돼지회충 근육조직의 FAD의존성 α-Glycerophosphate 탈수소 효소의 정제 및 성상 = Purification and Characterization of FAD-linked α-Glycerophosphate Dehydrogenase from Ascaris suum Muscle

다국어 초록 (Multilingual Abstract)

Ascaris suum muscle was fractionated by differential centrifugation into nuclear, mitochondrial and cytoplasmic fractions. The activity of mitochondrial FAD-linked α-glycerophosphate dehydrogenase(cytochrome oxidoreductase, EC 1.1.99.5) was determined by the procedure of Dowson and Thorne, and the activity of cytoplasmic NAD-linked α-glycerophosphate dehydrogenase(NAD 2-oxidoreductase, EC 1.1.1.8) was assayed according to the method of Gonzalez-Cerozo and Dalziel. Mitochondrial FAD-linked α-glycerophosphate dehydrogenase was purified by sodium deoxycholate solubilization and DEAE-cellulose column chromatography.
The results obtained were as follows;
1. The distribution of FAD-linked α-glycerophospliate dehydrogenase in the subcellular organells showed that 62% of the activity was in mitochondrial, 29% in cytoplasmic and about 9% was in nuclear fraction.
The specific activities were 1.26, 0.30, and 0.05, respectively.
2. The activity of FAD-linked α-glycerophosphate dehydrogenase in Ascaris suum muscle was 153.25 units/g. The specific activity of NAD-linked α-glycerophosphate dehydrogenase in cytosol was found to be about 2 fold greater than that of FAD-linked dehydrogenase in mitochondria.
3. It was demonstrated that there were two types of isozyme in the mitochondrial FAD-linked dehydrogenase, Enzyme Ⅰ and Enzyme Ⅱ. Enzyme Ⅰ and Ⅱ were purified about 87 and 854-fold increase in specific activities after chromatography on DEAE-cellulose.
4. The specific activity of Enzyme Ⅱ was found 9.8 times as high as Enzyme Ⅰ, and Enzyme Ⅰ and Ⅱ were contained 87.7% and 12.3% respectively.
5. The optimal temperature of Enzyme Ⅰ and Ⅱ were 35℃ and the optimal pH of Enzyme Ⅰ and Ⅱ were 7.6.
6. The Km values for α-glycerophosphate of Enzyme Ⅰ and Ⅱ were 2.33 mM and 0.82 mM, respectively.