Agitoxin 1

from Wikipedia, the free encyclopedia
Potassium channel toxin alpha-KTx 3.4
other names

Agitoxin-1

Mass / length primary structure 38 amino acids , 4,021 Da
Identifier
External IDs

Agitoxin 1 (synonym potassium channel toxin alpha-KTx 3.4 ) is a neurotoxin from the scorpion Leiurus quinquestriatus hebraeus (yellow Mediterranean scorpion ).

properties

Agitoxins 1 to 3 in comparison

Agitoxin 1 is a protein and scorpion toxin from the yellow Mediterranean scorpion , as are agitoxin 2 , agitoxin 3 , chlorotoxin , charybdotoxin a , charybdotoxin b and scyllatoxin . The three agitoxins each consist of 38 amino acids with three disulfide bridges , are largely identical and differ in four positions (7, 15, 29, 31). It binds and inhibits the potassium channel shaker in Drosophila and its homologues in mammals Kv1.3 / KCNA3 ( K i = 1.7 nM ), Kv1.1 / KCNA1 (K i = 136 nM) and Kv1.6 / KCNA6 (K i = 149 nM), but not Kv2.1 / KCNB1 . Arginine at positions 24 and 31 and a lysine at position 27 are essential for inhibiting Shaker . The agitoxins were first isolated in 1994. They are structurally most closely related to potassium toxin 1 and potassium toxin 2 .

Web links

Individual evidence

  1. ↑ AM Krezel, C. Kasibhatla, P. Hidalgo, R. MacKinnon, G. Wagner: Solution structure of the potassium channel inhibitor agitoxin 2: caliper for probing channel geometry. In: Protein science: a publication of the Protein Society. Volume 4, number 8, August 1995, pp. 1478-1489, doi : 10.1002 / pro.5560040805 , PMID 8520473 , PMC 2143198 (free full text).
  2. ↑ ML Garcia, M. Garcia-Calvo, P. Hidalgo, A. Lee, R. MacKinnon: Purification and characterization of three inhibitors of voltage-dependent K + channels from Leiurus quinquestriatus var. Hebraeus venom. In: Biochemistry. Volume 33, Number 22, June 1994, pp. 6834-6839, PMID 8204618 .
  3. ^ Hervé Rochat: Animal Toxins. Springer Science & Business Media, 2000, ISBN 978-3-764-35983-6 , p. 184.