01956nas a2200229 4500008004100000022001400041245015200055210006900207260008900276300001200365490000700377520103600384653003001420653002201450653001101472653002401483653002901507100002301536700001801559700002601577856012301603 2008 eng d a1050-464800aPurification and characterization of a T-antigen specific lectin from the coelomic fluid of a marine invertebrate, sea cucumber (Holothuria scabra)0 aPurification and characterization of a Tantigen specific lectin  a24-28 OVAL RD, LONDON NW1 7DX, ENGLANDbACADEMIC PRESS LTD ELSEVIER SCIENCE LTDcAPR a450-4580 v243 a

A novel lectin was purified from the coelomic fluid of the sea cucumber Holothuria scabra (HSL), subjected to bacterial challenge. HSL is a monomeric glycoprotein of molecular mass 182 kDa. The lectin is highly thermostable as it retains full activity for 1 h at 80 degrees C. Further, the hemagglutination activity of HSL is unaffected by pH in the range 2-11. Unlike other lectins purified from marine invertebrates, the hemagglutination activity of HSL does not require any divalent metal ions. The affinity profile of HSL was studied by a combination of hemagglutination inhibition and fluorescence spectroscopy. HSL binds to desialylated glycoproteins, Me alpha Gal, T-antigen and T (alpha-ser)-antigen with a distinction between beta 1-4 and beta 1-3 linkages. Me alpha-T-antigen was a potent ligand having highest affinity (K-a 8.32 x 10(7) M-1). Monosaccharide binding is enthalphically driven while disaccharide binding involves both entropic and enthalpic contributions. (c) 2008 Elsevier Ltd. All rights reserved.

10aFluorescence spectroscopy10aHolothuria scabra10aLectin10amarine invertebrate10aThermodynamic properties1 aGowda, Nagaraj, M.1 aGoswami, Usha1 aKhan, Mohammad, Islam uhttps://library.ncl.res.in/content/purification-and-characterization-t-antigen-specific-lectin-coelomic-fluid-marine-001799nas a2200229 4500008004100000022001400041245008700055210006900142260011000211300001400321490000700335520090100342653003301243653002401276653003001300653001801330653002901348100002301377700002401400700002901424856011601453 2013 eng d a0376-471000aSynthesis and fluorescence properties of a full set of extended RNA base analogues0 aSynthesis and fluorescence properties of a full set of extended  aDR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIAbNATL INST SCIENCE COMMUNICATION-NISCAIRcAUG a1004-10130 v523 a

The synthesis and photophysical characterization of a complete set of fluorescent RNA base analogues derived by conjugating benzofuran moiety at the 5- and 8-positions of pyrimidine and purine bases, respectively, are described. Benzofuran-modified pyrimidine and purine ribonucleoside analogues exhibit Contrasting fluorescence properties. Pyrimidine analogues are moderately emissive with emission maximum in the visible region, and importantly, are highly sensitive to solvent polarity and Viscosity changes. On the other hand, purine analogues are highly emissive and are minimally affected by solvation. and viscosity effects. Thorough photophysical analysis reveals that the pyrimidine and purine ribonucleosides displaying distinct and-probe-like fluorescence properties could be useful in designing nucleic acid based biophysical tools to study nucleic acid structure and function.

10aEnvironment sensitive probes10aFluorescence probes10aFluorescence spectroscopy10aNucleic acids10aRibonucleoside analogues1 aSabale, Pramod, M.1 aNuthanakanti, Ashok1 aSrivatsan, Seergazhi, G. uhttps://library.ncl.res.in/content/synthesis-and-fluorescence-properties-full-set-extended-rna-base-analogues-002266nas a2200217 4500008004100000022001400041245010100055210006900156260000800225300001100233490000800244520150100252653003101753653003001784653002801814653002201842100001901864700001701883700002401900856012401924 2021 eng d a0301-462200apH-dependent protein stability switch coupled to the perturbed pKa of a single ionizable residue0 apHdependent protein stability switch coupled to the perturbed pK cJUL a1065910 v2743 a

The contribution of electrostatic interactions in protein stability has not been fully understood. Burial of an ionizable amino acid inside the hydrophobic protein core can affect its ionization equilibrium and shift its pKa differentially in the native (N) and unfolded (U) states of a protein and this coupling between the folding/ unfolding cycle and the ionization equilibria of the ionizable residue can substantially influence the protein stability. Here, we studied the coupling of the folding/unfolding cycle with the ionization of a buried ionizable residue in a multi-domain protein, Human Serum Albumin (HSA) using fluorescence spectroscopy. A pHdependent change in the stability of HSA was observed in the near native pH range (pH 6.0-9.0). The protonation-deprotonation equilibrium of a single thiol residue that is buried in the protein structure was identified to give rise to the pH-dependent protein stability. We quantified the pKa of the thiol residue in the N and the U states. The mean pKa of the thiol in the N state was upshifted by 0.5 units to 8.7 due to the burial of the thiol in the protein structure. Surprisingly, the mean pKa of the thiol in the U state was observed to be downshifted by 1.3 units to 6.9. These results indicate that some charged residues are spatially proximal to the thiol group in the U state. Our results suggest that, in addition to the N state, electrostatic interactions in the U state are important determinants of protein stability.

10aelectrostatic interactions10aFluorescence spectroscopy10aThermodynamic stability10aUnfolded proteins1 aMishra, Prajna1 aPatni, Divya1 aJha, Santosh, Kumar uhttps://library.ncl.res.in/content/ph-dependent-protein-stability-switch-coupled-perturbed-pka-single-ionizable-residue