02567nas a2200193 4500008004100000022001400041245012700055210006900182260008900251300001000340490000700350520178700357653002802144653002202172653001602194100001702210700001902227856012702246 2006 eng d a0882-401000aIdentification of a respiratory-type nitrate reductase and its role for survival of mycobacterium smegmatis in wayne model0 aIdentification of a respiratorytype nitrate reductase and its ro a24-28 OVAL RD, LONDON NW1 7DX, ENGLANDbACADEMIC PRESS LTD ELSEVIER SCIENCE LTDcAUG a90-950 v413 a

Nitrate reductase (NR) is found to be expressed in certain mycobacterium sp. whose link with the development of persistence is yet to be resolved. The present study demonstrates the action of selective inhibitors on NR as well as in the survival of Mycobacterium smegmatis using Wayne's model. During gradual shift down to anaerobic stage in Wayne's model, conversion of nitrate to nitrite became apparent in M. smegmatis. More than 97 percent inhibition was observed for the conversion of nitrate to nitrite by azide (0.05 mM) and thiocyanate (20 mM) in both whole-cell as well as its cell-free lysate, respectively. Under identical condition, chlorate (20 mM) inhibited nitrate reduction by 67 and 10 percent, respectively. At these concentrations, neither of azide, thiocyanate nor chlorate had any significant effect on cell growth under aerobic condition. In Wayne's culture model, thiocyanate and chlorate inhibited the growth of M. smegmatis by almost 2 logs at the same concentrations whereas azide inhibited by almost 1.75 log when added at the time of inoculation. Exposure of same culture at 96 h after inoculation in Wayne's model to these inhibitors showed 1.74, 1.95 and 2.37 log inhibition of viable cells with respect to azide, thiocyanate and chlorate. These findings further indicated that NR inhibitors kill the bacilli at anaerobic stage under the experimental condition mentioned. Metronidazole (MTZ) (2 mM) and Nitrofurantoin (NIT) (0.3 mM) reduced the cell number at both stages by < 0.7log. They did not have any effect on NR. Altogether, the results clearly indicate that NR-specific inhibitors could become more promising in killing the bacilli at anaerobic stage than the available conventional drugs. (c) 2006 Elsevier Ltd. All rights reserved.

10aMycobacterium smegmatis10anitrate reductase10aWayne model1 aKhan, Arshad1 aSarkar, Dhiman uhttps://library.ncl.res.in/content/identification-respiratory-type-nitrate-reductase-and-its-role-survival-mycobacterium-001568nas a2200265 4500008004100000022001400041245007600055210006900131260007400200300001200274490000700286520066600293653002000959653002100979653002201000653002501022100001601047700002901063700001901092700002601111700001901137700001701156700002601173856010301199 2007 eng d a0141-549200aNitrate reductase-mediated synthesis of silver nanoparticles from AgNO30 aNitrate reductasemediated synthesis of silver nanoparticles from aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcMAR a439-4450 v293 a

Synthesis of silver nanoparticles using alpha-NADPH-dependent nitrate reductase and phytochelatin in vitro has been demonstrated for the first time. The silver ions were reduced in the presence of nitrate reductase, leading to the formation of a stable silver hydrosol 10-25 nm diam. and stabilized by the capping peptide. The nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-Vis absorption. These studies will help in designing a rational enzymatic strategy for the synthesis of nanomaterials of different chemical composition, shapes and sizes as well as their separation.

10aCapping Peptide10aenzymatic method10anitrate reductase10asilver nanoparticles1 aKumar, Anil1 aAbyaneh, Majid, Kazemian1 aGosavi, S., W.1 aKulkarni, Sulabha, K.1 aPasricha, Renu1 aAhmad, Absar1 aKhan, Mohammad, Islam uhttps://library.ncl.res.in/content/nitrate-reductase-mediated-synthesis-silver-nanoparticles-agno302223nas a2200217 4500008004100000022001400041245016600055210006900221260007600290300001200366490000700378520134900385653003001734653001401764653003101778653002201809653000901831100001801840700001901858856012801877 2012 eng d a1087-057100aPotential use of nitrate reductase as a biomarker for the identification of active and dormant inhibitors of mycobacterium tuberculosis in a THP1 infection model0 aPotential use of nitrate reductase as a biomarker for the identi a2455 TELLER RD, THOUSAND OAKS, CA 91320 USAbSAGE PUBLICATIONS INCcAUG a966-9730 v173 a

The development of a macrophage-based, antitubercular high-throughput screening system could expedite discovery programs for identifying novel inhibitors. In this study, the kinetics of nitrate reduction (NR) by Mycobacterium tuberculosis during growth in Thp1 macrophages was found to be almost parallel to viable bacilli count. NR in the culture medium containing 50 mM of nitrate was found to be optimum on the fifth day after infection with M. tuberculosis. The signal-to-noise (S/N) ratio and Z-factor obtained from this macrophage-based assay were 5.4 and 0.965, respectively, which confirms the robustness of the assay protocol. The protocol was further validated by using standard antitubercular inhibitors such as rifampicin, isoniazid, streptomycin, ethambutol, and pyrazinamide, added at their IC90 value, on the day of infection. These inhibitors were not able to kill the bacilli when added to the culture on the fifth day after infection. Interestingly, pentachlorophenol and rifampicin killed the bacilli immediately after addition on the fifth day of infection. Altogether, this assay protocol using M. tuberculosis-infected Thp-1 macrophages provides a novel, cost-efficient, robust, and easy-to-perform screening platform for the identification of both active and hypoxic stage-specific inhibitors against tuberculosis.

10ahigh-throughput screening10ainhibitor10aMycobacterium tuberculosis10anitrate reductase10aTHP11 aSarkar, Sampa1 aSarkar, Dhiman uhttps://library.ncl.res.in/content/potential-use-nitrate-reductase-biomarker-identification-active-and-dormant-inhibitors-0