{PDOC51862} {PS51862; BSPN_CSAB} {BEGIN} ****************************************************************************** * BetaSPN-type cysteine-stabilized alpha/beta (CS-alpha/beta) domain profile * ****************************************************************************** Scorpion venoms are complex mixture of peptides with a variety of pharmacological functions. These toxin peptides include ion channel modulators, antibacterial peptides, and protease inhibitors. Scorpion toxins targeting various ion channels share a cysteine-stabilized alpha/beta (CS- alpha/beta) structure, which can be divided into two types: short-chain toxins of 23–42 amino acid residues with 3 or 4 disulfide bridges, which are commonly potassium channel blockers, and long-chain toxins of 53–78 amino acids, which are mostly modulators of sodium channels. In addition to the classic short-chain toxins such as alpha-KTxs, which are specific for potassium channels, long-chain toxins with unique structure and function, which were named beta-KTxs and scorpine-like peptides, were identified from the scorpion families Buthidae, Scorpionidae and Caraboctonidae. Peptides of the betaSPN (beta-KTxs and scorpines) family, which are 59–75 amino acid residues in length, display various antimicrobial, cytolytic, and potassium channel-blocking activities. BetaSPN family full- length mature peptides contain two structural domains that confer them bi- functionality: the amphipathic alpha-helical N-terminal domain has cytolytic or antimicrobial activity, while the three-disulfid bridged C-terminal domain with the consensus CS-alpha/beta motif has K(+) channel blocking activity. Sequence analysis revealed that the BetaSPN family can be divided into three distinct groups: (1) beta-KTx-like peptides from buthids; (2) Scorpine-like peptides from Scorpionidae and Caraboctonidae species, including scorpine, Opiscorpines 1–4, HgeScplp1, HgeScplp2 and Heteroscorpine 1; (3) heterogeneous peptides similar to BmTXKbeta of buthids and iurids [1,2,3,4,5]. The betaSPN-type CS-alpha/beta domain is more closely related to invertebrate defensins, antimicrobial peptides involved in the innate immune response of several invertebrate groups (see ), than to the classical scorpion toxins. Its structure shows an alpha helix along with one beta sheet stabilized by three disulfide bridges, folding into a CS-alpha/beta motif (see ). The connectivity between the ordinal numbered cysteines is C1-C4, C2-C5, and C3-C6 [5]. The profile we developed covers the entire betaSPN-type CS-alpha/beta domain. -Sequences known to belong to this class detected by the profile: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: April 2018 / First entry. [ 1] Diego-Garcia E., Schwartz E.F., D'Suze G., Gonzalez S.A.R., Batista C.V.F., Garcia B.I., de la Vega R.C., Possani L.D. "Wide phylogenetic distribution of Scorpine and long-chain beta-KTx-like peptides in scorpion venoms: identification of 'orphan' components." Peptides 28:31-37(2007). PubMed=17141373; DOI=10.1016/j.peptides.2006.06.012 [ 2] Feng J., Yu C., Wang M., Li Z., Wu Y., Cao Z., Li W., He X., Han S. "Expression and characterization of a novel scorpine-like peptide Ev37, from the scorpion Euscorpiops validus." Protein Expr. Purif. 88:127-133(2013). PubMed=23262394; DOI=10.1016/j.pep.2012.12.004 [ 3] Luna-Martinez K., Jimenez-Vargas J.M., Possani L.D. "Scorpine-Like Peptides." Single Cell Biology 5(2016). DOI=10.4172/2168-9431.1000138 [ 4] Zhu S., Gao B., Aumelas A., del Carmen Rodriguez M., Lanz-Mendoza H., Peigneur S., Diego-Garcia E., Martin-Eauclaire M.-F., Tytgat J., Possani L.D. "MeuTXKbeta1, a scorpion venom-derived two-domain potassium channel toxin-like peptide with cytolytic activity." Biochim. Biophys. Acta 1804:872-883(2010). PubMed=20045493; DOI=10.1016/j.bbapap.2009.12.017 [ 5] Flores-Solis D., Toledano Y., Rodriguez-Lima O., Cano-Sanchez P., Ramirez-Cordero B.E., Landa A., Rodriguez de la Vega R.C., Del Rio-Portilla F. "Solution structure and antiparasitic activity of scorpine-like peptides from Hoffmannihadrurus gertschi." FEBS Lett. 590:2286-2296(2016). PubMed=27314815; DOI=10.1002/1873-3468.12255 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}