It is found that, although vesicle size and polydispersity are not significantly altered by the formation of membrane domains, the area fraction occupied by domains depends

on the overall vesicle size. In particular, increasing membrane curvature (i.e., decreasing vesicle size) results in increased area fractions of membrane domains.”
“Vibrio cholerae secretes a large virulence-associated multifunctional autoprocessing RTX toxin ( MARTXVc). Autoprocessing NVP-BSK805 ic50 of this toxin by an embedded cysteine protease domain (CPD) is essential for this toxin to induce actin depolymerization in a broad range of cell types. A homologous CPD is also present in the large clostridial toxin TcdB and recent studies showed Nocodazole mechanism of action that inositol hexakisphosphate (Ins(1,2,3,4,5,6) P6 or InsP6) stimulated the autoprocessing of TcdB dependent upon the CPD ( Egerer, M., Giesemann, T., Jank, T., Satchell, K. J., and Aktories, K. (2007) J. Biol. Chem. 282, 25314-25321). In this work, the autoprocessing activity of the CPD within MARTXVc is similarly found to be inducible by InsP6. The CPD is shown to bind InsP6 ( Kd, 0.6 mu M), and InsP6 is shown to stimulate intramolecular autoprocessing at both physiological concentrations and as low as 0.01 mu M. Processed CPD did not bind InsP6 indicating that, subsequent to cleavage, the activated CPD may shift to an inactive conformation. To further pursue the mechanism of autoprocessing,

conserved residues among 24 identified CPDs were mutagenized. In addition to cysteine and histidine residues that form the catalytic site, 2 lysine residues VX-661 nmr essential for InsP6 binding and 5 lysine and arginine residues resulting in loss of activity at low InsP6 concentrations were identified. Overall, our data support a model in which basic residues located across the CPD structure form an InsP6 binding pocket and that the binding of InsP6 stimulates processing by altering the CPD to an activated conformation. After processing, InsP6 is shown to be

recycled, while the cleaved CPD becomes incapable of further binding of InsP6.”
“BACKGROUND: The aim of this study was to find natural spice and herb extracts with antibacterial and antioxidant capacities that could be potentially used as natural preservatives in raw pork.\n\nRESULTS: The inhibitory effects of cinnamon stick, oregano, clove, pomegranate peel and grape seed extracts on Listeria monocytogenes, Staphylococcus aureus and Salmonella enterica were evaluated in raw pork at room temperature (similar to 20 degrees C). The influences of these extracts on lipid oxidation in the meat were also investigated. The pH, colour parameters and TBARS (thiobarbituric acid-reactive substances) values were tested periodically. The results showed that all five natural extracts, especially clove, were effective against the bacteria. During storage the colour parameters of the extract-treated pork samples changed slightly, in comparison with significant changes in the control.