unprocessed viral dna could be the primary target of the hiv-1 integrase inhibitor raltegravir未加工的病毒dna可能是hiv - 1整合酶抑制剂raltegravir的主要目标.pdf

Unprocessed Viral DNA Could Be the Primary Target of the HIV-1 Integrase Inhibitor Raltegravir 1,2 1 ´ 1 2 2 Farah F. Ammar , Safwat Abdel-Azeim , Loussinee Zargarian , Zeina Hobaika , Richard G. Maroun , Serge Fermandjian1* ´ ´ ´ ´ ´ 1 LBPA, UMR8113 du CNRS, Ecole Normale Superieure de Cachan, Cedex, Cachan, France, 2 Unite de Biochimie, Departement SVT, Faculte des Sciences, Universite Saint- Joseph, CST-Mar Roukoz, Beyrouth, Liban Abstract Integration of HIV DNA into host chromosome requires a 39-processing (39-P) and a strand transfer (ST) reactions catalyzed by virus integrase (IN). Raltegravir (RAL), commonly used in AIDS therapy, belongs to the family of IN ST inhibitors (INSTIs) acting on IN-viral DNA complexes (intasomes). However, studies show that RAL fails to bind IN alone, but nothing has been reported on the behaviour of RAL toward free viral DNA. Here, we assessed whether free viral DNA could be a primary target for RAL, assuming that the DNA molecule is a receptor for a huge number of pharmacological agents. Optical spectroscopy, molecular dynamics and free energy calculations, showed that RAL is a tight binder of both processed and unprocessed LTR (long terminal repeat) ends. Complex formation involved mainly van der Waals forces and was enthalpy driven. Dissociation constants (Kds) revealed that RAL affinity for unbound LTRs was stronger than for bound LTRs. Moreover, Kd value for binding of RAL to LTRs and IC50 value (half concentration for inhibition) were in same range, suggesting that RAL binding to DNA and ST inhibition are