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Covalent structure and some pharmacological features of native and cleaved α‐KTx 12−1 , a four disulfide‐bridged toxin from Tityus serrulatus venom
Author(s) -
Pimenta A. M. C.,
Mansuelle P.,
Diniz C. R.,
MartinEauclaire M. F.
Publication year - 2003
Publication title -
journal of peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 66
eISSN - 1099-1387
pISSN - 1075-2617
DOI - 10.1002/psc.440
Subject(s) - peptide , venom , chemistry , disulfide bond , toxin , cleavage (geology) , peptide sequence , stereochemistry , biochemistry , molecular mass , covalent bond , scorpion toxin , amino acid , enzyme , biology , organic chemistry , scorpion , paleontology , fracture (geology) , gene
A toxin with four disulfide bridges from Tityus serrulatus venom was able to compete with 125 I‐kaliotoxin on rat brain synaptosomal preparations, with an IC 50 of 46 n M . The obtained amino acid sequence and molecular mass are identical to the previously described butantoxin. Enzymatic cleavages in the native peptide followed by mass spectrometry peptide mapping analysis were used to determine the disulfide bridge pattern of α‐KTx 12−1 . Also, after the cleavage of the first six N ‐terminal residues, including the unusual disulfide bridge which forms an N ‐terminus ring, the potency of the cleaved peptide was found to decrease about 100 fold compared with the native protein. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.