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Triflin is a toxin derived from snake venom. The toxin is produced in the gland of the Habu snake, Trimeresurus flavoviridis . [1]
Triflin is a cysteine-rich secretory protein (CRISP), which is excreted by the venom gland of the Habu snake ( Trimeresurus flavoviridis ). [1] Triflin reduces high potassium-induced smooth muscle contraction, suggesting a blocking effect on L-type calcium channels. [2]
Triflin is a toxin derived from snake venom. The toxin is produced in the gland of the Habu snake, Trimeresurus flavoviridis . [1]
Triflin is a cysteine-rich secretory protein, which means it belongs to the CRISP family. This is a group of single chain polypeptides found in various organisms. Triflin weighs 25 kDa and consists of 221 amino-acid residues. The first 163 residues of the N-terminal domain forms an α-β-α sandwich core. This domain is comparable with group 1 plant pathogenesis-related protein (PR-1). The C-terminal domain, has five disulfide bridges. This domain is responsible for the selectivity of the protein and consists of two subdomains: N-terminal subdomain (Cys 167 to Cys 179) and C-terminal subdomain (42 amino-acids residues). The N-terminal subdomain is connected with N-terminal domain through two main-chain hydrogen bonds between β11 and β2 and is thereby part of the PR-1 domain. The C-terminal subdomain is stabilized by three disulfide bridges and it is remarkable that this domain does not interact with either the PR-1 domain or the N-terminal sub-domain. The C-terminal subdomain consists of particles, including some hydrophobic residues that are exposed to the solvent. These hydrophobic residues might mediate the interaction with the target proteins and therefore receptor recognition. [1]
There are some homologous toxins to Triflin with different percentages of amino-acid sequence similarity, such as Ablomin, Latisemin, Stecrip (88%), Helothermine (49%), [2] Pseudechetoxin (62%), Pseudesin (61%). [3] The snake venoms which belong to CRISP family seem to be homologous to each other, however there are differences in their protein targets. [1]
Triflin reduces high potassium induced smooth muscle contraction, suggesting a blocking effect on L-type calcium channels. [2]
One of the small serum proteins (SSP-2), a substance produced by Trimeresurus flavoviridis itself, has high affinity for Triflin, and may thus work as a defensive mechanism against accidental self-poisoning, suggesting a possible role for SSP-2 as an antidote to triflin. [4]
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