Lee-Huang S, Huang P L, Huang P L, Bourinbaiar A S, Chen H C, Kung H F
Department of Biochemistry, New York University School of Medicine, NY 10016, USA.
Proc Natl Acad Sci U S A. 1995 Sep 12;92(19):8818-22. doi: 10.1073/pnas.92.19.8818.
MAP30 (Momordica anti-HIV protein of 30 kDa) and GAP31 (Gelonium anti-HIV protein of 31 kDa) are anti-HIV plant proteins that we have identified, purified, and cloned from the medicinal plants Momordica charantia and Gelonium multiflorum. These antiviral agents are capable of inhibiting infection of HIV type 1 (HIV-1) in T lymphocytes and monocytes as well as replication of the virus in already-infected cells. They are not toxic to normal uninfected cells because they are unable to enter healthy cells. MAP30 and GAP31 also possess an N-glycosidase activity on 28S ribosomal RNA and a topological activity on plasmid and viral DNAs including HIV-1 long terminal repeats (LTRs). LTRs are essential sites for integration of viral DNA into the host genome by viral integrase. We therefore investigated the effect of MAP30 and GAP31 on HIV-1 integrase. We report that both of these antiviral agents exhibit dose-dependent inhibition of HIV-1 integrase. Inhibition was observed in all of the three specific reactions catalyzed by the integrase, namely, 3' processing (specific cleavage of the dinucleotide GT from the viral substrate), strand transfer (integration), and "disintegration" (the reversal of strand transfer). Inhibition was studied by using oligonucleotide substrates with sequences corresponding to the U3 and U5 regions of HIV LTR. In the presence of 20 ng of viral substrate, 50 ng of target substrate, and 4 microM integrase, total inhibition was achieved at equimolar concentrations of the integrase and the antiviral proteins, with EC50 values of about 1 microM. Integration of viral DNA into the host chromosome is a vital step in the replicative cycle of retroviruses, including the AIDS virus. The inhibition of HIV-1 integrase by MAP30 and GAP31 suggests that impediment of viral DNA integration may play a key role in the anti-HIV activity of these plant proteins.
MAP30（30千道尔顿的苦瓜抗HIV蛋白）和GAP31（31千道尔顿的红雀珊瑚抗HIV蛋白）是我们从药用植物苦瓜和红雀珊瑚中鉴定、纯化并克隆出来的抗HIV植物蛋白。这些抗病毒剂能够抑制1型HIV（HIV-1）在T淋巴细胞和单核细胞中的感染，以及该病毒在已感染细胞中的复制。它们对正常未感染细胞无毒，因为它们无法进入健康细胞。MAP30和GAP31还对28S核糖体RNA具有N-糖苷酶活性，对包括HIV-1长末端重复序列（LTRs）在内的质粒和病毒DNA具有拓扑活性。LTRs是病毒整合酶将病毒DNA整合到宿主基因组中的必需位点。因此，我们研究了MAP30和GAP31对HIV-1整合酶的影响。我们报告称，这两种抗病毒剂均表现出对HIV-1整合酶的剂量依赖性抑制作用。在整合酶催化的所有三个特定反应中均观察到抑制作用，即3'加工（从病毒底物上特异性切割二核苷酸GT）、链转移（整合）和“解离”（链转移的逆转）。通过使用与HIV LTR的U3和U5区域序列相对应的寡核苷酸底物来研究抑制作用。在存在20 ng病毒底物、50 ng靶底物和4 microM整合酶的情况下，在整合酶和抗病毒蛋白等摩尔浓度时实现了完全抑制，EC50值约为1 microM。病毒DNA整合到宿主染色体中是逆转录病毒（包括艾滋病病毒）复制周期中的关键步骤。MAP30和GAP31对HIV-1整合酶的抑制表明，阻碍病毒DNA整合可能在这些植物蛋白的抗HIV活性中起关键作用。
