新型HIV-1 gp41融合抑制剂CP32M的构效关系研究

Structure-activity relationships of novel HIV-1 gp41 fusion peptide CP32M

目的研究新型融合多肽CP32M中VEWNEMT序列的长短、残基的极性及其他部位残基的极性对其抑制gp41融合活性的影响。方法在多肽CP32M的基础上,通过对前7个氨基酸序列进行截取、部分替换、全部替换及改变其他位置氨基酸残基的极性设计合成系列多肽,测定多肽抑制HIV-1融合活性。应用圆二色谱、分子排阻色谱测定多肽与N36的结合功能。结果截取、替换氨基酸后的肽抑制gp41融合的活性都不同程度降低,与N36结合形成六束螺旋的能力减弱。在CP32M中部及C端i与i+4位置引入Lys增加Glu-Lys离子对作用后,肽活性降低。用C34的C端氨基酸序列NEKDLLE及可与gp120结合的序列RINNIPWSEAM置换QIWNNMT后,多肽仍有很高活性。结论片段VEWNEMT是关键片段,其中VE及MT是关键功能氨基酸。其他片段替代该片段后仍有较强活性,也与N36形成螺旋结构,提示该片段含有共性结合区。

Objective To probe the effect of length, electric charge and fragment replacement of the key domain VEWNEMT and other residues in CP32M on its inhibitory activity to HIV-1 gp41 fusion. Methods Based on CP32M, a series of polypeptides of varied lengths and with electric charges and other functional fragments were designed and synthe- sized. The anti-HIV-1 activities were tested using HIV-1 m B virus, and interaction with N36 was determined by circular di- chroism spectrum and size-exclusion HPLC. Results Truncation and partial residue replacement in the fragment VEWNEMT or introduction of i to i ＋ 4 Glu-Lys ion pair interaction in the center or at C terminus of CP32M resulted in a decrease in the anti-H1V-1 activity of glM1 and the content of α-helix. The substitution of VEWNEMT by the fragment NEKDLLE derived from C terminus of C34 and a gpl20 binding peptide RINNIPWSEAM rescued the inhibitory activity. Conclusion VEWNEMT is the key fragment for CP32M, and residues VE and MT are crucial functional amino acids. The replacement of VEWNEMT by other functional domain retains high anti-HIV-1 activity and high content of helical structure, suggesting that this fragment contains a commons binding area.