02628nas a2200265   4500008004100000022001400041245019800055210006900253260007400322300001400396490000700410520155800417653003201975653002202007653002602029653002202055100002002077700001802097700001802115700002402133700003202157700002202189700002702211856012402238       2013                        eng d  a0301-485100aFunctional characterization, homology modeling and docking studies of beta-glucosidase responsible for bioactivation of cyanogenic hydroxynitrile glucosides from Leucaena leucocephala (subabul)0 aFunctional characterization homology modeling and docking studie  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcFEB  a1351-13630 v403 a<p>Glycosyl hydrolase family 1 beta-glucosidases are important enzymes that serve many diverse functions in plants including defense, whereby hydrolyzing the defensive compounds such as hydroxynitrile glucosides. A hydroxynitrile glucoside cleaving beta-glucosidase gene (Llbglu1) was isolated from Leucaena leucocephala, cloned into pET-28a (+) and expressed in E. coli BL21 (DE3) cells. The recombinant enzyme was purified by Ni-NTA affinity chromatography. The optimal temperature and pH for this beta-glucosidase were found to be 45 A degrees C and 4.8, respectively. The purified Llbglu1 enzyme hydrolyzed the synthetic glycosides, pNPGlucoside (pNPGlc) and pNPGalactoside (pNPGal). Also, the enzyme hydrolyzed amygdalin, a hydroxynitrile glycoside and a few of the tested flavonoid and isoflavonoid glucosides. The kinetic parameters K (m) and V (max) were found to be 38.59 mu M and 0.8237 mu M/mg/min for pNPGlc, whereas for pNPGal the values were observed as 1845 mu M and 0.1037 mu M/mg/min. In the present study, a three dimensional (3D) model of the Llbglu1 was built by MODELLER software to find out the substrate binding sites and the quality of the model was examined using the program PROCHEK. Docking studies indicated that conserved active site residues are Glu 199, Glu 413, His 153, Asn 198, Val 270, Asn 340, and Trp 462. Docking of rhodiocyanoside A with the modeled Llbglu1 resulted in a binding with free energy change (Delta G) of -5.52 kcal/mol on which basis rhodiocyanoside A could be considered as a potential substrate.</p>10aGlycosyl hydrolase family 110ahomology modeling10aLeucaena leucocephala10aMolecular docking1 aShaik, Noor, M.1 aMisra, Anurag1 aSingh, Somesh1 aFatangare, Amol, B.1 aRamakumar, Suryanarayanarao1 aRawal, Shuban, K.1 aKhan, Bashir, Mohammad  uhttps://library.ncl.res.in/content/functional-characterization-homology-modeling-and-docking-studies-beta-glucosidase-002540nas a2200277   4500008004100000022001400041245011000055210006900165260007900234300001200313490000800325520151400333653001401847653001801861653002401879653002301903653005501926653002301981100001802004700002802022700002602050700002702076700000902103700002702112856012302139       2013                        eng d  a0273-228900aFunctional characterization of a flavonoid glycosyltransferase gene from withania somnifera (Ashwagandha)0 aFunctional characterization of a flavonoid glycosyltransferase g  a999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USAbHUMANA PRESS INCcJUN  a729-7410 v1703 a<p>Glycosylation of flavonoids is mediated by family 1 uridine diphosphate (UDP)-dependent glycosyltransferases (UGTs). Until date, there are few reports on functionally characterized flavonoid glycosyltransferases from Withania somnifera. In this study, we cloned the glycosyltransferase gene from W. somnifera (UGT73A16) showing 85-92 % homology with UGTs from other plants. UGT73A16 was expressed as a His(6)-tagged fusion protein in Escherichia coli. Several compounds, including flavonoids, were screened as potential substrates for UGT73A16. HPLC analysis and hypsochromic shift indicated that UGT73A16 transfers a glucose molecule to several different flavonoids. Based on kinetic parameters, UGT73A16 shows more catalytic efficiency towards naringenin. Here, we explored UGT73A16 of W. somnifera as whole cell catalyst