人类免疫缺陷病毒1型（HIV-1）通过其包膜糖蛋白（Env）介导侵入靶细胞。Env由受体特异性结合单位gp120和膜融合单位gp41组成。HIV-1的gp41可分为3个功能区：膜外区、跨膜区和膜内区。膜外区是病毒感染时膜融合的主要结构基础，跨膜区通过疏水残基使 Env 锚定在脂质膜上，膜内区则表现多重功能，参与病毒的感染、复制、装配等过程。膜内区的功能由其特定的结构域或基序完成，包括3个慢病毒裂解肽（LLP 1~3）、含Tyr基序(Y₇₁₂XXL和Y₈₀₂W₈₀₃)和双Leu基序（LL_855/856）等。病毒诱导的融合过程中，包含Kennedy表位在内的膜内区发生拓扑学改变，表明gp41的3个功能区之间存在相互作用。这些进展对了解HIV-1的感染、复制和致病机制，开发新的抗病毒药物具有重要意义。

Entrance of human immunodeficiency virus type 1 (HIV-1) into cells is mediated by envelope glycoprotein (Env) ，which contains a receptor-binding unit gp120 and a membrane-fusion unit gp41. HIV-1 gp41 consists of three major functional regions: ectodomain, membrane-spanning domain (MSD) and endodomain. The ectodomain is a structural basis for membrane fusion during viral infection; the hydrophobic residues of MSD anchor Env to the bilayer membrane; and the endodomain plays multiple functions in viral infection, replication and assembly. The most important motifs in the endodomain are three lentivirus lytic peptides (LLP 1-3), two Tyr-contained motifs (Y₇₁₂XXL and Y₈₀₂W₈₀₃), and a dileucine motif (LL_856/857). Additionally, the topological change of the endodomain including Kennedy epitope shows there are interactions among three regions of gp41. The progress in function-structure of gp41 not only improves the understanding to the replication and pathogenesis of HIV-1 but also provides some insights into the development of new antiviral drugs.