02107nas a2200241 4500008004100000022001400041245014100055210006900196260008600265300001200351490000700363520118300370653001601553653002401569653001901593653001401612100001801626700001901644700002501663700002001688700002501708856013201733 2007 eng d a1521-654300aBile salt hydrolase, the member of Ntn-hydrolase family: differential modes of structural and functional transitions during denaturation0 aBile salt hydrolase the member of Ntnhydrolase family differenti a325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USAbTAYLOR & FRANCIS INCcFEB a118-1250 v593 a

Conformational transitions and functional stability of the bile salt hydrolase (BSH; cholylglycine EC: 3.5.1.24) from Bifidobacterium longum (BlBSH) cloned and expressed in E. coli were studied under thermal, chemical and pH-mediated denaturation conditions using fluorescence and CD spectroscopy. Thermal and Gdn-HCl-mediated denaturation of BlBSH is a multistep process of inactivation and unfolding. The inactivation and unfolding of the enzyme was found to be irreversible. Enzyme activity seems sensitive to even minor conformational changes at the active site. Thermal denaturation as such did not result in any insoluble protein aggregates. However, on treating with 0.25-1 M Gdn-HCl the enzyme showed increasing aggregation at temperatures of 40-55 degrees C indicating more complex structural changes taking place in the presence of chemical denaturants. The enzyme secondary structure was still intact at acidic pH (pH 1-3). The perturbation in the tertiary structure at the acidic pH was detected through freshly formed solvent exposed hydrophobic patches on the enzyme. These changes could be due to the formation of an acid-induced molten globule-like state.

10aAggregation10aBile salt hydrolase10amolten-globule10aUnfolding1 aKumar, Suresh1 aSuresh, C., G.1 aBrannigan, James, A.1 aDodson, Guy, G.1 aGaikwad, Sushama, M. uhttps://library.ncl.res.in/content/bile-salt-hydrolase-member-ntn-hydrolase-family-differential-modes-structural-and-functional01944nas a2200253 4500008004100000022001400041245010200055210006900157260007500226300001200301490000700313520104400320653001601364653002201380653001601402653002301418653001701441653001101458653001601469653002501485100002401510700002501534856013101559 2010 eng d a1053-050900aConformational and functional transitions in class II alpha-mannosidase from aspergillus fischeri0 aConformational and functional transitions in class II alphamanno a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGER/PLENUM PUBLISHERScJUL a827-8360 v203 a

The conformational transitions in an oligomeric and high molecular weight class II alpha-mannosidase from Aspergillus fischeri were examined using fluorescence and CD spectroscopy under chemical, thermal and acid denaturing conditions. The enzyme lost the activity first and then the overall folded conformation and secondary structure. The midpoint values of GdnHCl mediated changes measured by inactivation; fluorescence and negative ellipticity were 0.48 M, 1.5 M and 1.9 M, respectively. The protein almost completely unfolded in 4.0 M GdnHCl but not at 90 A degrees C. The inactivation and unfolding were irreversible. At pH 2.0, the protein exhibited molten-globule like intermediate with rearranged secondary and tertiary structures and exposed hydrophobic amino acids on the surface. This species showed increased accessibility of Trp to the quenchers and got denatured with GdnHCl in a different manner. The insoluble aggregates of a thermally denatured protein could be detected only in the presence of 0.25-0.75 M GdnHCl.

10aAggregation10aalpha-Mannosidase10aANS binding10aCircular dichroism10afluorescence10aGdnHCl10aHydrobicity10aThermal denaturation1 aShashidhara, K., S.1 aGaikwad, Sushama, M. uhttps://library.ncl.res.in/content/conformational-and-functional-transitions-class-ii-alpha-mannosidase-aspergillus-fischeri-001792nas a2200265 4500008004100000022001400041245008800055210006900143260007300212300001200285490000700297520083600304653001601140653003501156653001701191653001901208653004801227653001401275100002801289700002901317700002301346700002201369700002501391856011001416 2013 eng d a0141-813000aSolution and in silico studies on the recombinant lectin from Cicer arietinum seeds0 aSolution and in silico studies on the recombinant lectin from Ci aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a149-1550 v563 a

The Cicer arietinum seed lectin was cloned and expressed in Escherichia coli and purified in active form. Conformational characterization of the recombinant lectin (rCAL) was performed using biophysical and bioinformatics tools. Thermal denaturation of rCAL caused rapid secondary structural rearrangements above 50 degrees C and transient exposure of hydrophobic residues at 55 degrees C, leading to aggregation. Treatment of rCAL with GdnHCl resulted in unfolding followed by dissociation of the dimer. The single tryptophan in rCAL present on the surface of the protein is surrounded by hydrophobic and acidic amino acids and exists as different conformers. The experimental observations correlated well with the structural information revealed from the homology model of rCAL. (C) 2013 Elsevier B.V. All rights reserved.

10aAggregation10aBL21-CodonPlus (DE3)-RIL cells10aCicer lectin10aHomology model10aSteady-state and time resolved fluorescence10aUnfolding1 aWakankar, Madhurima, S.1 aKrishnasastry, Musti, V.1 aJaokar, Tulika, M.1 aPatel, Krunal, A.1 aGaikwad, Sushama, M. uhttps://library.ncl.res.in/content/solution-and-silico-studies-recombinant-lectin-cicer-arietinum-seeds-002418nas a2200253 4500008004100000022001400041245010700055210006900162260007300231300001200304490000700316520147800323653001601801653002001817653002701837653004101864653001401905100002101919700001801940700002701958700002701985700002502012856012702037 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

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.

10aAggregation10aCD spectroscopy10aFluorescence quenching10aMevalonate diphosphate decarboxylase10aUnfolding1 aShakeel, Abbassi1 aPatel, Krunal1 aKhan, Bashir, Mohammad1 aBhosale, Siddharth, H.1 aGaikwad, Sushama, M. uhttps://library.ncl.res.in/content/functional-and-conformational-transitions-mevalonate-diphosphate-decarboxylase-bacopa-0