标题：Biochemical Characterization of Recombinant HIV-1 Reverse Transcriptase (rRT) as a Glycyrrhizin-Binding Protein and the CK-II-Mediated Stimulation of rRT Activity Potently Inhibited by Glycyrrhetinic Acid Derivative
摘要：By means of successive Mono Q and glycyrrhizin (GL)-affinity column chromatography (HPLC), recombinant HIV-1 RT (rRT) was purified to apparent homogeneity from the Superdex 200 pg fraction of the crude protein extract of E. coli BL21 transfected with pET 21a(+)/HIV-1 PR-RT. It was found that (i) rRT functioned as an effective phosphate acceptor for recombinant human casein kinase II (rhCK-II) in vitro; (ii) this phosphorylation was inhibited by anti-HIV-1 substances [a glycyrrhetinic acid derivative (oGA) and quercetin] and a high dose (100 μM) of GL; (iii) RNA-dependent DNA polymerase (RDDP) activity was stimulated about 2.5-fold after full phosphorylatioin of rRT by rhCK-II; and (iv) oGA as well as NCS-chromophore effectively prevented the CKI-II-mediated stimulation of RDDP activity. These results suggest that the anti-HIV-1 effect of oGA may be involved in the selective inhibition of the CK-II-mediated stimulation of HIV-1 RT at the cellular level.
