02449nas a2200265   4500008004100000022001400041245010100055210006900156260000800225300001000233490000700243520157500250653001701825653001201842653001901854653001901873653003301892653002401925100001701949700002001966700002601986700002002012700002102032856013002053       2016                        eng d  a0141-813000aStructural-functional insights and studies on saccharide binding of Sophora japonica seed lectin0 aStructuralfunctional insights and studies on saccharide binding   cOCT  a75-840 v913 a<p>Functional and conformational transitions of the Sophora japonica seed lectin (SJL) were studied in detail using bioinformatics and biophysical tools. Homology model of the lectin displayed all the characteristics of the legume lectin monomer and the experimental observations correlated well with the structural information. In silico studies were performed by protein-ligand docking, calculating the respective binding energies and the residues involved in the interactions were derived from LigPlot(+) analysis. Fluorescence titrations showed three times higher affinity of T-antigen disaccharide than N-acetyl galactosamine (GaINAc) towards SJL indicating extended sugar binding site of the lectin. Thermodynamic parameters of T-antigen binding to SJL indicated the process to be endothermic and entropically driven while those of GaINAc showed biphasic process. SDS-PAGE showed post-translationally modified homotetrameric species of the lectin under native conditions. In presence of guanidine hydrochloride (0.5-5.0 M), the tetramer first dissociated into dimers followed by unfolding of the protein as indicated by size exclusion chromatography, fluorescence and CD spectroscopy. Different structural rearrangements were observed during thermal denaturation of SJL at physiological pH 7.2, native pH 8.5 and molten globule inducing pH 1.0. Topological information revealed by solute quenching studies at respective pH indicated differential hydrophobic environment and charge density around tryptophan residues. (C) 2016 Elsevier B.V. All rights reserved.</p>10aDissociation10adocking10aHomology model10aLigand binding10aSophora japonica seed lectin10aThermal transitions1 aYadav, Priya1 aShahane, Ganesh1 aRamasamy, Sureshkumar1 aSengupta, Durba1 aGaikwad, Sushama  uhttps://library.ncl.res.in/content/structural-functional-insights-and-studies-saccharide-binding-sophora-japonica-seed-lectin02021nas a2200145   4500008004100000245012200041210006900163260000800232490000600240520143500246100001701681700002001698700002501718856013201743       2017                        eng d00aAmaranthus caudatus lectin with polyproline II fold: conformational and functional transitions and molecular dynamics0 aAmaranthus caudatus lectin with polyproline II fold conformation  cJUL0 v13 aPolyproline II (PPII) fold, a peculiar structural element was detected in the Amaranthus caudatus seed lectin (ACL) based on far UV circular dichroism spectrum, conformational transitions of the lectin and a distinct isodichroic point in thermal denaturation. It was confirmed by using PolyprOnline database to estimate the percentage of amino acids contributing to PPII fold and showed the values as 13.5% and 13.9% for PROSS and XTLSSTR, respectively. Investigations of the functional and conformational transitions of ACL during thermal, pH and guanidine hydrochloride (GdnHCl) induced denaturation were carried out using biochemical and biophysical techniques and molecular dynamics (MD) simulations approach. The lectin got aggregated at 60 °C with instantaneous structural alterations. The aggregation-prone regions in ACL were predicted using online servers viz. AGGRESCAN, AmylPred, FoldAmyloid and Waltz that were represented by Visual Molecular Dynamics tools. Nine conserved regions were identified by these softwares as being ‘hot-spots’ for aggregation. MD simulation studies of the lectin at 60 °C revealed increase in radius of gyration. The loss of PPII fold in 2.0 M GdnHCl was reversible. The partially unfolded intermediate of ACL with diminished PPII fold formed at pH 1.0 was stable up to 90 °C. The polyproline II fold has been rarely detected in lectins, ACL being the second after the potato lectin.1 aYadav, Priya1 aShahane, Ganesh1 aGaikwad, Sushama, M.  uhttps://library.ncl.res.in/content/amaranthus-caudatus-lectin-polyproline-ii-fold-conformational-and-functional-transitions-and