Recombinant scorpion insectotoxin AaIT kills specifically insect cells but not human cells  

Recombinant scorpion insectotoxin AaIT kills specifically insect cells but not human cellss

作　　者：SHENG JIAN JI, FENG LIU, ER Qiu LI, Yu XIAN ZHUThe National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China 

出　　处：《Cell Research》2002年第2期143-150,共8页细胞研究（英文版）

基　　金：This work was supported by a grant from 863High Technology Program,Chinese Ministry of Sci-ence and Technology

摘　　要：The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was confirmed by N-terminal peptide sequencing. Two groups of bioassays, artificial diet incorporation assay and contact insecticidal effect assay, were carried out separately to verify the toxicity of this recombinant toxin. At the end of a 24 h experimental period, more than 60% of the testing diamondback moth (Plutella xylostella) larvae were killed in both groups with LC50 value of 18.4 microM and 0.70 microM respectively. Cytotoxicity assay using cultured Sf9 insect cells and MCF-7 human cells demonstrated that the toxin AaIT had specific toxicity against insect cells but not human cells. Only 0.13 microM recombinant toxin was needed to kill 50% of cultured insect cells while as much as 1.3 microM toxin had absolutely no effect on human cells. Insect cells produced obvious intrusions from their plasma membrane before broken up. We infer that toxin AaIT bind to a putative sodium channel in these insect cells and open the channel persistently, which would result in Na+ influx and finally cause destruction of insect cells.

关 键 词：Amino Acid Sequence Animals Base Sequence Biological Assay Cell Line Cloning  Molecular Dose-Response Relationship  Drug Electrophoresis  Polyacrylamide Gel Escherichia coli Humans Inhibitory Concentration 50 Insects Molecular Sequence Data Peptides Protein Structure  Tertiary Recombinant Proteins Research Support  Non-U.S. Gov't Scorpion Venoms Sequence Analysis  Protein Sodium Time Factors Tumor Cells  Cultured 

分 类 号：Q784[生物学—分子生物学]