Restriction of intramolecular movements within the Cry1Aa toxin molecule of Bacillus thuringiensis through disulfide bond engineering

FEBS Letters

Préfontaine, Gabrielle¹  Masson, Luke¹  Schwartz, Jean-Louis¹  Cygler, Miroslaw¹  Juteau, Marc¹  Brousseau, Roland¹  Grochulski, Pawel¹ 

[1] Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2, Canada

关键词: Cry1Aa;    Planar lipid bilayer;    Ion channel;    Disulfide bridge;    Bacillus thuringiensis;   

DOI  :  10.1016/S0014-5793(97)00626-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Disulfide bridges were introduced into Cry1Aa, a Bacillus thuringiensis lepidopteran toxin, to stabilize different protein domains including domain I α-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 β-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 α-helices 4 and 5 in domain I plays a critical role in the formation of a functional pore.

【 授权许可】

Unknown