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-0