TY - JOUR
T1 - Shk-Dap22, a potent Kv1.3-specific immunosuppressive polypeptide
AU - Kalman, Katalin
AU - Pennington, Michael W.
AU - Lanigan, Mark D.
AU - Nguyen, Angela
AU - Rauer, Heiko
AU - Mahnir, Vladimir
AU - Paschetto, Kathy
AU - Kem, William R.
AU - Grissmer, Stephan
AU - Gutman, George A.
AU - Christian, Edward P.
AU - Cahalan, Michael D.
AU - Norton, Raymond S.
AU - Chandy, K. George
PY - 1998/12/4
Y1 - 1998/12/4
N2 - 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 κ200 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.
AB - 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 κ200 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.
UR - http://www.scopus.com/inward/record.url?scp=0032483810&partnerID=8YFLogxK
U2 - 10.1074/jbc.273.49.32697
DO - 10.1074/jbc.273.49.32697
M3 - Article
C2 - 9830012
AN - SCOPUS:0032483810
VL - 273
SP - 32697
EP - 32707
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 1083-351X
IS - 49
ER -