Chernomordik L, Chanturiya A N, Suss-Toby E, Nora E, Zimmerberg J
Laboratory of Theoretical and Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
J Virol. 1994 Nov;68(11):7115-23. doi: 10.1128/JVI.68.11.7115-7123.1994.
The peptide fragment of the carboxy-terminal region of the human immunodeficiency virus (HIV) transmembrane protein (gp41) has been implicated in T-cell death. This positively charged, amphipathic helix (amino acids 828 to 848) of the envelope protein is located within virions or cytoplasm. We studied the interaction of the isolated, synthetic amphipathic helix of gp41 with planar phospholipid bilayer membranes and with Sf9 cells using voltage clamp, potentiodynamic, and single-cell recording techniques. We found that the peptide binds strongly to planar membranes, especially to the negatively charged phosphatidylserine bilayer. In the presence of micromolar concentrations of peptide sufficient to make its surface densities comparable with those of envelope glycoprotein molecules in HIV virions, an increase in bilayer conductance and a decrease in bilayer stability were observed, showing pore formation in the planar lipid bilayers. These pores were permeable to both monovalent and divalent cations, as well as to chloride. The exposure of the inner leaflet of cell membranes to even 25 nM peptide increased membrane conductance. We suggest that the carboxy-terminal fragment of the HIV type 1 envelope protein may interact with the cell membrane of infected T cells to create lipidic pores which increase membrane permeability, leading to sodium and calcium flux into cells, osmotic swelling, and T-cell necrosis or apoptosis.
人类免疫缺陷病毒（HIV）跨膜蛋白（gp41）羧基末端区域的肽片段与T细胞死亡有关。包膜蛋白的这种带正电荷的两亲性螺旋（氨基酸828至848）位于病毒颗粒或细胞质内。我们使用电压钳、电位动力学和单细胞记录技术研究了分离的、合成的gp41两亲性螺旋与平面磷脂双层膜以及Sf9细胞的相互作用。我们发现该肽与平面膜强烈结合，尤其是与带负电荷的磷脂酰丝氨酸双层膜结合。在微摩尔浓度的肽存在下，其表面密度足以与HIV病毒颗粒中的包膜糖蛋白分子的表面密度相当，观察到双层膜电导增加和双层膜稳定性降低，表明在平面脂质双层膜中形成了孔。这些孔对单价和二价阳离子以及氯离子均具有通透性。细胞膜内小叶即使暴露于25 nM的肽也会增加膜电导。我们认为，HIV-1包膜蛋白的羧基末端片段可能与受感染T细胞的细胞膜相互作用，形成脂质孔，从而增加膜通透性，导致钠和钙流入细胞，引起渗透性肿胀以及T细胞坏死或凋亡。
