Gene expression, mutation, and structure-function relationship of scorpion toxin BmP05 active on SKCa channels

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	Gene expression, mutation, and structure-function relationship of scorpion toxin BmP05 active on SKCa channels
	Wu, JJ ; He, LL ; Zhou, Z ; Chi, CW
刊名	BIOCHEMISTRY
	2002
卷号	41 期号:8 页码:2844-2849
关键词	CA2+-ACTIVATED K+ CHANNELS ADRENAL CHROMAFFIN CELLS NUCLEAR-MAGNETIC-RESONANCE LEIUROTOXIN-I SCYLLATOXIN BUTHUS-MARTENSI KARSCH POTASSIUM CHANNELS GENOMIC ORGANIZATION VENOM PURIFICATION BLOCKER
ISSN号	0006-2960
通讯作者	Chi, CW (reprint author), Chinese Acad Sci, Shanghai Inst Biochem & Cell Biol, State Key Lab Mol Biol, Shanghai 200031, Peoples R China,
英文摘要	Four peptide inhibitors of small-conductance Ca2+-activated, apamin-sensitive K+ channels (SKCa) have been isolated from the venom of the Chinese scorpion Buthus martensi, named BmP01, BmP02, BmP03, and BmP05, respectively [Romi-Lebrun, R. (1997) Eur. J. Biochem. 245, 457-464]. Among them BmP05 with 31 amino acid residues has been intensively studied due to its most potent toxicity. To investigate the structure-function relationship of BmP05, its wild type and seven mutants (their C-termini unamidated) were successfully expressed in the yeast secretion system and purified with a high yield over 8 mg/L. Their toxicity to mice and electrophysiological activity on the K+ currents (SKCa and Kv) in rat adrenal chromaffin cells were measured and compared. The results indicated the following: (1) As a selective antagonist against SKCa, 1 muM rBmP05 is equivalent to 0.2 muM apamin, and its IC50 is 0.92 muM. (2) The basic residues Lys and Arg located at positions 6 and 13 in the N-terminal alpha-helix region are essential and synergetic in the interaction of the toxin with SKCa. (3) Disruption of the alpha-helix by mutation of Gln at position 9 with Pro results in almost total loss of toxicity. (4) The C-terminal residue His31 plays an auxiliary role in the interaction of the toxin with SKCa. (5) The beta-turn connecting two beta-sheets near the C-terminal part is responsible for the specificity of the toxin to the different subtypes of K+ channels.
学科主题	Biochemistry & Molecular Biology
收录类别	SCI
语种	英语
公开日期	2012-07-23
内容类型	期刊论文
源URL	[http://ir.sibs.ac.cn/handle/331001/2065]
专题	上海神经科学研究所_神经所(总)
推荐引用方式 GB/T 7714	Wu, JJ,He, LL,Zhou, Z,et al. Gene expression, mutation, and structure-function relationship of scorpion toxin BmP05 active on SKCa channels[J]. BIOCHEMISTRY,2002,41(8):2844-2849.
APA	Wu, JJ,He, LL,Zhou, Z,&Chi, CW.(2002).Gene expression, mutation, and structure-function relationship of scorpion toxin BmP05 active on SKCa channels.BIOCHEMISTRY,41(8),2844-2849.
MLA	Wu, JJ,et al."Gene expression, mutation, and structure-function relationship of scorpion toxin BmP05 active on SKCa channels".BIOCHEMISTRY 41.8(2002):2844-2849.