Thermodynamics Research Today is a free monthly online journal that collates and summarizes the latest research about Thermodynamics, including details on enthalpy, entropy, energy transitions. | ||||||
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Synthesis and thermodynamic characterization of small cyclic antimicrobial arginine and tryptophan-rich peptides with selectivity for gram-negative bacteria.Bagheri M Leibniz Institute of Molecular Pharmacology (FMP), Berlin, Germany. One promising strategy to combat the proliferation of bacteria resistance toward current antibiotics is the development of peptide-based drug. Among these compounds is a group of small cyclic peptides rich in arginine (Arg) and tryptophan (Trp) residues with selective toxicity toward Gram-negative bacteria. The small size of these peptides with improved toxicity toward Gram-negative bacteria makes them an interesting candidate to understand the forces responsible for their selectivity and paves the way to develop new therapeutics with potent activity toward multi-resistant Gram-negative bacteria. To reach this goal, isothermal titration calorimetry (ITC) is a useful technique which may provide the complete set of thermodynamic parameters of the interaction of peptides with lipid bilayers mimicking the properties of bacterial membranes within a few hours. The purpose of this chapter is to describe the synthesis of this group of small synthetic antimicrobial peptides together with the application of ITC to study their interaction with lipid membranes. Published 22 January 2010 in Methods Mol Biol, 618: 87-109. Articles on Thermodynamics published 22 January 2010: Measurement of universal thermodynamic functions for a unitary Fermi gas. Science, 327(5964): 442-5. Thermodynamic properties of matter generally depend on the details of interactions between its constituent parts. However, in a unitary Fermi gas where the scattering length diverges, thermodynamics is determined through universal functions that depend only on the particle density and temperature. By using only the general form of the equation of state and the equation of force balance, we measured the local internal energy of the trapped gas as a function of these parameters. Other universal ... [Abstract] [Full-text] Articles on Thermodynamics published 21 January 2010: On Some Aspects of the Thermodynamic of Membrane Recycling Mediated by Fluid Phase Endocytosis: Evaluation of Published Data and Perspectives. Cell Biochem Biophys. The theoretical and experimental description of fluid phase endocytosis (FPE) requires an asymmetry in phospholipid number between the two leaflets of the cell membrane, which provides the biomechanical torque needed to generate membrane budding. Although the motor force behind FPE is defined, its kinetic has yet to be determined. Based on a body of evidences suggesting that the mean surface tension is unlikely to be involved in endocytosis we decided to determine whether the cytosolic ... [Abstract] [Full-text] Varenicline L-tartrate crystal forms: Characterization through crystallography, spectroscopy, and thermodynamics. J Pharm Sci. This research utilized crystallographic, spectroscopic, and thermal analysis data to assess the thermodynamic stability relationship between the three known crystal forms of Varenicline L-tartrate. Of the two anhydrous forms (Forms A and B), Form B was determined to be the stable form at 0 K based on its calculated true density, hydrogen bonding in the crystal lattice, and application of the IR rule. Form A has a higher melting point and higher solubility at room temperature as compared to Form ... [Abstract] [Full-text] Crystal polymorphism of the anti-diabetic drug Tolbutamide (TB) has been studied using various analytical techniques. TB crystallizes in four polymorphic forms (Forms I-IV), which differ in their mode of packing and in molecular conformation but with similar hydrogen bonding synthon (urea tape motif). All the structures were solved from single crystal X-ray data, except for Form IV, which was solved using conventional powder X-ray diffraction (PXRD) data. The conformational differences in the ... [Abstract] [Full-text] Prediction of the binding affinities of peptides to class II MHC using a regularized thermodynamic model. BMC Bioinformatics, 11(1): 41. ABSTRACT: BACKGROUND: The binding of peptide fragments of extracellular peptides to class II MHC is a crucial event in the adaptive immune response. Each MHC allotype generally binds a distinct subset of peptides and the enormous number of possible peptide epitopes prevents their complete experimental characterization. Computational methods can utilize the limited experimental data to predict the binding affinities of peptides to class II MHC. RESULTS: We have developed the Regularized ... [Abstract] [Full-text] Thermodynamic and structural behaviour of equimolar POPC/C(n)E(4) (n=8, 12, 16) mixtures by sorption gravimetry, (2)H NMR spectroscopy and X-ray diffraction. Chem Phys Lipids. The hydration behaviour of equimolar mixtures of phospholipids and nonionic surfactants with different chain length was investigated by gravimetric sorption, NMR spectroscopy and X-ray diffraction. At the most hydration degrees investigated, the incorporation of nonionic surfactants in a phospholipid bilayer leads to an increase of the hydrophilicity, which can be shown by the presence of excess hydration. The increased hydrophilicity could be explained by the excavation of additional water ... [Abstract] [Full-text] Thermodynamics of binding of regulatory ligands to tissue transglutaminase. Amino Acids. The transamidating activity of tissue transglutaminase is regulated by the ligands calcium and GTP, via conformational changes which facilitate or interfere with interaction with the peptidyl-glutamine substrate. We have analysed binding of these ligands by calorimetric and computational approaches. In the case of GTP we have detected a single high affinity site (K (D) approximately 1 muM), with moderate thermal effects suggestive that binding GTP involves replacement of GDP, normally bound to ... [Abstract] [Full-text] Articles on Thermodynamics published 20 January 2010: Hybridization thermodynamics of NimbleGen Microarrays. BMC Bioinformatics, 11(1): 35. ABSTRACT: BACKGROUND: While microarrays are the predominant method for gene expression profiling, probe signal variation is still an area of active research. Probe signal is sequence dependent and affected by probe-target binding strength and the competing formation of probe-probe dimers and secondary structures in probes and targets. RESULTS: We demonstrate the benefits of an improved model for microarray hybridization and assess the relative contributions of the probe-target binding strength ... [Abstract] [Full-text] © 2005-2010 Thermodynamics Research Today. All Rights Reserved. |
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