Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: Comparative biochemical analysis of recombinant reverse transcriptase enzymes of HIV-1 subtype B and subtype C. | Xu et al. Retrovirology 2010 7 80 http content 7 1 80 RETR0VIR0L0GY RESEARCH Open Access Comparative biochemical analysis of recombinant reverse transcriptase enzymes of HIV-1 subtype B and subtype C 11 1 11 Hong-Tao Xu Yudong Quan Eugene Asahchop Maureen Oliveira Daniella Moisi Mark A Wainberg Abstract Background HIV-1 subtype C infections account for over half of global HIV infections yet the vast focus of HIV-1 research has been on subtype B viruses which represent less than 12 of the global pandemic. Since HIV-1 reverse transcriptase RT is a major target of antiviral therapy and since differential drug resistance pathways have been observed among different HIV subtypes it is important to study and compare the enzymatic activities of HIV-1 RT derived from each of subtypes B and C as well as to determine the susceptibilities of these enzymes to various RT inhibitors in biochemical assays. Methods Recombinant subtype B and C HIV-1 RTs in heterodimeric form were purified from Escherichia coli and enzyme activities were compared in cell-free assays. The efficiency of - ssDNA synthesis was measured using gelbased assays with HIV-1 PBS RNA template and tRNA3Lys as primer. Processivity was assayed under single-cycle conditions using both homopolymeric and heteropolymeric RNA templates. Intrinsic RNase H activity was compared using 5 -end labeled RNA template annealed to 3 -end recessed DNA primer in a time course study in the presence and absence of a heparin trap. A mis-incorporation assay was used to assess the fidelity of the two RT enzymes. Drug susceptibility assays were performed both in cell-free assays using recombinant enzymes and in cell culture phenotyping assays. Results The comparative biochemical analyses of recombinant subtype B and subtype C HIV-1 reverse transcriptase indicate that the two enzymes are very similar biochemically in efficiency of tRNA-primed - ssDNA synthesis processivity fidelity and RNase H activity and that