Thirunavukkarasu Sivaraman

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Ribavirin and its 553 analogues have been docked with NS5-methyltransferase of Dengue viruses using Glide-HTVS and Glide-XP computational tools and the compounds have been screened based on their Glide-Gscores to identify lead ribavirin analogues that may act as inhibitors to the enzyme. Upon studying the interactions of ribavirin triphosphate (RTP) and(More)
Amide hydrogen (NH) exchange is one of the few experimental techniques with the potential for determining the thermodynamics and kinetics of conformational motions at nearly every residue in native proteins. Quantitative interpretation of NH exchange in terms of molecular motions relies on a simple two-state kinetic model: at any given slowly exchanging NH,(More)
Despite their structural similarities, the natural products chelerythrine ( 5) and sanguinarine ( 6) target different binding sites on the pro-survival Bcl-X L protein. This paper details the synthesis of phenanthridine-based analogues of the natural products that were used to probe this difference in binding profiles. The inhibitory constants for these(More)
Understanding the relationships between conformations of proteins and their stabilities is one key to address the protein folding paradigm. The free energy change (ΔG) of unfolding reactions of proteins is measured by traditional denaturation methods and native hydrogen-deuterium (H/D) exchange methods. However, the free energy of unfolding (ΔG(U)) and the(More)
The crucial residues of hBaxBH3 peptide for interaction with hBcl-B, an anti-apoptotic protein, were identified using molecular docking studies on the polypeptides and temperature-specific molecular dynamic simulations performed for the protein-peptide complex at near-physiological conditions (pH 7.0, 1 atmospheric pressure and 0.1 M NaCl). The data from(More)
Structurally similar but functionally different two paralogous proteins, CTX1 (a cardiotoxin) and LNTX2 (an alpha-neurotoxin), from venom of Naja naja naja have been homology modeled and subjected to molecular dynamics (MD) simulations at four different temperatures (298 K, 310 K, 373 K & 473 K) under close quarters of physiological conditions. Each MD(More)
The screening of a small focused library of rhodanine derivatives as inhibitors of Bcl-2 proteins led to the discovery of two structurally related compounds with different binding profiles against the Bcl-XL and the Mcl-1 proteins. Subsequent NMR studies with mutant proteins and in silico docking studies provide a possible rationale for the observed(More)
The refolding kinetics of Cobrotoxin (CBTX), a small all beta-sheet protein is investigated using a variety of biophysical techniques including quenched-flow hydrogen-deuterium (H/D) exchange in conjunction with two-dimensional NMR spectroscopy. Urea-induced equilibrium unfolding of CBTX follows a two-state mechanism with no distinct intermediates. The(More)
The thermodynamic stabilities (∆G, free energy change) of proteins are being measured by traditional denaturation methods (∆GU, free energy of unfolding) and native hydrogen-deuterium (H/D) exchange method (∆GHX, free energy of exchange), in general. Estimation of an accurate ∆G for proteins at ambient conditions is indispensable to unambiguously address(More)
The unfolding kinetics of cardiotoxin analogue VI from Taiwan cobra (Naja naja atra) have been studied at 473 K, pH 7.0 in the presence of 0.1 M NaCl using molecular dynamics simulations for 50 ns. Trajectory structures stored at every 25 ps (2000 structures) were probed at molecular (RMSD and radius of gyration) and residue (RMSF, surface area(More)