The 2F5 epitope is helical in the HIV-1 entry inhibitor T-20
The 2F5 epitope is helical in the HIV-1 entry inhibitor T-20
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DOI：
10.1021/bi0509245
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发表时间：
2005-10-18
期刊：
影响因子：
2.9
通讯作者：
Anglister, J
中科院分区：
文献类型：
--
作者：
Biron, Z;Khare, S;Anglister, J
HIV-1包膜糖蛋白gp 41负责病毒与宿主细胞的融合。融合过程以及gp 41的完整结构还没有完全了解。HIV-1融合的最强抑制剂之一是一种名为T-20，gp 41（（638-673））的36个残基的肽（Fuzeon，也称为Enfuvirtide或DP-178;残基根据HXB 2 gp 160变体编号），现在用作抗HIV-1。药该肽还含有分别代表广泛中和人单克隆抗体2175和4 E10的完全或部分识别表位的免疫原性序列。由于其疏水性，T-20倾向于在水中以高浓度聚集，因此该分子在水溶液中的结构先前尚未确定。我们表达了一个均匀的C-13/N-15标记的42个残基的肽NN-T-20-NITN（gp 41（636-677）），并用异源二维和三维NMR方法确定了它的结构。由于额外的gp 41-天然亲水性残基，NN-T-20-NITN溶于水，首次能够在接近生理条件下测定其二级结构。我们的研究结果表明，NN-T-20-NITN肽是由一个主要是非结构化的N-末端区域和一个螺旋区域开始在T-20的中心，并向C-末端延伸。螺旋区在各种条件下被发现，并且在13个残基的肽gp 41（659-671）中也被观察到。我们认为，这种螺旋构象是保持在大多数不同的三级结构的gp 41包膜蛋白的过程中形成的病毒融合。因此，gp 41的免疫原性和Fuzeon的抑制特性的重要因素可能是这些多肽中的特定序列呈现螺旋结构的倾向。
The HIV-1 envelope glycoprotein gp41 is responsible for viral fusion with the host cell. The fusion process, as well as the full structure of gp41, is not completely understood. One of the strongest inhibitors of HIV-1 fusion is a 36-residue peptide named T-20, gp41((638-673)) (Fuzeon, also called Enfuvirtide or DP-178; residues are numbered according to the HXB2 gp160 variant) now used as an anti HIV-1. drug. This peptide also contains the immunogenic sequences that represent the full or partial recognition epitope for the broadly neutralizing human monoclonal antibodies 2175 and 4E10, respectively. Due to its hydrophobicity, T-20 tends to aggregate at high concentrations in water, and therefore the structure of this molecule in aqueous solution has not been previously determined. We expressed a uniformly C-13/N-15-labeled 42-residue peptide NN-T-20-NITN (gp41(636-677)) and used heteronuclear 2D and 3D NMR methods to determine its structure. Due to the additional gp41-native hydrophilic residues, NN-T-20-NITN dissolved in water, enabling for the first time determination of its secondary structure at near physiological conditions. Our results show that the NN-T-20-NITN peptide is composed of a mostly unstructured N-terminal region and a helical region beginning at the center of T-20 and extending toward the C-terminus. The helical region is found under various conditions and has been observed also in a 13-residue peptide gp41(659-671). We suggest that this helical conformation is maintained in most of the different tertiary structures of the gp41 envelope protein that form during the process of viral fusion. Accordingly, an important element of the immunogenicity of gp41 and the inhibitory properties of Fuzeon may be the propensity of specific sequences in these polypeptides to assume helical structures.