Restriction of intramolecular movements within the Cry1Aa toxin molecule of Bacillus thuringiensis through disulfide bond engineering.
FEBS Lett
; 410(2-3): 397-402, 1997 Jun 30.
Article
em En
| MEDLINE
| ID: mdl-9237670
ABSTRACT
Disulfide bridges were introduced into CrylAa, a Bacillus thuringiensis lepidopteran toxin, to stabilize different protein domains including domain I alpha-helical regions thought to be involved in membrane integration and permeation. Bridged mutants could not form functional ion channels in lipid bilayers in the oxidized state, but upon reduction with beta-mercaptoethanol, regained parental toxin channel activity. Our results show that unfolding of the protein around a hinge region linking domain I and II is a necessary step for pore formation. They also suggest that membrane insertion of the hydrophobic hairpin made of alpha-helices 4 and 5 in domain I plays a critical role in the formation of a functional pore.
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Base de dados:
MEDLINE
Assunto principal:
Bacillus thuringiensis
/
Proteínas de Bactérias
/
Toxinas Bacterianas
/
Dissulfetos
/
Endotoxinas
Idioma:
En
Ano de publicação:
1997
Tipo de documento:
Article