| Structural highlights
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
The structure in solution of cardiotoxin III, a membrane toxin purified from the venom of the Taiwan cobra, Naja naja atra, is reported. Sequence-specific assignment of 1H-NMR lines was completed and the NMR data show the presence of a triple and a double-stranded antiparallel beta-sheet. Many NOE cross peaks identified in NOESY spectra were applied as distance constraints based on a hybrid distance geometry/dynamical simulated annealing technique; 20 structures were found within a single family. The average value of atomic RMS differences between the 20 structures and their geometric mean is 0.087 nm for the backbone atoms and 0.152 nm for all heavy atoms; they are 0.055 nm and 0.12 nm, respectively for the segments of secondary structure. In these selected structures the backbone of the polypeptide chain folds such that five strands emerge from a globular head. Three major loops link these strands to form a double and a triple-stranded antiparallel beta-sheet. Comparison of the structures of the toxin in solution with the X-ray crystal structure of its homologous protein, cardiotoxin V4II from Naja mossambica mossambica, showed good agreement between the structures except at segments of the turns. As the functions of short neurotoxins and cardiotoxins are distinct, despite their similar secondary structural patterns and tertiary folding, a comparative analysis has been carried out between cardiotoxin III and short neurotoxins of known structures. We discuss their structural features in order to clarify relationships between their structure and function.
Cardiotoxin III from the Taiwan cobra (Naja naja atra). Determination of structure in solution and comparison with short neurotoxins.,Bhaskaran R, Huang CC, Chang DK, Yu C J Mol Biol. 1994 Jan 28;235(4):1291-301. PMID:8308891[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
- ↑ Bhaskaran R, Huang CC, Chang DK, Yu C. Cardiotoxin III from the Taiwan cobra (Naja naja atra). Determination of structure in solution and comparison with short neurotoxins. J Mol Biol. 1994 Jan 28;235(4):1291-301. PMID:8308891 doi:http://dx.doi.org/10.1006/jmbi.1994.1082
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