2003/03/01 by David Sanders, Tanya Doherty, John Mason +4 · 1 citation
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Chemistry · Health Professions · Medicine · Nursing · #Adversary #Amino acid #Bacillus thuringiensis #Bacteria #Bioassay #Biochemistry #Biology #Botany #Chemistry #Child Nutrition and Water Access #Computer science #Computer security #Culex pipiens #Ecology #Entomopathogenic Microorganisms in Pest Control #Enzyme #Food Security and Health in Diverse Populations #Fusion protein #Gene #Genetics #Glutathione #Helix (gastropod) #Insect Resistance and Genetics #Insect and Pesticide Research #Larva #Medicine #Mutant #Recombinant DNA #Toxicity #Toxin #Viral gastroenteritis research and epidemiology
paper · doi:10.1016/s0140-6736(13)61633-5
openalex publication_date 2003/03/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/06/11
An active form of Cry4A is a heterodimer of the 20- and 45-kDa fragments that are derived from the 130-kDa Cry4A protoxin. To investigate the function of these two fragments, several deletion mutants were constructed and expressed in E.coli as the GST (glutathione-S-transf~rase) fusion proteins. The results of the bioassay against Culex pipiens larvae showed that the interaction of two fragments of Cry4A was necessary for the toxicity, and that the C-terminal 67 amino acids of the 20-kDa fragment corresponding to the helices a4 and a5 were involved in determining the insecticidal activity. Surprisingly the lack of helix a5 did not affect the toxicity to C. pipiens, suggesting that the role of helix a5 of Cry4A was different from that postulated in the case of Cry I A toxins. 1.