Incorporation of alpha-1-antichymotrypsin into human stomach adenocarcinoma cell nuclei and inhibition of DNA primase activity.
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.
Takada
S
S
Department of Biochemistry, School of Medicine, Tokai University, Isehara-shi, Japan.
Tsuda
M
M
Matsumoto
M
M
Fujinami
S
S
Yamamura
M
M
Katsunuma
T
T
D000230:Adenocarcinoma / Q000378:metabolism*; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D019915:DNA Primase; D004261:DNA Replication; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D012316:RNA Nucleotidyltransferases / Q000037:antagonists & inhibitors*; D013274:Stomach Neoplasms / Q000378:metabolism*; D000514:alpha 1-Antichymotrypsin / Q000378:metabolism*
D000514:alpha 1-Antichymotrypsin; D019915:DNA Primase; D012316:RNA Nucleotidyltransferases