ShK-Dap22, a Potent Kv1.3-specific Immunosuppressive Polypeptide
| Autor: | Heiko Rauer, K. Kalman, Kathy Paschetto, Angela Nguyen, Edward P. Christian, Michael D. Cahalan, George A. Gutman, William R. Kem, Raymond S. Norton, Michael W. Pennington, V.M. Mahnir, K. George Chandy, Mark D. Lanigan, Stephan Grissmer |
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| Rok vydání: | 1998 |
| Předmět: |
Male
Models Molecular Magnetic Resonance Spectroscopy Potassium Channels T-Lymphocytes Molecular Sequence Data Mutant Peptide Pharmacology medicine.disease_cause Biochemistry Protein Structure Secondary Cell Line Mice medicine Animals Humans Amino Acid Sequence Molecular Biology chemistry.chemical_classification Kv1.3 Potassium Channel Toxin Cell Biology Recombinant Proteins In vitro Potassium channel Amino acid chemistry Potassium Channels Voltage-Gated Docking (molecular) Peptides Immunosuppressive Agents Potassium Channel Binding |
| Zdroj: | Journal of Biological Chemistry. 273:32697-32707 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.273.49.32697 |
| Popis: | The voltage-gated potassium channel in T lymphocytes, Kv1.3, is an important molecular target for immunosuppressive agents. A structurally defined polypeptide, ShK, from the sea anemone Stichodactyla helianthus inhibited Kv1.3 potently and also blocked Kv1.1, Kv1.4, and Kv1.6 at subnanomolar concentrations. Using mutant cycle analysis in conjunction with complementary mutagenesis of ShK and Kv1.3, and utilizing the structure of ShK, we determined a likely docking configuration for this peptide in the channel. Based upon this topological information, we replaced the critical Lys22 in ShK with the positively charged, non-natural amino acid diaminopropionic acid (ShK-Dap22) and generated a highly selective and potent blocker of the T-lymphocyte channel. ShK-Dap22, at subnanomolar concentrations, suppressed anti-CD3 induced human T-lymphocyte [3H]thymidine incorporation in vitro. Toxicity with this mutant peptide was low in a rodent model, with a median paralytic dose of approximately 200 mg/kg body weight following intravenous administration. The overall structure of ShK-Dap22 in solution, as determined from NMR data, is similar to that of native ShK toxin, but there are some differences in the residues involved in potassium channel binding. Based on these results, we propose that ShK-Dap22 or a structural analogue may have use as an immunosuppressant for the prevention of graft rejection and for the treatment of autoimmune diseases. |
| Databáze: | OpenAIRE |
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