HCV NS3 N末端部分氨基酸缺失对NS3/NS3与NS3/NS4A分子间相互作用的影响

目的旨在弄清ＮＳ３参与分子间相互作用的确切区段，为研究针对ＮＳ３的抗ＨＣＶ寡肽小分子药物的设计提供依据。方法参照ＨＣＶ中国河北株序列设计ＮＳ３引物，将其Ｎ末端的前１５个和前３０个氨基酸分别缺失掉。然后用酵母双杂交系统检测ＮＳ３／ＮＳ３及ＮＳ３／ＮＳ４Ａ分子间相互作用强度在缺失前后的变化，从而判明ＮＳ３Ｎ末端氨基酸在分子间相互作用中的意义。核苷酸序列分析采用ＡｐｐｌｉｅｄＢｉｏｓｙｓｔｅｍ３７３Ａ型自动测序仪。结果ＮＳ３Ｎ末端氨基酸缺失前后，ＮＳ３／ＮＳ３分子间及ＮＳ３／ＮＳ４Ａ分子间相互作用的强度相差有显著性（Ｐ＜０．０１），但缺失１５个氨基酸和缺失３０个氨基酸对上述相互作用强度的影响差异无显著性（Ｐ＞０．０５）。结论ＮＳ３Ｎ末端的１～３０个氨基酸在ＮＳ３／ＮＳ３及ＮＳ３／ＮＳ４Ａ分子间相互作用中有一定意义，其Ｎ末端前１５个氨基酸（ＡＰＩＴＡＹＳＱＱＴＲＧＬＬＧ）对于分子间相互作用更为关键。本研究结果将为抗ＮＳ３丝氨酸蛋白酶活性的寡肽抑制物的研究打下基础，并为抗ＨＣＶ的寡肽小分子药物的设计提供依据

The influence of HCV N terminal deletion on the molecular interactions betweem NS3/NS3 and NS3/NS4A

Objective The formation of NS3 serine protease crystal, NS3/NS4A complexity, and the results of two hybrid detection of NS3 and NS4A confirm the reality of interaction between NS3 and NS3, between NS3 and NS4A as well. But the precise domain of NS3, directly participated in the interactions, is not known now. This study is aimed at locating the domains directly participated in molecular interactions of NS3/NS3 and NS3/NS4A, and providing some valuable references to the research of anti HCV oligopeptide drug,which inhibits NS3 serine protease activity. Methods In designing NS3 primers, the sequences encoding the first fifteen and thirty amino acids of NS3 N terminal were deleted respectively. By comparing the strength between NS3/NS3 and NS3/NS4A molecular interaction, pre and post deletion the function of amino acids of NS3 N terminal in molecular interaction was analyzed. The applied biosystem 373A sequencer was used for DNA sequencing. Results The pre and post deletion interaction strength difference between NS3/NS3 and NS3/NS4A was significant( P <0.01), but the difference between 15 amino acids deletion and 30 amino acids deletion was insignificant( P >0.05). Conclusions Our study suggests that the first thirty amino acids are important in NS3/NS3 and NS3/NS4A interaction, and the first fifteen oligopeptides(APITAYSQQTRGLLG), located at N terminus of NS3, are more critical. This oligopeptides may be useful in designing the small molecule inhibitor of NS3 serine protease activity.