Turpin J A, Terpening S J, Schaeffer C A, Yu G, Glover C J, Felsted R L, Sausville E A, Rice W G
Laboratory of Antiviral Drug Mechanisms, National Cancer Institute-Frederick Cancer Research and Development Center, SAIC Frederick, Maryland 21702, USA.
J Virol. 1996 Sep;70(9):6180-9. doi: 10.1128/JVI.70.9.6180-6189.1996.
The Cys-Xaa2-Cys-Xaa4-His-Xaa4-Cys zinc fingers of retroviral nucleocapsid proteins are prime antiviral targets because of conservation of the Cys and His chelating residues and the absolute requirement of these fingers in both early and late phases of retroviral replication. We previously reported that certain disulfide-substituted benzamides (DIBAs) chemically modify the Cys residues of the fingers, resulting in inhibition of human immunodeficiency virus type 1 (HIV-1) replication (W. G. Rice, J. G. Supko, L. Malspeis, R. W. Buckheit, Jr., D. Clanton, M. Bu, L. Graham, C. A. Schaeffer, J. A. Turpin, J. Domagala, R. Gogliotti, J. P. Bader, S. M. Halliday, L. Coren, R. C. Sowder II, L. O. Arthur, and L. E. Henderson, Science 270:1194-1197, 1995). We now examine the consequences of the interaction of DIBAs with the zinc fingers of the HIV-1 p7 nucleocapsid protein and its Pr55gag precursor. In HIV-1-infected U1 cells, DIBAs inhibited the release of infectious virions, and even under conditions in which virion particles were produced, the particles were noninfectious. DIBAs caused abnormal processing of Gag precursors, and the inhibitory effect on processing was not due to inhibition of the HIV-1 protease enzyme or Pr55gag myristoylation. Rather, the defect in processing was due to the formation of intermolecular cross-linkages among the zinc fingers of adjacent Gag molecules, rendering the precursors no longer recognizable by HIV-1 protease. Likewise, DIBAs caused intermolecular cross-linkage among recombinant Pr55gag packaged into pseudovirions, thereby generating modified precursors that were resistant to the action of protease. Thus, DIBAs chemically modified the mutationally intolerant retroviral zinc fingers in infected cells, interrupting protease-mediated maturation of virions and leading ultimately to the production of compromised virions.
逆转录病毒核衣壳蛋白的Cys-Xaa2-Cys-Xaa4-His-Xaa4-Cys锌指是主要的抗病毒靶点，因为半胱氨酸（Cys）和组氨酸（His）螯合残基具有保守性，且这些锌指在逆转录病毒复制的早期和晚期阶段都是绝对必需的。我们之前报道过，某些二硫键取代的苯甲酰胺（DIBAs）能化学修饰锌指的半胱氨酸残基，从而抑制1型人类免疫缺陷病毒（HIV-1）的复制（W.G.赖斯、J.G.苏普科、L.马尔佩斯、R.W.巴克海特、D.克兰顿、M.布、L.格雷厄姆、C.A.谢弗、J.A.特平、J.多马加拉、R.戈廖蒂、J.P.巴德、S.M.哈利迪、L.科伦、R.C.索德二世、L.O.亚瑟和L.E.亨德森，《科学》270:1194 - 1197, 1995）。我们现在研究DIBAs与HIV-1 p7核衣壳蛋白及其Pr55gag前体的锌指相互作用的后果。在HIV-1感染的U1细胞中，DIBAs抑制了感染性病毒粒子的释放，而且即使在产生病毒粒子的条件下，这些粒子也没有感染性。DIBAs导致Gag前体的加工异常，并且对加工的抑制作用并非由于抑制HIV-1蛋白酶或Pr55gag的肉豆蔻酰化。相反，加工缺陷是由于相邻Gag分子的锌指之间形成了分子间交联，使得前体不再能被HIV-1蛋白酶识别。同样，DIBAs在包装入假病毒颗粒的重组Pr55gag之间引起分子间交联，从而产生对蛋白酶作用具有抗性的修饰前体。因此，DIBAs在感染细胞中化学修饰了对突变不耐受的逆转录病毒锌指，中断了蛋白酶介导的病毒粒子成熟，最终导致产生有缺陷的病毒粒子。
