銀奈米顆粒、HIV-1蛋白酶與特定肽鍵交互作用

Abstract

高效能抗愛滋病毒治療，又稱雞尾酒療法，為現今最常見的愛滋病毒治療方法。根據聯合國愛滋病署的報導，因高效能抗愛滋病毒治療的廣泛使用及其極佳的治療效果，感染愛滋病毒的患者及愛滋病毒相關死率在近年來大幅下滑。由於此療法無法完全移除患者體內的愛滋病毒，在長期服用的狀況下可能會產生一個嚴重的問題 —— 抗藥性，進而逐漸降低此療法的療效。因此，在目前醫療技術發達的時代，研發一種不會產生抗藥性的愛滋病治療方法是及其需要的。 在不同第一型人類免疫缺陷病毒(HIV-1)抑制劑中，HIV-1蛋白酶抑制劑不僅能抑制HIV-1蛋白酶的活動外，通常也可以用來抑制複製活動；銀奈米顆粒在過往研究已指出能有效抑制HIV-1蛋白酶的活性。本實驗藉由自行合成的銀奈米顆粒(2-4 nm)、含有HIV-1蛋白酶剪切位置的合成胜肽和HIV-1蛋白酶間的相互作用，來測試銀奈米顆粒對HIV-1 蛋白酶的抑制效果。 實驗結果顯示，HIV-1蛋白酶剪切合成胜肽反應快於銀奈米顆粒吸附上合成胜肽的速率。唯有先將銀奈米顆粒附著在合成胜肽上，才能有效抑制HIV-1 蛋白酶對胜肽的剪切作用。

Highly Active Anti-Retroviral Therapy is the most efficient treatment for HIV in current technology. However, this therapy doesn’t kill the entire virus, which leads to a thorny problem: drug resistance. Therefore, developing a new medicine that can effectively treat HIV and won’t cause drug resistant without is an inevitable need. To inactive HIV several inhibitors are developed. Among them, protease inhibitors (PIs) can not only inactivate HIV-1 protease (HIV-1 PR) but also inhibit HIV replication process. According to the literature, silver nanoparticles (Ag NPs) with unique antiviral property has been proved that they can inhibit HIV-1 PR in vitro, but the mechanism is not clear. In this study, five peptides which have similar amino acid sequence to HIV’s polyprotein are synthesized. Ag NPs are used to bind with synthesized peptides and HIV-1 PR, respectively. No cleavage occurs when the synthesized peptide has glycine at P2´ position, which meets the report from literature. The MALDI spectra show that incubating Ag NPs with synthesized peptide can efficiently inhibit HIV-1 PR since no signal of residuals molecule weight are detected. With three different experiment methods, we can know the process of HIV-1 PR inhibition by Ag NPs. From the results, we can say that the interaction between HIV-1 PR and synthesized peptide is faster than the binding of Ag NPs with peptides. Moreover, forming Ag NPs – peptide complex, Ag NPs bind with synthesized peptide, can effectively inhibit HIV-1 PR.