A random flight chain model for the tether of the Shaker K+ channel inactivation domain.
Rapid inactivation of Shaker K+ channels occurs when a domain in the amino terminal region of the channel protein blocks the pore. Some part of the sequence between the inactivating domain and the first transmembrane segment may form a flexible tether. We consider the possibility that the tether has no secondary structure, but is rather a polypeptide random coil. The local concentration of the tethered inactivation domain and the dependence of the inactivation rate on chain length can then be calculated by using the Jacobson-Stockmayer equation. A chain of 30-100 amino acids is consistent with the sensitivity of the inactivation rate to chain length mutations.
Timpe
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LC
Program of Excellence in Molecular Biology, University of California, San Francisco 94143, USA.
Peller
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L
D000818:Animals; D046911:Macromolecular Substances; D008433:Mathematics; D008961:Models, Structural; D008962:Models, Theoretical; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000737:chemistry* / Q000502:physiology*; D011487:Protein Conformation; D011897:Random Allocation; D051637:Shaker Superfamily of Potassium Channels
D046911:Macromolecular Substances; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D051637:Shaker Superfamily of Potassium Channels