in E. coli. We used flavonoids (genistein, apigenin, kaempferol, naringenin, biochanin A, and daidzein) as substrates for this study. More than 95 % of the glucoside products were released into the medium, facilitating their isolation. Glycosylation of substrates occurred on the 7- and 3-hydroxyl group of the aglycone. UGT73A16 also displayed regiospecific glucosyl transfer activity towards 3-hydroxy flavone compound, which is the backbone of all flavonols and also for a chemically synthesized compound, not found naturally. The present study generates essential knowledge and molecular as well as biochemical tools that allow the verification of UGT73A16 in glycosylation.</p>10aFlavonoid10aglycosylation10aGlycosyltransferase10aHypsochromic shift10aPlant secondary product glycosyltransferase (PSPG)10aWithania somnifera1 aSingh, Somesh1 aVishwakarma, Rishi., K.1 aKumar, R., J. Santosh1 aSonawane, Prashant, D.1 aRuby1 aKhan, Bashir, Mohammad  uhttps://library.ncl.res.in/content/functional-characterization-flavonoid-glycosyltransferase-gene-withania-somnifera-002294nas a2200253   4500008004100000022001400041245011800055210006900173260005700242300001400299490000700313520138200320653001301702653001501715653002401730653002301754100002601777700000901803700001801812700002701830700002401857700002701881856013201908       2013                        eng d  a0735-964000aFunctional characterization of a glucosyltransferase specific to flavonoid 7-O-glucosides from withania somnifera0 aFunctional characterization of a glucosyltransferase specific to  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcOCT  a1100-11080 v313 a<p>Flavonoids are a large class of phenylpropanoid-derived secondary metabolites, which are usually glycosylated by UDP-glycosyltransferases with one or more sugar groups. Here, we report the cloning and biochemical characterization of a flavonoid glycosyltransferase gene from Withania somnifera (WsGT), which is an important medicinal plant used in Ayurvedic formulations. Using PCR primers, designed for a highly conserved region of previously reported glycosyltransferases, we were able to isolate the corresponding fragment of the WsGT gene. Rapid amplification of cDNA ends (RACE) was then employed to isolate full-length cDNA, which had an open reading frame of 1,371 bp that encode for 456 amino acids. Phylogenetic analysis indicated that WsGT was similar to that of family 1 GT-B glycosyltransferase. Biochemical analysis revealed that WsGT interacts with UDP-glucose and was capable of regiospecifically glycosylating flavonoid-7-ols, such as apigenin, naringenin, luteolin, diadzein and genistein. Expression profiling studies showed that WsGT was highly expressed in young and mature leaves of W. somnifera. Furthermore, exposure to salicylic acid enhanced the expression of WsGT in the leaves and heat shock treatment resulted in decreased expression of WsGT after an initial increase. This may suggest the role of WsGT in response to abiotic/biotic stresses.</p>10aDiadzein10aFlavonoids10aGlycosyltransferase10aWithania somnifera1 aKumar, R., J. Santosh1 aRuby1 aSingh, Somesh1 aSonawane, Prashant, D.1 aVishwakarma, R., K.1 aKhan, Bashir, Mohammad  uhttps://library.ncl.res.in/content/functional-characterization-glucosyltransferase-specific-flavonoid-7-o-glucosides-withania-002009nas a2200205   4500008004100000022001400041245013400055210006900189260005700258300001200315490000700327520122100334100002701555700002301582700001801605700001601623700000901639700002701648856012801675       2013                        eng d  a0971-589400aMolecular characterization and differential expression studies of an oxidosqualene cyclase (OSC) gene of Brahmi (Bacopa monniera)0 aMolecular characterization and differential expression studies o  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcOCT  a547-5530 v193 a<p>Triterpenoid saponins are the class of secondary metabolites, synthesized via isoprenoid pathway. Oxidosqualene cyclases (OSCs) catalyzes