02656nas a2200253 4500008004100000022001400041245014200055210006900197260009900266300001400365490000700379520163400386653002402020653004402044653001702088653002402105653002402129100001702153700002602170700002002196700003002216700002602246856013002272 2006 eng d a1359-511300aPurification, characterization and substrate specificity of thermostable alpha-galactosidase from Bacillus stearothermophilus (NCIM-5146)0 aPurification characterization and substrate specificity of therm aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcJUN a1311-13170 v413 a

An extracellular thermostable alpha-galactosidase from Bacillus stearothermophilus (NCIM-5146) has been purified to homogeneity by chromatographic step, using Phenyl Sepharose CL-4B column. The specific activity of the enzyme was increased approximately 389-fold, from 1.03 U/mg protein to 400 U/mg protein. The molecular mass of the purified enzyme as determined by SDS-PAGE and gel filtration was 79.9 and 165.9 kDa, respectively, suggesting dimeric nature. The purified alpha-galactosidase is a non-glycosylated protein with a pI of 4.9. The pH and temperature optima for the purified enzyme are 6.5-7.0 and 65 degrees C, respectively. The alpha-galactosidase is stable over a broad pH range (3-9) and its half-life of inactivation (t(1/2)) at 70 degrees C is 30 min. The partial N-terminal sequence of alpha-galactosidase showed remarkable homology (80% similarity) with earlier reported alpha-galactosidase from B. stearothermophilus NUB 3621. The secondary structure of the enzyme determined by circular dichroism (CD) spectroscopy exhibited alpha/beta class of protein and showed temperature induced conformational forms below and above the transition temperature. The purified enzyme showed biphasic Arrhenius plot with break point at 55 degrees C for pNPG and 50 degrees C for melibiose, raffinose and stachyose. The enzyme hydrolyzes alpha-1-3, alpha-1-4, and alpha-1-6 galactosidic linkages and not the beta-galactosidic linkages. Synthetic substrates pNPG and oNPG had lower K-m and higher K-cat as compare to natural substrates, melibiose, raffinose, and stachyose. (c) 2006 Elsevier Ltd. All rights reserved.

10aalpha-galactosidase10aBacillus stearothermophilus (NCIM-5146)10aPurification10aSecondary structure10athermostable enzyme1 aGote, M., M.1 aKhan, Mohammad, Islam1 aGokhale, D., V.1 aBastawade, Kulbhushan, B.1 aKhire, Jayant, Malhar uhttps://library.ncl.res.in/content/purification-characterization-and-substrate-specificity-thermostable-alpha-galactosidase-001652nas a2200217 4500008004100000022001400041245008300055210006900138260007300207300001200280490000700292520085400299653002301153653003501176653002401211100001901235700001901254700002601273700002501299856011001324 2008 eng d a0141-813000aStructure-activity relationship of a hemagglutinin from Moringa oleifera seeds0 aStructureactivity relationship of a hemagglutinin from Moringa o aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR a203-2070 v423 a

The hemagglutinin from the seeds of Moringa oleifera (MoL) agglutinates human as well as rabbit erythrocytes; the affinity for the latter is almost 250 times more than that for the former. MoL was inhibited by glycoproteins namely thyroglobulin, fetuin and holotransferin indicating the complex sugar specificity of the lectin. The protein is a homodimer with molecular mass of 14 kDa, subunits (7.1 kDa) linked by the disulfide bond(s). The secondary structure elements of MoL area-helix, 28%; beta-sheet, 23%; turn 20% and unordered 28%. While the activity and secondary structure were not affected at extreme pH and high temperature, they were drastically affected in presence of dithiothreitol at and above pH 7.0, indicating that disulfide linkages hold the active conformation of the protein. (C) 2007 Elsevier B.V. All rights reserved.

