02187nas a2200241   4500008004100000022001400041245009900055210006900154260007300223300001200296490000700308520130000315653004101615653002401656653002601680653001401706100002101720700002701741700001701768700001601785700002701801856011701828       2015                        eng d  a0141-813000aBacopa monniera recombinant mevalonate diphosphate decarboxylase: biochemical characterization0 aBacopa monniera recombinant mevalonate diphosphate decarboxylase  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG  a661-6680 v793 a<p>Mevalonate diphosphate decarboxylase (MDD; EC 4.1.1.33) is an important enzyme in the mevalonic acid pathway catalyzing the Mg2+-ATP dependant decarboxylation of mevalonate 5-diphosphate (MVAPP) to isopentenyl diphosphate (IPP). Bacopa monniera recombinant MDD (BmMDD) protein was overexpressed in Escherichia coli BL21 (DE3) strain and purified to apparent homogeneity. K-m and V-max for MVAPP were 144 mu M and 52 U mg(-1) respectively. The values of turnover (k(cat)) and k(cat)/K-m, for mevalonate 5-diphosphate were determined to be 40 s(-1) and 2.77 x 10(5) M-1 s(-1) and k(cat) and k(cat)/K-m values for ATP were found to be 30 s(-1) and 2.20 x 10(4) M-1 s(-1), respectively. pH activity profile indicated the involvement of carboxylate ion, lysine and arginine for the activity of enzyme. The apparent activation energy for the BmMDD catalyzed reaction was 12.7 kJ mol(-1). Optimum pH and temperature for the forward reaction was found to be 8.0 and 45 degrees C. The enzyme was most stable at pH 7 at 20 degrees C with the deactivation rate constant (K-d(*)) of 1.69 x 10(-4) and half life (t(1/2)) of 68 h. The cation studies suggested that BmMDD is a cation dependant enzyme and optimum activity was achieved in the presence of Mg2+. (C) 2015 Elsevier B.V. All rights reserved.</p>10aMevalonate diphosphate decarboxylase10apH activity profile10aPhylogenetic analysis10astability1 aAbbassi, Shakeel1 aVishwakarma, Rishi, K.1 aPatel, Parth1 aKumari, Uma1 aKhan, Bashir, Mohammad  uhttp://library.ncl.res.in/content/bacopa-monniera-recombinant-mevalonate-diphosphate-decarboxylase-biochemical-102417nas a2200253   4500008004100000022001400041245010700055210006900162260007300231300001200304490000700316520147800323653001601801653002001817653002701837653004101864653001401905100002101919700001801940700002701958700002701985700002502012856012602037       2016                        eng d  a0141-813000aFunctional and conformational transitions of mevalonate diphosphate decarboxylase from Bacopa monniera0 aFunctional and conformational transitions of mevalonate diphosph  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB  a160-1700 v833 a<p>Functional and conformational transitions of mevalonate diphosphate decarboxylase (MDD), a key enzyme of mevalonate pathway in isoprenoid biosynthesis, from Bacopa monniera (BmMDD), cloned and overexpressed in Escherichia coli were studied under thermal, chemical and pH-mediated denaturation conditions using fluorescence and Circular dichroism spectroscopy. Native BmMDD is a helix dominant structure with 45% helix and 11% sheets and possesses seven tryptophan residues with two residues exposed on surface, three residues partially exposed and two situated in the interior of the protein. Thermal denaturation of BmMDD causes rapid structural transitions at and above 40 degrees C and transient exposure of hydrophobic residues at 50 degrees C, leading to aggregation of the protein. An acid induced molten globule like structure was observed at pH 4, exhibiting altered but compact secondary structure, distorted tertiary structure and exposed hydrophobic residues. The molten globule displayed different response at higher temperature and similar response to chemical denaturation as compared to the native protein. The surface tryptophans have predominantly positively charged amino acids around them, as indicated by higher K-SV for IC as compared to that for CsCl. The native enzyme displayed two different lifetimes, vi (1.203 +/- 0.036 ns) and tau 2 (3.473 +/- 0.12 ns) indicating two populations of tryptophan. (C) 2015 Elsevier B.V. All rights reserved.</p>10aAggregation10aCD spectroscopy10aFluorescence quenching10aMevalonate diphosphate decarboxylase10aUnfolding1 aShakeel, Abbassi1 aPatel, Krunal1 aKhan, Bashir, Mohammad1 aBhosale, Siddharth, H.1 aGaikwad, Sushama, M.  uhttp://library.ncl.res.in/content/functional-and-conformational-transitions-mevalonate-diphosphate-decarboxylase-bacopa-0