Takada S, Tsuda M, Matsumoto M, Fujinami S, Yamamura M, Katsunuma T
Department of Biochemistry, School of Medicine, Tokai University, Isehara-shi, Japan.
Tokai J Exp Clin Med. 1988 Dec;13(6):321-7.
Incorporation of alpha-1-antichymotrypsin (ACT) into human stomach adenocarcinoma cell nuclei and the effect of ACT on DNA primase from the same carcinoma cells were studied. ACT or [125I]-ACT were observed in carcinoma cell nuclei and high specific radioactivity was detected in washed nuclear fraction when 0.4 mg of ACT or [125I] ACT (8 x 10(7) cpm) was intravenously injected into carcinoma bearing nude mice 2 h before killing. The molecular weight of radioactivity presented in cell nuclei was same as the intact ACT on SDS-polyacrylamide gel electrophoresis. ACT inhibited DNA primase activity and this inhibiting activity was stable than its chymotrypsin inhibiting activity. The results presented here show ACT is incorporated into carcinoma cell nuclei without modification of its molecular weight and may inhibit DNA primase activity.
研究了α-1-抗糜蛋白酶（ACT）进入人胃腺癌细胞核的情况以及ACT对同一癌细胞中DNA引发酶的影响。当在处死前2小时向荷瘤裸鼠静脉注射0.4mg ACT或[125I]-ACT（8×10⁷cpm）时，在癌细胞核中观察到了ACT或[125I]-ACT，并且在洗涤后的核组分中检测到了高比放射性。在SDS-聚丙烯酰胺凝胶电泳上，细胞核中呈现的放射性的分子量与完整的ACT相同。ACT抑制DNA引发酶活性，并且这种抑制活性比其抑制糜蛋白酶的活性更稳定。此处给出的结果表明ACT未经分子量改变就进入了癌细胞核，并且可能抑制DNA引发酶活性。
