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RNase H (rnase + h)
Selected AbstractsDouble Cyclization of Bis(,-hetarylmethyl)amino Esters to Optically Active Bridged N-Heterocycles of HIV-Inhibiting ActivityEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2004Heike Faltz Abstract Anellated 1-azabicyclo[3.3.1]nonanes 6 were synthesized by several routes starting from natural ,-amino esters 2 and o -haloaryl- or o -bromohetarylmethyl bromides 1. N -Alkylation of the starting amino esters to 5 and 3 was followed by halogen/lithium exchange and double cyclization. The cyclization products 6 exhibit interesting inhibition of RNase H and DNA-polymerase activity of reverse transcriptase (RT) of HIV-1 at concentrations where human cellular DNA polymerases are not affected. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Inhibitory effects of Korean plants on HIV-1 activitiesPHYTOTHERAPY RESEARCH, Issue 6 2001Byung Sun Min Abstract In the search for novel anti-human immunodeficiency virus type 1 (anti-HIV-1) agents from natural sources, 49 MeOH extracts of Korean plants were screened for their inhibitory effects against RNA-dependent DNA polymerase (RT) and ribonuclease H (RNase H) activities of HIV-1 reverse transcriptase and HIV-1 protease, and anti-HIV-1 activity. Regarding the HIV-1 reverse transcriptase, Agrimonia pilosa (whole plant), Cornus kousa (stem and leaf), Limonium tetragonum (root) and Mallotus japonicus (stem) showed significant inhibitory activity on RT activity with 50% inhibitory activity (IC50) of 8.9, 6.3, 7.5 and 11.9,µg/mL, respectively, whereas Agrimonia pilosa was also active against RNase H activity (IC50,=,98.4,µg/mL). Four plants, namely Agrimonia pilosa (whole plant), Atractylodes japonica (root), Clematis heracleifolia (whole plant) and Syneilesis palmata (whole plant), were appreciably active (<35%) against recombinant HIV-1 protease at a concentration of 100,µg/mL. Crinum asiaticum var. japonicum (root) showed significant anti-HIV-1 activity (ED50,=,12.5,µg/mL) with a favourable SI value of 16. Copyright © 2001 John Wiley & Sons, Ltd. [source] Contributions of folding cores to the thermostabilities of two ribonucleases HPROTEIN SCIENCE, Issue 2 2002Srebrenka Robic Abstract To investigate the contribution of the folding cores to the thermodynamic stability of RNases H, we used rational design to create two chimeras composed of parts of a thermophilic and a mesophilic RNase H. Each chimera combines the folding core from one parent protein and the remaining parts of the other. Both chimeras form active, well-folded RNases H. Stability curves, based on CD-monitored chemical denaturations, show that the chimera with the thermophilic core is more stable, has a higher midpoint of thermal denaturation, and a lower change in heat capacity (,Cp) upon unfolding than the chimera with the mesophilic core. A possible explanation for the low ,Cp of both the parent thermophilic RNase H and the chimera with the thermophilic core is the residual structure in the denatured state. On the basis of the studied parameters, the chimera with the thermophilic core resembles a true thermophilic protein. Our results suggest that the folding core plays an essential role in conferring thermodynamic parameters to RNases H. [source] An RNase H-Assisted Fluorescent Biosensor for AptamersCHEMBIOCHEM, Issue 12 2007Dae-Ro Ahn Dr. Recycling program. A signal amplification strategy was established for aptamer-based molecular recognition of thrombin with concomitant release of a single-stranded guard-DNA (g-DNA). The g-DNA then bound to F-RNA-Q, which contained a fluorophore and quencher. The fluorescence-quenched RNA was degraded by using RNase H to give a fluorescence signal, and the undamaged g-DNA was recycled to yield fluorescence amplification. [source] | ||||||||||