Voltage controlled ion channel

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Voltage-activated ion channels (or voltage-gated ion channels ) are transmembrane proteins , which in the membrane forming ion permeable pores varies depending on the membrane potential open or close. These channels contain charged amino acids that can be shifted across the membrane by changes in the electrical field . Each cation channel has six hydrophobic segments in six subunits each. The subunits one to four form the "voltage sensor", the subunits five to six surround the pore and determine the ion selectivity. The changes in the electric field lead to a conformational change of the protein and thus to an opening or closing.

Electrically excitable cells such as neurons are rich in voltage-activated ion channels .

literature

  • Y. Murata, H. Iwasaki, M. Sasaki, K. Inaba, Y. Okamura: Phosphoinositide phosphatase activity coupled to an intrinsic voltage sensor. In: Nature. 435 (7046), 2005, pp. 1239-1243. doi: 10.1038 / nature03650 . PMID 15902207 .
  • AA Alabi, MI Bahamonde, HJ Jung, JI Kim, KJ Swartz: Portability of paddle motif function and pharmacology in voltage sensors. In: Nature. 450 (7168), Nov. 2007, pp. 370-375. doi: 10.1038 / nature06266 . PMC 2709416 (free full text). PMID 18004375 .
  • SB Long, X. Tao, EB Campbell, R. MacKinnon: Atomic structure of a voltage-dependent K + channel in a lipid membrane-like environment. In: Nature. 450 (7168), November 2007, pp. 376-382. doi: 10.1038 / nature06265 . PMID 18004376 .

Individual evidence

  1. ↑ -Y Jiang, A Lee, J Chen, V Ruta, M Cadene, BT Chait & R MacK-innon. X-ray structure of a voltage-dependent K + chan-nel. Nature (2003) 423: 33-41, p. 33f.