1ut3
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(New page: 200px<br /><applet load="1ut3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ut3" /> '''SOLUTION STRUCTURE OF SPHENISCIN-2, A BETA-D...)
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Revision as of 02:11, 21 November 2007
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SOLUTION STRUCTURE OF SPHENISCIN-2, A BETA-DEFENSIN FROM PENGUIN STOMACH PRESERVING FOOD
Overview
Recently two beta-defensins, named spheniscins, have been isolated from, the stomach content of the king penguin (Aptenodytes patagonicus), which, is capable of preserving food for several weeks during egg incubation, (Thouzeau, C., Le Maho, Y., Froget, G., Sabatier, L., Le Bohec, C., Hoffmann, J. A., and Bulet, P. (2003) J. Biol. Chem. 278, 51053-51058). It, has been proposed that, in combination with other antimicrobial peptides, spheniscins may be involved in this long term preservation of food in the, bird's stomach. To draw some structure/function features, the, three-dimensional structure in aqueous solution of the most abundant, spheniscin (Sphe-2) was determined by two-dimensional NMR and molecular, modeling techniques. The overall fold of Sphe-2 includes a three-stranded, antiparallel beta-sheet stabilized by three disulfide bridges with a, pairing typical of beta-defensins. In addition, the N-terminal segment, shows helical features on most structures. Sphe-2 is highly cationic, and, its surface displays a hydrophobic patch. Comparative modeling revealed, that this patch is preserved in avian defensins. The activity of Sphe-2, against a pathogenic Gram-positive strain was retained in vitro in the, conditions of osmolarity found in penguin stomach content and also in, different salt concentrations and compositions up to those reported for, seawater. Comparison with structurally related mammalian beta-defensins, showed that the hydrophobic patch is not preserved in mammalian, beta-defensins and that the high cationicity of Sphe-2 is presumably the, critical factor for its retained activity in high salt concentrations., Such peculiarities, in addition to a broad activity spectrum, suggest that, penguin defensins may represent interesting probes for the design of, highly efficient antibiotics to fight off pathogens that develop in, relatively salt-rich body fluids.
About this Structure
1UT3 is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Solution structure of spheniscin, a beta-defensin from the penguin stomach., Landon C, Thouzeau C, Labbe H, Bulet P, Vovelle F, J Biol Chem. 2004 Jul 16;279(29):30433-9. Epub 2004 Apr 30. PMID:15123713
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