title: Jingzhaotoxin-XII, a gating modifier specific for Kv4.1 channels.
abstract: Jingzhaotoxin-XII (JZTX-XII), a 29-residue polypeptide, was purified from the venom of the Chinese tarantula Chilobrachys jingzhao. Electrophysiological recordings carried out in Xenopus laevis oocytes showed that JZTX-XII is specific for Kv4.1 channels, with the IC50 value of 0.363 microM. It interacts with the channels by modifying the gating behavior. JZTX-XII shares 80% sequence identity with phrixotoxin1, a potent inhibitor for Kv4.2 and Kv4.3 channels. Structure analysis indicates that the difference of the charge distribution in the interactive surface perhaps influences the specific pharmacology of the toxins. JZTX-XII should be a valuable tool for the investigation of the Kv4.1 channels.
authors.affiliation: Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, Life Science College, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Chunhua
authors.initials: C
authors.lastname: Yuan
authors.forename: Zhi
authors.initials: Z
authors.lastname: Liao
authors.forename: Xiongzhi
authors.initials: X
authors.lastname: Zeng
authors.forename: Longjun
authors.initials: L
authors.lastname: Dai
authors.forename: Fang
authors.initials: F
authors.lastname: Kuang
authors.forename: Songping
authors.initials: S
authors.lastname: Liang
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D015640:Ion Channel Gating / Q000187:drug effects*; D015394:Molecular Structure; D009865:Oocytes / Q000187:drug effects; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D051669:Shab Potassium Channels; D051672:Shal Potassium Channels / Q000187:drug effects* / Q000378:metabolism; D013111:Spider Venoms / Q000737:chemistry*; D013329:Structure-Activity Relationship; D014982:Xenopus laevis
chemical_list: D010455:Peptides; D026902:Potassium Channel Blockers; D051669:Shab Potassium Channels; D051672:Shal Potassium Channels; D013111:Spider Venoms