1i02

NMR STRUCTURE OF CTX A3 AT NEUTRAL PH (20 STRUCTURES)

spinqualitylabelsall models 1i02, 20 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1i02 is a 1 chain structure with sequence from Naja atra. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 1cb9, 1cdt, 2cdx, 2crt, 1kxi, 1tgx Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [3SA3_NAJAT] Basic protein that binds to cell membrane and depolarizes cardiomyocytes. This cytotoxin also possesses lytic activity on many other cells, including red blood cells (PubMed:8182052). Interaction with sulfatides in the cell membrane induces pore formation and cell internalization. Cytotoxicity is due to pore formation, and to another mechanism independent of membrane-damaging activity. When internalized, it targets the mitochondrial membrane and induces mitochondrial swelling and fragmentation. It inhibits protein kinases C. It binds to the integrin alpha-V/beta-3 (ITGAV/ITGB3) with a moderate affinity (PubMed:16407244). It also binds with high affinity to heparin (PubMed:17685633). 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 Recent studies of cobra P-type cardiotoxins (CTXs) have shown that the water-binding loop (loop II) plays a crucial role in toxin binding to biological membranes and in their cytotoxicity. To understand the role of bound water in the loop, the structure and dynamics of the major P-type CTX from Taiwan cobra, CTX A3, were determined by a comprehensive NMR analysis involving (1)H NOESY/ROESY, (13)C[1)H]NOE/T(1) relaxation, and (17)O triple-quantum filtered NMR. A single water molecule was found to be tightly hydrogen bonded to the NH of Met26 with a correlation time (5-7 ns) approaching the isotropic tumbling time (3.8-4.5 ns) of the CTX A3 molecule. Surprisingly, despite the relatively long residence time (ca. 5 ns to 100 micros), the bound water molecule of CTX A3 is located within a dynamic (order parameter S(2) approximately 0.7) and solvent accessible loop. Comparison among several P-type CTXs suggests that proline residues in the consensus sequence of MxAxPxVPV should play an important role in the formation of the water binding loop. It is proposed that the exchange rate of the bound water may play a role in regulating the lipid binding mode of amphiphilic CTX molecules near membrane surfaces. Dynamic characterization of the water binding loop in the P-type cardiotoxin: implication for the role of the bound water molecule.,Sue SC, Jarrell HC, Brisson JR, Wu WG Biochemistry. 2001 Oct 30;40(43):12782-94. PMID:11669614 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cardiotoxin 3D structures

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