대두 축 추출물에서$gamma$-aminobutyraldehyde 탈수소효소(EC 1.2.1.19; 4-aminobutyraldehyde: NAD oxidoreductase)를 순수 정제 하였다. 정제된 효소는 Sephacryl S-300 gel filtration과 SDS polyacrylamide gel electrophoresis를 시 행하여 분자량이 같은 64,000 da1tons의 subunit 2개로 구성된 dimer임을 알 수 있었다. 이 효소는 $gamma$-aminobutyraldehyde와 $NAD^+$에 대하여 선택적으로 높은 기질 특이성을 보였고 $gamma$-aminobutyraldehyde와 $NAD^+$ 그리고 $NADP^+$에 대한 $K_m$값은 각각 $15;{mu}M$, $60;{mu}M$, 3 mM이었다. 이 효소의 최적 pH는 8.5였으며, 정제된 효소의 활성은 $Zn^{2+}$에 의하여 억제되였다. 또한 이 효소는 iodoacetamide, p-chloromercuribenzonate, N-ethylmaleimide에 의하여 활성이 크게 억제되었다. 이는 효소 활성에 cysteine residue가 관여하는 것으로 추측된다.
$gamma$-aminobutyraldehyde dehydrogenase(EC 1.2.1.19; 4-aminobutyraldehyde:NAD oxidoreductase) was purified to homogeneity from extracts of soybean (Glycine max) axes. The purified enzyme has been shown to consist of two apparently identical subunits of 64,000 daltons as determined by gel filtration and SDS polyacrylamide gel electrophoresis. High specificity exists only for $gamma$-aminobutyraldehyde and $NAD^+$; the $K_m$ value was $15;{mu}M$ for $gamma$-aminobutyraldehyde, $60;{mu}M$ for $NAD^+$, and 3 mM for $NADP^+$, respectively. Optimal pH for the activity was 8.5. $Zn^{2+}$ was observed to inhibit the purified enzyme. And iodoacetamide, p-chloromercuribenzoate and N-ethylmaleimide were turned out to inhibit the enzyme, suggesting that the cysteine residue got involved in the enzyme activity.