the cyclization of 2, 3-oxidosqualene to various triterpene skeletons, the first committed step in triterpenoid biosynthesis. A full-length oxidosqualene cyclase cDNA from Bacopa monniera (BmOSC) was isolated and characterized. The open reading frame (ORF) of BmOSC consists of 2,292 bp, encoding 764 amino acid residues with an apparent molecular mass of 87.62 kDa and theoretical pI 6.21. It contained four QxxxxxW motifs, one Asp-Cys-Thr-Ala-Glu (DCTAE) motif which is highly conserved among the triterpene synthases and another MWCYCR motif involved in the formation of triterpenoid skeletons. The deduced amino acid sequence of BmOSC shares 80.5 % &amp; 71.8 % identity and 89.7 % &amp; 83.5 % similarity with Olea europaea mixed amyrin synthase and Panax notoginseng dammarenediol synthase respectively. Phylogenetic analysis revealed that BmOSC is closely related with other plant OSCs. Quantitative real-time PCR (qRT-PCR) data showed that BmOSC is expressed in all tissues examined with higher expression in stem and leaves as compared to roots and floral parts.</p>1 aVishwakarma, Rishi, K.1 aSonawane, Prashant1 aSingh, Somesh1 aKumari, Uma1 aRuby1 aKhan, Bashir, Mohammad  uhttps://library.ncl.res.in/content/molecular-characterization-and-differential-expression-studies-oxidosqualene-cyclase-osc02707nas a2200277   4500008004100000022001400041245015800055210006900213260005700282300001200339490000700351520166600358653003502024653002002059653002302079653002502102100002702127700000902154700001802163700002702181700002302208700001602231700002602247700002702273856012902300       2013                        eng d  a0735-964000aMolecular cloning, biochemical characterization, and differential expression of an acetyl-CoA C-acetyltransferase gene (AACT) of brahmi (Bacopa monniera)0 aMolecular cloning biochemical characterization and differential   a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJUN  a547-5570 v313 a<p>Bacopa monniera (Brahmi) is an important Indian medicinal herb found in wet damp and marshy places. It produces medicinally important compounds known as bacosides along with alkaloids like brahmine and herpestine. Bacosides are triterpenoid saponins and their biosynthesis takes place via the isoprenoid pathway starting with acetyl-CoA. Acetyl-CoA C-acetyltransferase (AACT; EC 2.3.1.9), also known as acetoacetyl-CoA thiolase (Thiolase II), catalyzes the condensation of two acetyl-CoA to form 4-C compound acetoacetyl-CoA. Acetoacetyl-CoA is an important starting molecule for biosynthesis of various metabolites. Here, we report the cDNA cloning and characterization of acetyl-CoA C-acetyltransferase gene from B. monniera. The full-length gene was isolated using a RACE PCR protocol. The cDNA encoding AACT was designated as BmAACT (FJ947159) revealed an ORF of 1,218 bp and 405 amino acids, and shares 80 % similarity with other plant AACTs. Phylogenetic analysis showed that BmAACT is related closely to other dicot plants AACTs. The BmAACT gene was over-expressed in Escherichia coli as a 6X His-tag fusion protein and purified to homogeneity by Ni-NTA and gel filtration chromatography. Activity of recombinant protein was confirmed by thiolytic cleavage of acetoacetyl-CoA in the presence of 5 mM Mg2+, showing K (m) and V (max) of 20.67 mu M and 96.21 mu mol/min, respectively, with high catalytic efficiency (k (cat) = 2.30 x 10(5) min(-1)). Quantitative real-time PCR analysis showed that the expression of BmAACT is tissue-specific, and accumulation of transcripts is greater in roots and petals, followed by sepals, stem, leaf and pedicel.