FEBS Letters | |
Glycine 30 in iberiotoxin is a critical determinant of its specificity for maxi‐K versus KV channels | |
Mullmann, Theodore J1  Gao, Ying-Duo3  Giangiacomo, Kathleen M1  Garcia, Maria L2  Schmalhofer, W.A2  Schroeder, Nathan1  | |
[1] Department of Biochemistry, Temple University School of Medicine, 3420 N. Broad Street, Philadelphia, PA 19140, USA;Department of Membrane Biochemistry and Biophysics, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA;Molecular Systems, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA | |
关键词: Iberiotoxin; Maxi-K channel; KV1.3 channel; α-K peptide; Charybdotoxin; α-KTx; α-K peptide; ChTX or α-KTx 1.1; charybdotoxin; HgTX-1 or α-KTx 2.3; hongotoxin-1; IbTX or α-KTx 1.3; iberiotoxin; [125I]HgTX-1-A19Y/Y37F; mono-iodinated HgTX-1-A19Y/Y37F; [125I]IbTX-D19Y/Y36F; mono-iodinated IbTX-D19Y/Y36F; NxTX or α-KTx 2.1; noxiustoxin; K i; toxin inhibition constant; | |
DOI : 10.1016/S0014-5793(02)03256-8 | |
学科分类:生物化学/生物物理 | |
来源: John Wiley & Sons Ltd. | |
【 摘 要 】
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.
【 授权许可】
Unknown
【 预 览 】
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