University of Sussex
Browse

File(s) not publicly available

N-terminal activation is an essential early step in the mechanism of action of Bacillus thuringiensis Cry1Ac insecticidal toxin

journal contribution
posted on 2023-06-08, 09:27 authored by Alejandra Bravo, Jorge Sánchez, Thaleia Kouskoura, Neil CrickmoreNeil Crickmore
A variant form of the Bacillus thuringiensis Cry1Ac toxin that is not cleaved at the N terminus during proteolytic activation with trypsin was found to be incapable of forming pores in Manduca sexta brush border membrane vesicles in vitro and had reduced insecticidal activity in vivo. Binding studies indicated an altered binding pattern of the mutant toxin in that bound toxin could not be fully displaced by a high molar excess of fully trypsin-activated toxin. These results suggest that proteolytic removal of the N-terminal peptide of Cry1Ac is an important step in toxin activation.

History

Publication status

  • Published

Journal

Journal of Biological Chemistry

ISSN

0021-9258

Issue

27

Volume

277

Page range

23985-23987

Pages

3.0

Department affiliated with

  • Biochemistry Publications

Notes

NC directed this work, mutant proteins were produced at Sussex by Kouskoura and Crickmore with specialised assays performed by collaborators in Mexico. The work describes an important role for the N-terminus of the Bt toxin with implications for GM crops which express these toxins.

Full text available

  • No

Peer reviewed?

  • Yes

Legacy Posted Date

2012-02-06

Usage metrics

    University of Sussex (Publications)

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC