Inhibition of the Human Immunodeficiency Virus Type 1 Integrase by Guanosine Quartet Structures

详细信息    查看全文

• 作者：Abhijit Mazumder ; Nouri Neamati ; Joshua O. Ojwang ; Sanjay Sunder ; Robert F. Rando ; and Yves Pommier
• 刊名：Biochemistry
• 出版年：1996
• 出版时间：October 29, 1996
• 年：1996
• 卷：35
• 期：43
• 页码：13762 - 13771
• 全文大小：530K
• 年卷期：v.35,no.43(October 29, 1996)
• ISSN：1520-4995

文摘

An oligonucleotide (T30177) composed entirely of deoxyguanosineand thymidine haspreviously been shown to fold upon itself in the presence of potassiuminto a highly stable four-strandedDNA structure containing two stacked deoxyguanosine quartets (G4s).T30177 also protects host cellsfrom the cytopathic effects of human immunodeficiency virus type 1(HIV-1). We report that this G4oligonucleotide is the most potent inhibitor of HIV-1 integraseidentified to date, with IC₅₀ values in thenanomolar range. Both the number of quartets formed and thesequence of the loops between the quartetsare important for optimal activity. T30177 binds to HIV-1integrase without being processed and blocksthe binding of the normal viral DNA substrate to the enzyme. Thenormal DNA substrate was not ableto compete off T30177 binding to HIV-1 integrase, indicating a tightbinding of G4s to the enzyme.Experiments with truncated HIV-1 integrases indicate that theN-terminal region containing a putativezinc finger is required for inhibition by T30177 and that T30177 bindsbetter to full-length or deletionmutant integrases containing the zinc finger region than to a deletionmutant consisting of only the centralcatalytic domain. The N-terminal region of integrase alone is ableto bind efficiently to T30177, but notthe linear viral DNA substrate, in the presence of zinc. Hence,G4s represent the first class of compoundsthat inhibit HIV-1 integrase by interacting with the enzyme N-terminaldomain. The greater inhibitorypotency of T30177 in buffer containing magnesium versus manganesesuggests that divalent metal ioncoordination along the phosphodiester backbone may play a role in theinhibitory activity. T30177 inhibitedHIV-2 integrase with similar potency as HIV-1 but inhibited feline andsimian immunodeficiency virusintegrases at higher concentrations, suggesting selectivity can beachieved. We propose that novel AIDStherapies could be based upon guanosine quartets as inhibitors of HIV-1integrase.