8.B.12.1.5 Omega-ctenitoxin-Pn4a (CnTx-Pn4a; neurotoxin Tx3-6; α1-β toxin) of 90 aas and 1 N-terminal TMS. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. It is a potent blocker of high voltage-activated calcium
channels, acting mainly on P/Q-type (Cav2.1/CACNA1A) calcium channels
and with a minor effect on L- (Cav1/CACNA1) and N-type (Cav2.2/CACNA1B)
calcium channels (Vieira et al. 2005). It blocks glutamate release in synaptic transmission
mediated by calcium channels (Vieira et al. 2003). The toxin also inhibits the KCl-induced
increase of intrasynaptosomal free calcium (Souza et al. 2008).
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Accession Number: | P81792 |
Protein Name: | Omega-ctenitoxin-Pn4a |
Length: | 90 |
Molecular Weight: | 9926.00 |
Species: | Phoneutria nigriventer (Brazilian armed spider) [6918] |
Location1 / Topology2 / Orientation3: |
Secreted1 |
Substrate |
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1: MKCAVLFLSV IALVHIFVVE AEEEPDSDAL VPQERACIPR GEICTDDCEC CGCDNQCYCP
61: PGSSLGIFKC SCAHANKYFC NRKKEKCKKA