10adisulfide linkages10aMoringa oleifera hemagglutinin10aSecondary structure1 aKatre, Uma, V.1 aSuresh, C., G.1 aKhan, Mohammad, Islam1 aGaikwad, Sushama, M. uhttps://library.ncl.res.in/content/structure-activity-relationship-hemagglutinin-moringa-oleifera-seeds-002108nas a2200277 4500008004100000022001400041245011500055210006900170260007500239300001200314490000700326520110400333653002001437653001701457653001701474653002601491653002401517100002401541700002501565700001901590700001801609700002601627700002001653700002701673856013001700 2009 eng d a1053-050900aComparative studies of two araceous lectins by steady state and time-resolved fluorescence and CD spectroscopy0 aComparative studies of two araceous lectins by steady state and  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGER/PLENUM PUBLISHERScMAR a239-2480 v193 a

Transitions in the tryptophan microenvironment and secondary structure of two monocot lectins from Sauromatum guttatum and Arisaema tortuosum under different denaturing conditions were studied by steady state and time resolved fluorescence and CD spectroscopy. The lectins exist as tetramers with a single tryptophan residue estimated per monomer, present in a polar environment. Quenching with ionic quenchers showed predominantly electropositive environment for tryptophan residues. Acrylamide had maximum quenching effect. A decrease in KI quenching due to lectin denaturation indicated redistribution of charges as a result of possible conformational change. The two values for lifetimes of tryptophanyl population (1.2-1.4 and 6.3-6.4 ns) reduced substantially on quenching or denaturation. Similarly, both the lectins showed a drastic loss of secondary structure in 5 M Gdn-HCl or 6 M Urea or at pH 2.0 and below. For the first time araceous lectins, like legume lectins are shown to bind adenine. The presence of a compact structure at alkaline pH 10.0-12.0 was observed in CD spectra.

10aAraceae lectins10aDenaturation10afluorescence10aLifetime spectroscopy10aSecondary structure1 aDharker, Poorva, N.1 aGaikwad, Sushama, M.1 aSuresh, C., G.1 aDhuna, Vikram1 aKhan, Mohammad, Islam1 aSingh, Jatinder1 aKamboj, Sukhdev, Singh uhttps://library.ncl.res.in/content/comparative-studies-two-araceous-lectins-steady-state-and-time-resolved-fluorescence-and-002160nas a2200289 4500008004100000022001400041245011900055210006900174260007500243300001200318490000700330520114000337653001201477653002601489653001801515653001901533653002401552653002001576653001401596100002001610700002501630700001901655700001801674700002001692700002701712856013101739 2011 eng d a1053-050900aConformational transitions in ariesaema curvatum lectin: characterization of an acid induced active molten globule0 aConformational transitions in ariesaema curvatum lectin characte a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGER/PLENUM PUBLISHERScMAR a753-7630 v213 a

Biophysical characterization of a lectin from Ariesaema curvatum (ACL) was carried out using steady state as well as time resolved fluorescence and CD spectroscopy under various denaturing conditions. An intermediate with altered tryptophan microenvironment was detected in the phase diagram, which exibited pronounced secondary structure and hemagglutinating activity in presence of 0.25 M Gdn-HCl. An acid induced molten- globule like structure possessing activity and higher thermostability was detected. Transition to the molten globule state was reversible in nature. The lectin retained hemagglutinating activity even after incubation at 95 A degrees C. Both chemical and thermal unfolding of the lectin were found to consist of multistate processes. Fluorescence quenching of ACL was strong with acrylamide and KI. The single tryptophan was found to be surrounded by high density of the positively charged amino acid residues as shown by a ten fold higher K(sv) for KI compared to that for CsCl. The average lifetime of tryptophan fluorescence increased from 1.24 ns in the native state to 1.72 ns in the denatured state.

