쥐의 뇌 시토졸 Aldehyde Dehydrogenase 의 정제 및 특성에 관한 연구 = Purification and Characterization of Rat Brain cytosolic Aldehyde Dehydrogenase

다국어 초록 (Multilingual Abstract)

Rat brain cytosolic aldehyde dehydrogenase (ALDH, EC 1.2.1.3) was purified by ammonium sulfate precipitation, DEAF-Sephacel, Blue Sepharose CL-6B and 5`-AMP Sepharose 4B affinity chromatography. K_m values of the cytosolic ALDH for short chain aliphatic aldehyde and aromatic aldehyde were 10^(-3)M level and that for indole-3-acetaldehyde was 10^(-4)M level. However, this enzyme had a very low Km value (10^(-6) level) and the greatest affinity for succinic semialdehyde suggesting that the cytosolic ALDH seemed to be closely related to the metabolism of γ-aminobutyrate. K_m of this enzyme for NAD was 10^(-5)M level while that for NADP+ was 10^(-4) M level. It seemed that NAD+ might be mainly used as a cofactor of this enzyme. Rat brain cytosolic ALDH was sensitive to disulfiram and the enzyme activity decreased to about 50% in the presence of 10 μM disulfiram but 30% of the total activity of this enzyme remained even in the presence of 25 μM disulfiram. This enzyme had esterase activity as well. It was realized that iodoacetamide, phenylmethylsulfonylfluoride, pyridoxal-5`-phosphate inhibited the enzyme activity suggesting that amino acid residues such as cys-teine, serine, lysine might participate at the active site of this enzyme.