Electroforesis en Gel de Poliacrilamida , RatasRESUMEN
Inhibition of branched-chain alpha-ketoacid dehydrogenase kinase (BDK) by thiamine pyrophosphate (TPP) was analyzed at two potassium ion (K(+)) concentrations. IC(50) values of 4.6 and 8.0 microM and inhibition constant values of 3.2 and 16.4 microM were obtained in the presence of 20 and 100 mM K(+), respectively. These results suggest that BDK is less sensitive to TPP inhibition under physiological TPP and K(+) concentrations.