</p>10aAcetyl-CoA C-acetyltransferase10aBacopa monniera10aIsoprenoid pathway10aTriterpenoid saponin1 aVishwakarma, Rishi, K.1 aRuby1 aSingh, Somesh1 aSonawane, Prashant, D.1 aSrivastava, Sameer1 aKumari, Uma1 aKumar, R., J. Santosh1 aKhan, Bashir, Mohammad  uhttps://library.ncl.res.in/content/molecular-cloning-biochemical-characterization-and-differential-expression-acetyl-coa-c-002183nas a2200289   4500008004100000022001400041245009500055210006900150260007300219300001000292490000700302520114300309653002601452653003001478653002401508653002201532653003001554653002501584100002301609700001801632700003201650700002301682700001801705700002501723700002701748856011801775       2013                        eng d  a0141-813000aProbing the active site of cinnamoyl CoA reductase 1 (Ll-CCRH1) from Leucaena leucocephala0 aProbing the active site of cinnamoyl CoA reductase 1 LlCCRH1 fro  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP  a33-380 v603 a<p>Lack of three dimensional crystal structure of cinnamoyl CoA reductase (CCR) limits its detailed active site characterization studies. Putative active site residues involved in the substrate/NADPH binding and catalysis for Leucaena leucocephala CCR (Ll-CCRH1; GenBank: DQ986907) were identified by amino acid sequence alignment and homology modeling. Putative active site residues and proximal H215 were subjected for site directed mutagenesis, and mutated enzymes were expressed, purified and assayed to confirm their functional roles. Mutagenesis of S136, Y170 and K174 showed complete loss of activity, indicating their pivotal roles in catalysis. Mutant S212G exhibited the catalytic efficiencies less than 10% of wild type, showing its indirect involvement in substrate binding or catalysis. R51G, D77G, F30V and I31N double mutants showed significant changes in K-m values, specifying their roles in substrate binding. Finally, chemical modification and substrate protection studies corroborated the presence Ser, Tyr, Lys, Arg and carboxylate group at the active site of Ll-CCRH1. (c) 2013 Elsevier B.V. All rights reserved.</p>10aChemical modification10aCinnamoyl CoA reductase 110aDocking simulations10ahomology modeling10aSite directed mutagenesis10aSubstrate protection1 aSonawane, Prashant1 aPatel, Krunal1 aVishwakarma, Rishi, Kishore1 aSrivastava, Sameer1 aSingh, Somesh1 aGaikwad, Sushama, M.1 aKhan, Bashir, Mohammad  uhttps://library.ncl.res.in/content/probing-active-site-cinnamoyl-coa-reductase-1-ll-ccrh1-leucaena-leucocephala-002607nas a2200253   4500008004100000022001400041245012100055210006900176260007400245300001400319490000700333520164700340653002001987653002402007653002402031653002402055653005402079100000902133700002602142700002702168700001802195700002702213856011302240       2014                        eng d  a0301-485100aMolecular cloning and characterization of genistein 4'-O-glucoside specific glycosyltransferase from Bacopa monniera0 aMolecular cloning and characterization of genistein 4Oglucoside   aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcJUL  a4675-46880 v413 a<p>Health related benefits of isoflavones such as genistein are well known. Glycosylation of genistein yields different glycosides like genistein 7-O-glycoside (genistin) and genistein 4'-O-glycoside (sophoricoside). This is the first report on isolation, cloning and functional characterization of a glycosyltransferase specific for genistein 4'-O-glucoside from Bacopa monniera, an important Indian medicinal herb. The glycosyltransferase from B. monniera (UGT74W1) showed 49 % identity at amino acid level with the glycosyltransferases from Lycium barbarum. The UGT74W1 sequence contained all the conserved motifs present in plant glycosyltransferases. UGT74W1 was cloned in pET-30b (+) expression vector and transformed into E. coli. The molecular mass of over expressed protein was found to be around 52 kDa. Functional characterization of the enzyme was performed using different substrates. Product analysis was done using LC-MS and HPLC, which confirmed its specificity for genistein 4'-O-glucoside. Immuno-localization studies of the UGT74W1 showed its localization in the vascular bundle. Spatio-temporal expression studies under normal and stressed conditions were also performed. The control B. monniera plant showed maximum expression of UGT74W1 in leaves followed by roots and stem. Salicylic acid treatment causes almost tenfold increase in UGT74W1 expression in roots, while leaves and stem showed decrease in expression. Since salicylic acid is generated at the time of injury or wound caused by pathogens, this increase in UGT74W1 expression under salicylic acid stress might point towards its role in defense mechanism.