02706nas a2200277 4500008004100000022001400041245015800055210006900213260005700282300001200339490000700351520166600358653003502024653002002059653002302079653002502102100002702127700000902154700001802163700002702181700002302208700001602231700002602247700002702273856012802300 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

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.

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 uhttp://library.ncl.res.in/content/molecular-cloning-biochemical-characterization-and-differential-expression-acetyl-coa-c-002145nas a2200241 4500008004100000022001400041245008700055210006900142260007300211300001200284490000700296520129500303653002001598653002001618653002201638653001401660100001601674700002701690700002301717700002101740700002701761856011501788 2015 eng d a0141-813000aBiochemical characterization of recombinant mevalonate kinase from Bacopa monniera0 aBiochemical characterization of recombinant mevalonate kinase fr aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a776-7830 v723 a

Mevalonate kinase (MK; ATP: mevalonate 5-phosphotransferase; EC 2.7.1.36) plays a key role in isoprenoid biosynthetic pathway in plants. MK catalyzes the phosphorylation of mevalonate to form mevalonate-5-phosphate. The recombinant BmMK was cloned and over-expressed in E. coli BL21 (DE3), and purified to homogeneity by affinity chromatography followed by gel filtration. Optimum pH and temperature for forward reaction was found to be 7.0 and 30 degrees C, respectively. The enzyme was most stable at pH 8 at 25 degrees C with deactivation rate constant (Kd*) 1.398 x 10(-4) and half life (t(1/2)) 49 h. pH activity profile of BmMK indicates the involvement of carboxylate ion, histidine, lysine, arginine or aspartic acid at the active site of enzyme. Activity of recombinant BmMK was confirmed by phosphorylation of RS-mevalonate in the presence of Mg2+, having K-m and V-max 331.9 mu M and 719.1 pKat mu g(-1), respectively. The values of k(cat) and k(cat)/K-m for RS-mevalonate were determined to be 143.82 s(-1) and 0.43332 M-1 s(-1) and k(cat) and k(cat)/K-m values for ATP were found 150.9 s(-1) and 1.023 M-1 s(-1). The metal ion studies suggested that BmMK is a metal dependent enzyme and highly active in the presence of MgCl2. (C) 2014 Elsevier B.V. All rights reserved.

10aBacopa monniera10aEnzyme kinetics10aMevalonate kinase10astability1 aKumari, Uma1 aVishwakarma, Rishi, K.1 aSonawane, Prashant1 aAbbassi, Shakeel1 aKhan, Bashir, Mohammad uhttp://library.ncl.res.in/content/biochemical-characterization-recombinant-mevalonate-kinase-bacopa-monniera-002467nas a2200325 4500008004100000022001400041245016100055210006900216260005700285300001400342490000700356520130200363653001901665653002001684653003701704653002801741653002301769653002201792100002701814700001801841700002301859700001601882700001801898700000901916700002101925700002401946700002101970700002701991856012302018 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

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.

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 uhttp://library.ncl.res.in/content/c-squalene-synthase-gene-medicinal-herb-bacopa-monniera-molecular-characterization-0