1BEI

Shk-dnp22: A Potent Kv1.3-specific immunosuppressive polypeptide, NMR, 20 structures

Summary for 1BEI

• Entry DOI: 10.2210/pdb1bei/pdb
• Descriptor: POTASSIUM CHANNEL TOXIN SHK (1 entity in total)
• Functional Keywords: potassium channel inhibitor, sea anemone, immunosuppressant neurotoxin
• Biological source: Stichodactyla helianthus
• Total number of polymer chains: 1
• Total formula weight: 4027.81

Authors

Kalman, K.,Pennington, M.W.,Lanigan, M.D.,Nguyen, A.,Rauer, H.,Mahnir, V.,Gutman, G.A.,Paschetto, K.,Kem, W.R.,Grissmer, S.,Christian, E.P.,Cahalan, M.D.,Norton, R.S.,Chandy, K.G. (deposition date: 1998-05-14, release date: 1998-12-02, Last modification date: 2022-12-21)

Primary citation

Kalman, K.,Pennington, M.W.,Lanigan, M.D.,Nguyen, A.,Rauer, H.,Mahnir, V.,Paschetto, K.,Kem, W.R.,Grissmer, S.,Gutman, G.A.,Christian, E.P.,Cahalan, M.D.,Norton, R.S.,Chandy, K.G.
ShK-Dap22, a potent Kv1.3-specific immunosuppressive polypeptide.
J.Biol.Chem., 273:32697-32707, 1998

PubMed Abstract: 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.

PubMed: 9830012
DOI: 10.1074/jbc.273.49.32697

Experimental method

SOLUTION NMR