10aAraceae10aFluorescence lifetime10aHemagglutinin10aMolten globule10aSecondary structure10aThermostability10aUnfolding1 aSharma, Urvashi1 aGaikwad, Sushama, M.1 aSuresh, C., G.1 aDhuna, Vikram1 aSingh, Jatinder1 aKamboj, Sukhdev, Singh uhttps://library.ncl.res.in/content/conformational-transitions-ariesaema-curvatum-lectin-characterization-acid-induced-active-002644nas a2200277 4500008004100000022001400041245011100055210006900166260000800235300000800243490000600251520174300257653002102000653002302021653001102044653002402055653001402079100001702093700001802110700002202128700002002150700002102170700002402191700002502215856012602240 2018 eng d a2190-572X00aCloning and characterization of trehalase: a conserved glycosidase from oriental midge, Chironomus ramosus0 aCloning and characterization of trehalase a conserved glycosidas cAUG a3520 v83 a

Insect trehalase is a multiferous enzyme, crucial for normal physiological functions as well as under stress conditions. In this report, we present a fundamental study of the trehalase gene segment (1587 bp) from Chironomus ramosus (CrTre) encoding for 529 amino acids, using appropriate bioinformatics tools. C. ramosus, a tropical midge is an emerging animal model to investigate the consequences of environmental stresses. We observed that CrTre belongs to GH family 37 in the CAZy database and possess 57-92% identity to dipteran trehalases. In silico characterization provided information regarding the structural, functional and evolutionary aspects of midge trehalase. In the phylogenetic tree, CrTre clustered with the soluble dipteran trehalases. Moreover, domain functional characterization of the deduced protein sequence by InterProScan (IPR001661), ProSite (PS00927 and PS00928) and Pfam (PF01204) indicated presence of highly conserved signature motifs which are important for the identification of trehalase superfamily. Furthermore, the instability index of CrTre was predicted to be < 40 suggesting its in vivo stability while, the high aliphatic index indicated towards its thermal stability (index value 71-81). The modelled 3D tertiary structure of CrTre depicts a (alpha/alpha)(6) barrel toroidal core. The catalytic domain of the enzyme comprised Glu424 and Asp226 as the putative active site residues. Interestingly, the conserved motifs were observed to be formed by the flexible loopy regions in the tertiary structure. This study revealed essential sequence features of the midge trehalase and offers better insights into the structural aspects of this enzyme which can be correlated with its function.

10aConserved motifs10aHomology modelling10aMidges10aSecondary structure10atrehalose1 aShukla, Ekta1 aThorat, Leena1 aBendre, Ameya, D.1 aJadhav, Santosh1 aPal, Jayanta, K.1 aNath, Bimalendu, B.1 aGaikwad, Sushama, M. uhttps://library.ncl.res.in/content/cloning-and-characterization-trehalase-conserved-glycosidase-oriental-midge-chironomus01814nas a2200217 4500008004100000022001400041245018100055210006900236260000800305300001000313490000700323520097900330653003501309653001801344653000901362653000901371653003601380653002401416100002601440856013001466 2019 eng d a1742-758400aSecondary structure of the internal transcribed rDNA (ITS) regions of cosmopolites sordidus (Germar) and odoiporus longicollis (Olivier): a first report in family Curculionidae0 aSecondary structure of the internal transcribed rDNA ITS regions cMAR a53-610 v393 a

In the present work the consensus secondary structure of the internal transcribed rDNA spacers ITS1 and ITS2 of two weevils i.e. Cosmopolites sordidus (Germar) and Odoiporus longicollis (Olivier) has been described. The secondary structures of the ITS1 region of C.sordidus and O.longicollis have ten and five helices respectively, emerging from a central core. Two and five helices emerge from a central core in the ITS2 secondary structures of C.sordidus and O.longicollis respectively, and do not conform to the `paneukaryotic' four domain model. The ITS2 sequences of these two weevils share three regions with maximum sequence identity. Of these, two are present at the 5' and 3' end and share structural similarity, suggesting their possible role in the processing of the rRNA. This is the first report of the secondary structure of the ITS region in family Curculionidae which can serve as a valuable resource for homology modelling and phylogenetic studies.

10aCosmopolites sordidus (Germar)10aCurculionidae10aITS110aITS210aOdoiporus longicollis (Olivier)10aSecondary structure1 aKumar, Lalitha, Sunil uhttps://library.ncl.res.in/content/secondary-structure-internal-transcribed-rdna-its-regions-cosmopolites-sordidus-germar-and