</p>10aBacopa monniera10aExpression analysis10aGlycosyltransferase10aImmuno-localization10aPlant secondary product glycosyltransferase motif1 aRuby1 aKumar, R., J. Santosh1 aVishwakarma, Rishi, K.1 aSingh, Somesh1 aKhan, Bashir, Mohammad  uhttps://library.ncl.res.in/content/molecular-cloning-and-characterization-genistein-4-o-glucoside-specific-002755nas a2200253   4500008004100000022001400041245012600055210006900181260007500250300001200325490000700337520179300344653002402137653002802161653001702189653001902206653002102225100002302246700003202269700001802301700002502319700002702344856013002371       2014                        eng d  a1053-050900aSteady state fluorescence studies of wild type recombinant cinnamoyl CoA reductase (Ll-CCRH1) and its active site mutants0 aSteady state fluorescence studies of wild type recombinant cinna  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGER/PLENUM PUBLISHERScMAY  a665-6730 v243 a<p>Fluorescence quenching and time resolved fluorescence studies of wild type recombinant cinnamoyl CoA reductase (Ll-CCRH1), a multitryptophan protein from Leucaena leucocephala and 10 different active site mutants were carried out to investigate tryptophan environment. The enzyme showed highest affinity for feruloyl CoA (K (a) = 3.72 x 10(5) M-1) over other CoA esters and cinnamaldehydes, as determined by fluorescence spectroscopy. Quenching of the fluorescence by acrylamide for wild type and active site mutants was collisional with almost 100 % of the tryptophan fluorescence accessible under native condition and remained same after denaturation of protein with 6 M GdnHCl. In wild type Ll-CCRH1, the extent of quenching achieved with iodide (f (a) = 1.0) was significantly higher than cesium ions (f (a) = 0.33) suggesting more density of positive charge around surface of trp conformers under native conditions. Denaturation of wild type protein with 6 M GdnHCl led to significant increase in the quenching with cesium (f (a) = 0.54), whereas quenching with iodide ion was decreased (f (a) = 0.78), indicating reorientation of charge density around trp from positive to negative and heterogeneity in trp environment. The Stern-Volmer plots for wild type and mutants Ll-CCRH1 under native and denatured conditions, with cesium ion yielded biphasic quenching profiles. The extent of quenching for cesium and iodide ions under native and denatured conditions observed in active site mutants was significantly different from wild type Ll-CCRH1 under the same conditions. Thus, single substitution type mutations of active site residues showed heterogeneity in tryptophan microenvironment and differential degree of conformation of protein under native or denatured conditions.</p>10aActive site mutants10aCinnamoyl CoA reductase10afluorescence10aLigand binding10aSolute quenching1 aSonawane, Prashant1 aVishwakarma, Rishi, Kishore1 aSingh, Somesh1 aGaikwad, Sushama, M.1 aKhan, Bashir, Mohammad  uhttps://library.ncl.res.in/content/steady-state-fluorescence-studies-wild-type-recombinant-cinnamoyl-coa-reductase-ll-ccrh1-002468nas a2200325   4500008004100000022001400041245016100055210006900216260005700285300001400342490000700356520130200363653001901665653002001684653003701704653002801741653002301769653002201792100002701814700001801841700002301859700001601882700001801898700000901916700002101925700002401946700002101970700002701991856012402018       2015                        eng d  a0735-964000ac Squalene synthase gene from medicinal herb bacopa monniera: molecular characterization, differential expression, comparative modeling, and docking studies0 ac Squalene synthase gene from medicinal herb bacopa monniera mol  