RESUMO
Human immunodeficiency virus type 1 (HIV-1) integrase (IN) is an essential enzyme in the life cycle of the retrovirus, responsible for catalysing the insertion of the viral genome into the host cell chromosome. For this reason it provides an attractive target for antiviral drug design. We synthesized a series of novel thiazole (Tz)-containing oligopeptides (TCOs; oligo-1,3-thiazolecarboxamides), specifically interacting within the minor groove of DNA. The oligocarboxamide derivatives contained 1-4 Tz rings and different N- and C-terminal groups. The effect of these oligocarboxamides on the HIV-1 IN-catalysed reaction was investigated. Some of the compounds were able to inhibit the reaction. The inhibitory effect of the TCOs increased with the number of Tz units. The structure of various additional positively and/or negatively charged groups attached to the N- and C-termini of TCOs had a pronounced effect on their interaction with the DNA substrate complexed to IN. Modified TCOs having a better affinity for this complex should provide a rationale for the design of drugs targeting the integration step.
Assuntos
DNA Viral/efeitos dos fármacos , Inibidores de Integrase de HIV/farmacologia , HIV-1/enzimologia , Tiazóis/farmacologia , Amidas/química , DNA Viral/metabolismo , Integrase de HIV/metabolismo , Inibidores de Integrase de HIV/química , Inibidores de Integrase de HIV/metabolismo , Ligantes , Espectroscopia de Ressonância Magnética , Proteínas Recombinantes/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Tiazóis/química , Tiazóis/metabolismoRESUMO
Retroviral integrase (IN) catalyzes the integration of double-stranded viral DNA into the host cell genome. The reaction can be divided in two steps: 3'-end processing and DNA strand transfer. Here we studied the effect of short oligonucleotides (ODNs) on human immunodeficiency virus type 1 (HIV-1) IN. ODNs were either specific, with sequences representing the extreme termini of the viral long terminal repeats, or nonspecific. All ODNs were found to competitively inhibit the processing reaction with Ki values in the nM range for the best inhibitors. Our studies on the interaction of IN with ODNs also showed that: (i) besides the 3'-terminal GT, the interaction of IN with the remaining nucleotides of the 21-mer specific sequence was also important for an effective interaction of the enzyme with the substrate; (ii) in the presence of specific ODNs the activity of the enzyme was enhanced, a result which suggests an ODN-induced conformational change of HIV-1 IN.
