Glycine 30 in iberiotoxin is a critical determinant of its specificity for maxi-K versus KVchannels
| Autor: | Kathleen M. Giangiacomo, Maria L. Garcia, Ying-Duo Gao, Theodore J. Mullmann, William A. Schmalhofer, Nathan E. Schroeder |
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| Rok vydání: | 2002 |
| Předmět: |
Potassium Channels
Charybdotoxin Protein Conformation Stereochemistry Molecular Sequence Data Glycine Biophysics Scorpion Venoms Peptide α-K peptide medicine.disease_cause Biochemistry Substrate Specificity Kv channel Potassium Channels Calcium-Activated chemistry.chemical_compound Structural Biology Genetics medicine Humans Amino Acid Sequence Large-Conductance Calcium-Activated Potassium Channels Molecular Biology Cells Cultured Toxins Biological chemistry.chemical_classification Kv1.3 Potassium Channel Sequence Homology Amino Acid Chemistry Toxin Mutagenesis Maxi-K channel Cell Biology Iberiotoxin Membrane Potassium Channels Voltage-Gated Mutation Asparagine Peptides KV1.3 channel |
| Zdroj: | FEBS Letters. 527:298-302 |
| ISSN: | 0014-5793 |
| Popis: | Iberiotoxin (IbTX) is a remarkably selective alpha-K toxin peptide (alpha-KTx) inhibitor of the maxi-K channel. In contrast, the highly homologous charybdotoxin inhibits both the maxi-K and K(V)1.3 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 K(V)1.3 channels were monitored through dose-dependent displacement of specifically bound iodinated alpha-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. |
| Databáze: | OpenAIRE |
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