Activation process of the mosquitocidal δ-endotoxin Cry39A produced by Bacillus thuringiensis subsp. aizawai BUN1-14 and binding property to Anopheles stephensi BBMV

Most δ-endotoxins produced by Bacillus thuringiensis require proteolytic processing in order to become active. The in vitro and in vivo activation processes of Cry39A, a δ-endotoxin that is highly toxic to Anopheles stephensi, were investigated. Cry39A with a molecular mass of 72 kDa was processed i...

Full description

Saved in:
Bibliographic Details
Published in:Journal of invertebrate pathology 2006-09, Vol.93 (1), p.29-35
Main Authors: Ito, Takeshi, Bando, Hisanori, Asano, Shin-ichiro
Format: Article
Language:English
Subjects:
amino acid sequences
Animals
Anopheles - drug effects
Anopheles - growth & development
Anopheles stephensi
Bacillus thuringiensis
Bacillus thuringiensis - genetics
Bacillus thuringiensis - metabolism
Bacillus thuringiensis subsp. aizawai
BBMV
binding properties
Binding Sites
brush border membrane vesicles
crystal proteins
delta-endotoxins
Endotoxins - biosynthesis
Endotoxins - genetics
Endotoxins - toxicity
Freshwater
In Vitro Techniques
insecticidal proteins
Microvilli - metabolism
molecular weight
Mosquito
Pest Control, Biological
Processing
Protein Binding
proteolysis
proteolytic processing
protoxins
toxin activation
Transport Vesicles - metabolism
δ-Endotoxin
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Most δ-endotoxins produced by Bacillus thuringiensis require proteolytic processing in order to become active. The in vitro and in vivo activation processes of Cry39A, a δ-endotoxin that is highly toxic to Anopheles stephensi, were investigated. Cry39A with a molecular mass of 72 kDa was processed in vitro into a 60 kDa fragment by trypsin and gut extract from A. stephensi larvae. N-terminal amino acid sequencing of the 60 kDa fragment revealed that trypsin and the protease(s) in the gut extract cleaved Cry39A between Arg 61 and Gly 62. In contrast, 40 and 25 kDa polypeptides were generated in vivo by intramolecular cleavage of the 60 kDa fragment in A. stephensi larvae. Further, a co-precipitation assay was used to investigate the binding property of the activated Cry39A to A. stephensi BBMV. Cry39A bound to A. stephensi BBMV specifically and did not compete with the Cry4Aa toxin. This indicated that the binding molecule(s) for Cry39A might differ from those for Cry4A. In addition, Cry39A preferentially bound to the Triton X-100-insoluble membrane fraction.
ISSN:0022-2011
1096-0805
DOI:10.1016/j.jip.2006.05.007