토끼의 골수에서 세포질과 mitochondria 분획을 분리하고 세포질에 있는 $alpha$-glycerophosphate 탈수소 효소($NAD^+$ 2-oxidoreductase, EC 1.1.1.8) 및mitochondria에 있는 FAD 의 혼성 $alpha$-glycerophosphate 탈수소 효소(cytochrome oxidoreductase, EC 1.1.99.5)의 분포를 관찰하였다. NAD 의존성 효소의 활성도는 Gonzalez-Cerozo and Dalziel 법으로, 그리고 FAD 의존성 효소의 활성도는 Swierczynski 등의 방법으로 각각 측정 하였다. 골수 1 g당 세포질에 있는 NAD 의존성 효소의 활성도는 약 3112 unit로 총 활성도에 대하여 약 97%가 세포질에 함유되어 있었다. Mitochondria 에 있는 FAD 의존성 효소의 활성도는 약 61 unit 로 총 활성도에 대하여 약 50~60%가 mitochondria 에 함유되어 있다. NAD 의존성 효소의 비활성도는 신선한 골수 1 g 당 17.1이며 mitochondria에 있는 FAD 의존성 효소의 비활성도는 1.4로 NAD 의존성 효소와 약 12배의 차이가 있으나 다른 조직의 그것 보다는 모두 상당히 높았다. 세포질에 있는 NAD 의존성 효소를 ammonium sulfate 에 의한 침전 및 DEAE-cellulose column chromatography 등으로 정제하여 326배 정제하였다. 정제된 이 효소의 반응최적 pH 는 9.5이며 최적온도는 $45^{circ}$였다. 이 효소의 $alpha$-glycerophosphate 및 $NAD^+$에 대한 Km 값은 각각 3.1mM 및 0.54mM였다. $K^+$ 및 $Na^+$은 낮은 농도($1{ imes}10^{-6}M$)에서도 NAD 의존성 효소의 활성 억제하나 $Ca^{+2}$와 $Mg^{+2}$는 $1{ imes}10^{-6}M$ 농도에서 각각 효소의 활성을 촉진하였으며 농도의 증가에 따라 활성이 더욱 증가되었다. pCMB는 $1{ imes}10^{-6}M$농도에서 NAD 의존성 효소의 활성이 15% 억제되었으며 $1{ imes}10^{-3}M$에서는 88.5% 억제되었다. 정제된 NAD 의존성 효소를 $50^{circ}C$로 처리하였을 때 태반조직의 이 효소보다 더 열에 대하여 안정하였다.
The distribution and some properties of $alpha$-glycerophosphate dehydrogenase of rabbit bone marrow have been studied. The activity of cytosolic NAD-linked $alpha$-glycerophosphate dehydrogenase (sn-glycerol-3-phosphate: NAD 2-oxidoreductase, EC 1.1.1.8) was measured by the method of Gonzalez-Cerozo and Dalziel and the activity of FAD-linked $alpha$-glycerophosphate dehydrogenase (sn-glycerol-3-phosphate: cytochrome oxidoreductase, EC 1.1.99.5) was estimated according to the method of Swierczynski. The activity of NAD-linked dehydrogenase was present to localize about 97% in cytosolic fraction. This fraction possess a markedly high level of the enzyme, and the activity was about 3,200 units per g wet tissue. The specific activity was 17.1. The distribution of FAD-linked dehydrogenase in the subcell organells showed that 50-60% of the activity was in mitochondrial, 20-30% in cytosolic and about 10% was in nuclear fraction. The specific activities were 0.2, 1.4. an 0.26, respectively. Cytosolic NAD-linked $alpha$-glycerophosphate dehydrogenase has been partially purified about 320-fold by ammonium sulfate precipitation and DEAE-cellulose column chromatography. The optimal pH was 9.5 and the optimal temperature was $45^{circ}$. The Km values for $alpha$-glycerophosphate and $NAD^+$ were 3. 1 mM and 0. 54 mM, respectively. The enzyme was inhibited by $Ca^{2+}$ and $Na^+$ at the concentration of $1.0;{mu}M$ or greater, and stimulated by $Ca^{2+}$ and $Mg^{2+}$ at the concentration of $1.0;{mu}M$. The enzyme was also inhibited by low concentration of $1.0;{mu}M$ of p-chloromercuribenzoate, and at 1.0 mM the enzyme activity showed only 10% of the original activity. The purified cytosolic NAD-linked $alpha$-glycerophosphate dehydrogenase from rabbit bone marrow was found to be more stable than those of placenta on heat treatment.
