1ro3

New structural insights on short disintegrin echistatin by NMRNew structural insights on short disintegrin echistatin by NMR

Structural highlights 1ro3 is a 1 chain structure with sequence from Echis carinatus. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 2ech Resources: FirstGlance, OCA, RCSB, PDBsum Function [DISI_ECHCA] Potent inhibitor of ligand binding to the integrins alpha-V/beta-3 (ITGAV/ITGB3), alpha-5/beta-1 (ITGA5/ITGB1) and alpha-IIb/beta-3 (ITGA2B/ITGB3). Competition with fibrinogen for the RGD recognition sites on the alpha-IIb/beta-3 integrin (glyco-protein IIb/IIIa complex) results in the inhibition of platelet aggregation and other antithrombotic properties such as an ability to prevent coronary thrombosis in animal models. Is also a potent inhibitor of bone resorption. This results from the blocking of the interaction of alpha-V/beta-3 integrin on the surface of osteoclasts with bone extracellular matrix. In addition, interaction with alpha-V/beta-3 also inhibits adhesion of human umbilical vein endothelial cells (HUVEC) to immobilized vitronectin and fibronectin. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Echistatin is a potent antagonist of the integrins alpha(v)beta3, alpha5beta1 and alpha(IIb)beta3. Its full inhibitory activity depends on an RGD (Arg-Gly-Asp) motif expressed at the tip of the integrin-binding loop and on its C-terminal tail. Previous NMR structures of echistatin showed a poorly defined integrin-recognition sequence and an incomplete C-terminal tail, which left the molecular basis of the functional synergy between the RGD loop and the C-terminal region unresolved. We report a high-resolution structure of echistatin and an analysis of its internal motions by off-resonance ROESY (rotating-frame Overhauser enhancement spectroscopy). The full-length C-terminal polypeptide is visible as a beta-hairpin running parallel to the RGD loop and exposing at the tip residues Pro43, His44 and Lys45. The side chains of the amino acids of the RGD motif have well-defined conformations. The integrin-binding loop displays an overall movement with maximal amplitude of 30 degrees . Internal angular motions in the 100-300 ps timescale indicate increased flexibility for the backbone atoms at the base of the integrin-recognition loop. In addition, backbone atoms of the amino acids Ala23 (flanking the R24GD26 tripeptide) and Asp26 of the integrin-binding motif showed increased angular mobility, suggesting the existence of major and minor hinge effects at the base and the tip, respectively, of the RGD loop. A strong network of NOEs (nuclear Overhauser effects) between residues of the RGD loop and the C-terminal tail indicate concerted motions between these two functional regions. A full-length echistatin-alpha(v)beta3 docking model suggests that echistatin's C-terminal amino acids may contact alpha(v)-subunit residues and provides new insights to delineate structure-function correlations. Conformation and concerted dynamics of the integrin-binding site and the C-terminal region of echistatin revealed by homonuclear NMR.,Monleon D, Esteve V, Kovacs H, Calvete JJ, Celda B Biochem J. 2005 Apr 1;387(Pt 1):57-66. PMID:15535803 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Disintegrin

spinqualitylabelsall models 1ro3, 20 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image