Cardiotoxin III

Cytotoxin 3
Identifiers
OrganismNaja atra
Symbol?
PDB1H0J
UniProtP60301
Search for
StructuresSwiss-model
DomainsInterPro

Cardiotoxin III (CTX III, also known as cytotoxin 3) is a sixty amino-acid polypeptide toxin from the Taiwan cobra Naja atra. CTX III is highly basic and hydrophobic protein.[1] It is an example of a group of snake cardio/cytotoxins (InterPro: IPR003572), which are made up of shorter snake venom three-finger toxins. Over 50 different cytotoxin polypeptides have been isolated and sequenced from venom samples. The difference in the CTX functionality may be due to the relatively small difference in the polypeptide's structure, allowing different CTXs to induce lysis in different cell types.[2] The CTX III molecule contains multiple binding sites and is cytolytic for myocardial cells and human leukemic T cells.[3]

CTX III's molecular structure displays a folding of the polypeptide backbone that creates five stands from a globular structure. These strands form a double and a triple antiparallel β-sheet.[4] Studies performed with an antibody complementary of CTX III seemed to conclude that the active site for the molecule's hemolytic and cytotoxic functions and characteristics result from two separate sites.

  1. ^ Su, Shu-Hui; Su, Shu-Jem; Lin, Shinne-Ren; Chang, Kee-Lung (November 2003). "Cardiotoxin-III selectively enhances activation-induced apoptosis of human CD8+ T lymphocytes". Toxicology and Applied Pharmacology. 193 (1): 97–105. doi:10.1016/S0041-008X(03)00327-2. PMID 14613720.
  2. ^ Ménez, A.; Gatineau, E.; Roumestand, C.; Harvey, A.L.; Mouawad, L.; Gilquin, B.; Toma, F. (August 1990). "Do cardiotoxins possess a functional site? Structural and chemical modification studies reveal the functional site of the cardiotoxin from Naja nigricollis". Biochimie. 72 (8): 575–588. doi:10.1016/0300-9084(90)90121-v. ISSN 0300-9084. PMID 2126462.
  3. ^ Sivaraman, T.; Kumar, T. K. S.; Huang, C. C.; Yu, C. (January 1998). "The role of acetic acid in the prevention of salt-induced aggregation of snake venom cardiotoxins". IUBMB Life. 44 (1): 29–39. doi:10.1080/15216549800201032. ISSN 1521-6543. PMID 9503145. S2CID 28326180.
  4. ^ Bhaskaran, Rajagopalan; Huang, Chung Chih; Chang, Ding Kwo; Yu, Chin (1994-01-27). "Cardiotoxin III from the Taiwan Cobra (Naja naja atra): Determination of Structure in Solution and Comparison with Short Neurotoxins". Journal of Molecular Biology. 235 (4): 1291–1301. doi:10.1006/jmbi.1994.1082. ISSN 0022-2836. PMID 8308891.