Projects per year
Abstract
The voltage-gated potassium channel Kv1.3 is an important target for the treatment of autoimmune diseases and asthma. Blockade of Kv1.3 by the sea anemone peptide K+-channel toxin from Stichodactyla helianthus (ShK) inhibits the proliferation of effector memory T lymphocytes and ameliorates autoimmune diseases in animal models. However, the lack of selectivity of ShK for Kv1.3 over the Kv1.1 subtype has driven a search for Kv1.3-selective analogues. In the present study, we describe N-terminally extended analogues of ShK that contain a negatively-charged Glu, designed to mimic the phosphonate adduct in earlier Kv1.3-selective analogues, and consist entirely of common protein amino acids. Molecular dynamics simulations indicated that a Trp residue at position [-3] of the tetrapeptide extension could form stable interactions with Pro377 of Kv1.3 and best discriminates between Kv1.3 and Kv1.1. This led to the development of ShK with an N-terminal Glu-Trp-Ser-Ser extension ([EWSS]ShK), which inhibits Kv1.3 with an IC50 of 34 pm and is 158-fold selective for Kv1.3 over Kv1.1. In addition, [EWSS]ShK is more than 2900-fold more selective for Kv1.3 over Kv1.2 and KCa3.1 channels. As a highly Kv1.3-selective analogue of ShK based entirely on protein amino acids, which can be produced by recombinant expression, this peptide is a valuable addition to the complement of therapeutic candidates for the treatment of autoimmune diseases. The voltage-gated potassium channel Kv1.3 is an important target for the treatment of autoimmune diseases and asthma. Amongst the most potent inhibitors of Kv1.3 is the sea anemone toxin ShK - a peptide that blocks Kv1.3, inhibiting the proliferation of effector memory T lymphocytes. In this study, Chang and colleagues used computational techniques to design N-terminally extended analogues of ShK based on their structure-activity relationships with Kv1.3. One analogue, [EWSS]ShK, inhibits Kv1.3 with an IC50 of 34 pm, is highly selective for Kv1.3 over Kv1.1, Kv1.2 and KCa3.1 channels, and is therefore a potential candidate for the treatment of autoimmune diseases.
Original language | English |
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Pages (from-to) | 2247-2259 |
Number of pages | 13 |
Journal | The FEBS Journal |
Volume | 282 |
Issue number | 12 |
DOIs | |
Publication status | Published - 2015 |
Keywords
- electrophysiology
- molecular dynamics
- N-terminal extension
- potassium channels
- ShK
Projects
- 2 Finished
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New Peptides for the Treatment of Multiple Sclerosis
Norton, R. (Primary Chief Investigator (PCI))
NIH - National Institutes of Health (United States of America)
1/09/11 → 31/05/16
Project: Research
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NHMRC Research Fellowship
Norton, R. (Primary Chief Investigator (PCI))
National Health and Medical Research Council (NHMRC) (Australia)
1/01/09 → 31/12/18
Project: Research