| 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).[1] [2] [3] [4] [5] [6] [7]
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[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Wang CH, Wu WG. Amphiphilic beta-sheet cobra cardiotoxin targets mitochondria and disrupts its network. FEBS Lett. 2005 Jun 6;579(14):3169-74. PMID:15922335 doi:http://dx.doi.org/S0014-5793(05)00579-X
- ↑ Wang CH, Liu JH, Lee SC, Hsiao CD, Wu WG. Glycosphingolipid-facilitated membrane insertion and internalization of cobra cardiotoxin. The sulfatide.cardiotoxin complex structure in a membrane-like environment suggests a lipid-dependent cell-penetrating mechanism for membrane binding polypeptides. J Biol Chem. 2006 Jan 6;281(1):656-67. Epub 2005 Nov 1. PMID:16263708 doi:10.1074/jbc.M507880200
- ↑ Wu PL, Lee SC, Chuang CC, Mori S, Akakura N, Wu WG, Takada Y. Non-cytotoxic cobra cardiotoxin A5 binds to alpha(v)beta3 integrin and inhibits bone resorption. Identification of cardiotoxins as non-RGD integrin-binding proteins of the Ly-6 family. J Biol Chem. 2006 Mar 24;281(12):7937-45. Epub 2006 Jan 10. PMID:16407244 doi:http://dx.doi.org/M513035200
- ↑ Chen KC, Kao PH, Lin SR, Chang LS. The mechanism of cytotoxicity by Naja naja atra cardiotoxin 3 is physically distant from its membrane-damaging effect. Toxicon. 2007 Nov;50(6):816-24. Epub 2007 Jun 27. PMID:17714752 doi:http://dx.doi.org/S0041-0101(07)00224-3
- ↑ Chien KY, Chiang CM, Hseu YC, Vyas AA, Rule GS, Wu W. Two distinct types of cardiotoxin as revealed by the structure and activity relationship of their interaction with zwitterionic phospholipid dispersions. J Biol Chem. 1994 May 20;269(20):14473-83. PMID:8182052
- ↑ Chiou SH, Raynor RL, Zheng B, Chambers TC, Kuo JF. Cobra venom cardiotoxin (cytotoxin) isoforms and neurotoxin: comparative potency of protein kinase C inhibition and cancer cell cytotoxicity and modes of enzyme inhibition. Biochemistry. 1993 Mar 2;32(8):2062-7. PMID:8448165
- ↑ Sue SC, Rajan PK, Chen TS, Hsieh CH, Wu W. Action of Taiwan cobra cardiotoxin on membranes: binding modes of a beta-sheet polypeptide with phosphatidylcholine bilayers. Biochemistry. 1997 Aug 12;36(32):9826-36. PMID:9245415 doi:http://dx.doi.org/10.1021/bi970413l
- ↑ Sue SC, Jarrell HC, Brisson JR, Wu WG. Dynamic characterization of the water binding loop in the P-type cardiotoxin: implication for the role of the bound water molecule. Biochemistry. 2001 Oct 30;40(43):12782-94. PMID:11669614
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