Abstract
Iberiotoxin (IbTX) is a remarkably selective α-K toxin peptide (α-KTx) inhibitor of the maxi-K channel. In contrast, the highly homologous charybdotoxin inhibits both the maxi-K and KV1.3 channels with similar high affinity. The present study investigates the molecular basis for this specificity through mutagenesis of IbTX. The interactions of mutated peptides with maxi-K and KV1.3 channels were monitored through dose-dependent displacement of specifically bound iodinated α-KTx peptides from membranes expressing these channels. Results of these studies suggest that the presence of a glycine at position 30 in IbTX is a major determinant of its specificity while the presence of four unique acidic residues in IbTX is not.
Original language | English (US) |
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Pages (from-to) | 298-302 |
Number of pages | 5 |
Journal | FEBS Letters |
Volume | 527 |
Issue number | 1-3 |
DOIs | |
State | Published - Sep 11 2002 |
Externally published | Yes |
Keywords
- α-K peptide
- Charybdotoxin
- Iberiotoxin
- K1.3 channel
- Maxi-K channel
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology