高效抗HIV-1膜融合多肽C22的光谱学研究

艾滋病已给人类社会和经济带来了巨大影响。文章以HIV-1膜融合糖蛋白gp41的C端序列为参照，设计合成了C22多肽的基因序列，经PCR放大以后，通过pTMHa30-51质粒转导进E.coli BL21 (DE3)中进行表达，纯化后得到了C22多肽，表达产物经SDS-PAGE电泳分析和质谱验证。结果表明：C22多肽具有很好热稳定性，良好的HIV-1入侵细胞抑制活性和水溶性，在实验浓度下对细胞无毒性。通过圆二色谱技术对C22的二级结构进行了检测，C22溶液在37 ℃条件下，α螺旋比例增加，而在80 ℃条件下，α螺旋比例则呈下降趋势。在不同pH值条件下，C22峰值变化较大，在向酸碱两性方向变化时，C22的α螺旋结构比例均相对有所减少，无规则卷曲增加，结构趋向松散。这也表明，在pH 6条件下，C22可以保持相对稳定的结构。该研究为此类多肽的光谱学性质研究和设计新的HIV-1治疗药物提供了理论基础。

Studies on the Spectral Characteristics of Efficient HIV-1 Fusion Inhibitor C22

Acquired immune deficiency syndrome (AIDS) is increasing its negative influences on human society and economy.In the present paper, HIV-1 cell fusion peptide inhibitor C22 was expressed and purified based on the C-terminal sequence of HIV-l membrane fusion glycoprotein gp41.The gene coding for C22 was totally synthesized using gp41 gene as a template and amplified by PCR.The cloned C22 gene was confirmed by restriction endonuclease and sequence analysis and then cloned into plasmid pTMHa30-51.The prepared plasmid was transformed into E.coli BL21 (DE3) and the expressing products were analyzed on SDS-PAGE and tested with mass spectrum.The results indicated that C22 showed high HIV-1 fusion inhibiting capacity, meanwhile, with good thermal stability and water-solubility, and showed no cell toxicity in tested concentrations.The spectral characteristics were tested with circular dichroism (CD).When treated at different temperature in solution condition, the content of α helix of C22 increased at 37 ℃ while decreased sharply at 80 ℃.The peak value changed significantly with different pH values.The content of α helix of C22 decreased as pH varied toward acid and alkali and the random coiling increased, which led to a relaxed structure.This result indicated that the C22 structure is stable with pH 6.This research may provide a theoretic foundation for the new type HIV-1 peptide inhibitor designing and spectral characteristics study.