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcDEC  a1675-16850 v333 a<p>The widespread pharmaceutically important triterpenoid saponins are synthesized via isoprenoid pathway. The formation of squalene is the key regulatory point in triterpene biosynthesis, catalyzed by squalene synthase (SQS). The present study deals with the detailed characterization of SQS by molecular, biochemical, and computational means from Bacopa monniera, an immensely important medicinal plant rich in triterpenoid saponin, bacosides. A full-length SQS gene was isolated from B. monniera, characterized as B. monniera squalene synthase (BmSQS) (1242 bp) encoding 414 amino acids. Deduced amino acid sequence of BmSQS showed highly conserved consensus aspartate-rich motifs (DXXXD) and catalytic site residues. Phylogenetic analysis showed that BmSQS belongs to dicot group having closest relationship with Salvia miltiorrhiza. Semiquantitative and real-time PCR studies showed that the BmSQS messenger RNA (mRNA) expression level was higher in vegetative parts (roots) as compared to floral parts. Methyl jasmonate induces the BmSQS mRNA expression in all tissues tested, while salicylic acid, cold, and salt induce much higher expression in roots. Homology modeling and docking simulations of BmSQS showed the pivotal roles of Asp77, Asp81, Asp213, Asp217, and Tyr168 in catalysis.</p>10aAbiotic stress10aBacopa monniera10aComparative modeling and docking10aDifferential expression10aIsoprenoid pathway10aSqualene synthase1 aVishwakarma, Rishi, K.1 aPatel, Krunal1 aSonawane, Prashant1 aKumari, Uma1 aSingh, Somesh1 aRuby1 aAbbassi, Shakeel1 aAgrawal, Dinesh, C.1 aTsay, Hsin-Sheng1 aKhan, Bashir, Mohammad  uhttps://library.ncl.res.in/content/c-squalene-synthase-gene-medicinal-herb-bacopa-monniera-molecular-characterization-002232nas a2200181   4500008004100000022001500041245010100056210006900157260000800226490000700234520156800241100001801809700002201827700002701849700002701876700002101903856012601924       2018                        eng d  a 0959-399300a Enhanced activity of Withania somnifera family-1 glycosyltransferase (UGT73A16) via mutagenesis0 aEnhanced activity of Withania somnifera family1 glycosyltransfer  cOCT0 v343 aThis work used an approach of enzyme engineering towards the improved production of baicalin as well as alteration of acceptor and donor substrate preferences in UGT73A16. The 3D model of Withania somnifera family-1 glycosyltransferase (UGT73A16) was constructed based on the known crystal structures of plant UGTs. Structural and functional properties of UGT73A16 were investigated using docking and mutagenesis. The docking studies were performed to understand the key residues involved in substrate recognition. In the molecular model of UGT73A16, substrates binding pockets are located between N- and C-terminal domains. Modeled UGT73A16 was docked with UDP-glucose, UDP-glucuronic acid (UDPGA), kaempferol, isorhamnetin, 3-hydroxy flavones, naringenin, genistein and baicalein. The protein-ligand interactions showed that His 16, Asp 246, Lys 255, Ala 337, Gln 339, Val 340, Asn 358 and Glu 362 amino acid residues may be important for catalytic activity. The kinetic parameters indicated that mutants A337C and Q339A exhibited 2-3 fold and 6-7 fold more catalytic efficiency, respectively than wild type, and shifted the sugar donor specificity from UDP-glucose to UDPGA. The mutant Q379H displayed large loss of activity with UDP-glucose and UDPGA strongly suggested that last amino acid residue of PSPG box is important for glucuronosylation and glucosylation and highly specific to sugar binding sites. The information obtained from docking and mutational studies could be beneficial in future to engineer this biocatalyst for development of better ones.1 aSingh, Somesh1 aPatel, Krunal, A.1 aSonawane, Prashant, D.1 aVishwakarma, Rishi, K.1 aKhan, Bashir, M.  uhttps://library.ncl.res.in/content/enhanced-activity-withania-somnifera-family-1-glycosyltransferase-ugt73a16-mutagenesis