Imperatoxin A, a Cell-Penetrating Peptide from Scorpion Venom, as a Probe of Ca-Release Channels/Ryanodine Receptors.

ABSTRACT: Scorpion venoms are rich in ion channel-modifying peptides, which have proven to be invaluable probes of ion channel structure-function relationship. We previously isolated imperatoxin A (IpTxa), a 3.7 kDa peptide activator of Ca(2+)-release channels/ryanodine receptors (RyRs) [1,2,3] and founding member of the calcin family of scorpion peptides. IpTxa folds into a compact, mostly hydrophobic molecule with a cluster of positively-charged, basic residues polarized on one side of the molecule that possibly interacts with the phospholipids of cell membranes. To investigate whether IpTxa permeates external cellular membranes and targets RyRs in vivo, we perfused IpTxa on intact cardiomyocytes while recording field-stimulated intracellular Ca(2+) transients. To further investigate the cell-pene

SUBMITTER: Gurrola GB 

PROVIDER: S-EPMC2910439 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature