Papas T S, Pry T W, Chirigos M A
Proc Natl Acad Sci U S A. 1974 Feb;71(2):367-70. doi: 10.1073/pnas.71.2.367.
PYRAN COPOLYMER, A KNOWN IMMUNOSTIMULATOR, WAS FOUND TO BE A POTENT INHIBITOR OF PURIFIED DNA POLYMERASE (DEOXYNUCLEOSIDETRIPHOSPHATE: DNA deoxynucleotidyltransferase; EC 2.7.7.7) isolated from avian myeloblastosis virus. Unlike other inhibitors, pyran showed unique features of inhibition. It interacts with the polymerase at a region other than the template site. The inhibitory effect was overcome only by excess enzyme and not affected by excess template. The degree of inhibition was not template specific for the templates tested: 70S RNA from avian myeloblastosis virus, synthetic hybrid poly(rA).oligo(dT)(10), synthetic copolymer poly(dA-dT), and activated calf-thymus DNA. The observed rate of inhibition by pyran was shown to vary with the different polymerases tested. Inhibition was shown with all oncornaviral polymerases and, to a lesser extent, with mammalian polymerases. However, two of the three bacterial polymerases, by contrast, showed a marked activation.
已知的免疫刺激剂吡喃共聚物被发现是从禽成髓细胞瘤病毒中分离出的纯化DNA聚合酶(脱氧核苷三磷酸:DNA脱氧核苷酸转移酶;EC 2.7.7.7)的强效抑制剂。与其他抑制剂不同,吡喃显示出独特的抑制特性。它在模板位点以外的区域与聚合酶相互作用。只有通过过量的酶才能克服这种抑制作用,而过量的模板不会对其产生影响。对于所测试的模板,抑制程度并非模板特异性的,这些模板包括:禽成髓细胞瘤病毒的70S RNA、合成杂交聚(rA)·寡聚(dT)(10)、合成共聚物聚(dA-dT)以及活化的小牛胸腺DNA。已表明,吡喃的观察到的抑制速率随所测试的不同聚合酶而变化。所有的肿瘤病毒聚合酶都显示出抑制作用,而哺乳动物聚合酶的抑制作用较小。然而,相比之下,三种细菌聚合酶中的两种显示出明显的激活作用。