E. coli C-600의 $NADP^+$ 의존성 succinate semialdehyde dehydrogenase(SSALDH)를 ammonium sulfate 침전, DEAE-sephacel chromatography, hydroxylapatite chromatography 등의 방법으로 정제하였다. 분리정제한 succinate semialdehyde dehydrogenase의 분자량은 210,000 dalton이었으며, SDS-polyacrylamide 전기이동을 행한 결과 동일한 subunit로된 tetramer였고, subunit의 분자량은 50.100 dalton이었다. 이 효소의 succinate semialdehyde에 대한 $K_m$값은 $1.8{sim}10^{-5}M$인데 비해, indole-3-acetaldehyde semialdehyde나 glutaraldehyde에 대한 $K_m$값은 각각 2.7, 8mM로 높았으며 formaldehyde, acetaldehyde, propionaldehyde, glyceraldehyde, benzaldehyde에 대해서는 반응하지 않는 것으로 보아 이 효소는 주로 succinate semialdehyde에 대해 특이적으로 작용하고 E. coli의 에너지 이용이란 면에서 중요한 역할을 하는 것으로 생각된다. $NADP^+$에 대한 $K_m$은 $8.9{sim}10^{-5};M$, 최적 pH는 10.0, 최적온도는 $45^{circ}C$, pI값은 5.8이었다.
E. coli C-600 NADP-dependent succinate semialdehyde dehydrogenase was purified by successive ammonium sulfate precipitation, DEAE-sephacel chromatography and hydroxylapatite chromatography. The native molecular weight of purified succinate semialdehyde dehydrogenase was 210,000 dalton. This enzyme was identified to be tetramer of four identical 50,100 dalton subunits by SDS-polyacrylamide gel electrophoresis. The $K_m$ value of the enzyme for the indole-3-acetaldehyde and glutaraldehyde were 2.7 mM and 8 mM respectively while this enzyme showed no activity toward other aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, glyceraldehyde and benzaldehyde. This implies that the enzyme reacts specifically toward succinic semialdehyde and in this regard, this enzyme will have critical role in E. coli energy metabolism. The $K_m$ value toward $NADP^+$ was $8.9{sim}10^{-5};M$ and the pI value of this enzyme was 5.8. Maximal activity was seen at pH 10.0. Also the enzyme showed maximal activity at $45^{circ}C$.
