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HIVWT和HIVV2E这 2个多肽分别代表HIV 1gp41N末端由 2 3个氨基酸组成的融合肽及其第 2位的突变体 (Val→Glu) .采用多种方法研究了HIVWT和HIVV2E与酸性和中性脂膜作用时的结构 功能关系 .结果表明 ,HIVWT和HIVV2E具有相同的构象特点及构象变化趋势但功能却完全不同 :HIVWT主要采取α helix构象和酸性POPG脂膜作用并引起膜融合及膜稳定性的破坏 ,分子中的Phe残基可插入到POPG脂双层的疏水核心 ;HIVV2E也主要采取α helix构象和POPG脂膜作用但不引起膜融合和膜稳定性的破坏 ,分子中的Phe残基的位置接近POPG脂膜的表面 .HIVWT和HIVV2E与中性POPC脂膜作用时的主要构象均为 β sheet,并且都不能引起POPC脂膜相互融合和膜稳定性的破坏 ,分子中Phe残基的位置都接近POPC脂膜的表面 .以上结果证明 ,融合肽N末端的疏水性以及与膜脂相互作用时所采取的二级结构及插膜深度对融合肽功能的发挥起决定作用
The HIVWT and HIVV2E polypeptides represent the fusion peptide consisting of 23 amino acids at the HIV 1 gp41 N terminus and the mutant at position 2 (Val → Glu), respectively. HIVWT and HIVV2E were studied in combination with acidic and neutral lipids The results showed that both HIVWT and HIVV2E had the same conformational characteristics and conformational trends but completely different functions: HIVWT mainly adopted α helix conformation and acidic POPG lipid membrane and caused membrane fusion and membrane stability The Phe residues in the molecule can be inserted into the hydrophobic core of the POPG lipid bilayer. HIVV2E also mainly adopts the α helix conformation and the POPG lipid membrane but does not cause the destruction of membrane fusion and membrane stability. The Phe residues in the molecule Located close to the surface of the POPG lipid membrane.HIVWT and HIVV2E and the neutral POPC lipid membrane role in the main conformation are β sheet, and none of the POPC lipid membrane caused by mutual fusion and membrane stability damage, the location of Phe residues in the molecule Are close to the surface of the POPC lipid membrane.The above results demonstrate that the hydrophobicity of the N-terminus of the fusion peptide and the secondary structure and the depth of the intercalation taken upon interaction with the membrane lipids exert the function of the fusion peptide Decisive role