7,165 research outputs found
Structure and dynamics of soluble proteins as a tool to understand their molecular mechanism of action: A combined use of NMR and molecular dynamic calculations
No full textFrom structural studies to the optimization of a vaccine: the case of the protein Sm14 from S. mansoni
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Target metabolomic analysis of Red Blood Cells transfusion bags: role of hypoxanthine in neutrophil activation.
No full textRed Blood Cells (RBCs) stored in blood bank conditions, undergo biological/biochemical changes collectively referred as "storage lesions". The RBCs bags metabolic profile was evaluated during storage (up to 42 days) by 1H-NMR spectroscopy [1]. More than 30 metabolites were identified: we observed a significant increase of hypoxanthine (HX) concentration in aged RBCs units [2]. This intermediate of purine pathway is a pro-oxidant molecule: its oxidation by xanthine oxidase (XO) produces reactive oxygen species (ROS, O2•- and H2O2) as by-products. ROS play a central role in inflammation, acting as direct mediators and/or being involved in neutrophil activation and downstream inflammatory response mediated by cytokines and chemokines. In vitro studies on neutrophil priming/activation, induced by RBCs storage medium, attributed this effect to the presence of bioactive substances, such as lipids [3]. The search of other mediators is still an open question. Since the role of HX was not previously investigated, our aim is to discern its role on neutrophil activation. The effect of 42 days old RBCs supernatants and HX (+/- XO in both conditions) on isolated neutrophils in culture was assessed by flow cytometry and ELISA assays.
An increase of the intracellular cytokine TNFα and a release of chemokine IL-8 in the extra-cellular space were observed. Both effects were absent in presence of allopurinol, XO inhibitor, thus demonstrating the role played by HX on neutrophil activation.
References
[1] Pertinhez, T.A., Berni, P., Casali, E., Lindner, L., Spisni, A., Baricchi, R. Blood Transfus. 12, 548 (2014)
[2] Casali, E., Berni, P., Spisni, A., Baricchi, R., Pertinhez, T.A. Blood Transfus. 14, 555 (2016)
[3] Silliman, C.C., Moore, E.E., Kelher, M.R., Khan, S.Y., Gellar, L., Elzi, D. J. Transf. 51, 2549 (2011
Ligands turning around in the midst of protein conformers: the origin of ligand-protein mating. A NMR view
No full textProtein-ligand binding is a puzzling process. Many theories have been devised since the pioneering key-and-lock hypothesis based on the idea that both the protein and the ligand have a rigid single conformation.
Indeed, molecular motion is the essence of the universe. Consequently, not only proteins are characterized by an extraordinary conformational freedom, but ligands too can fluctuate in a rather vast conformational space. In this scenario, the quest to understand how do they match is fascinating.
Recognizing that the inherent dynamics of molecules is the key factor controlling the success of binding and, subsequently, of their chemical/biological function, here we present a view of this process from the NMR stand point.
A description of the most relevant NMR parameters that can provide insights, at atomic level, on the mechanisms of protein- ligand binding is provided in the final section
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