Binding of Bacillus thuringiensis Cry1Ac toxin to Manduca sexta aminopeptidase‐N receptor is not directly related to toxicity

FEBS Letters

Sangadala, Sreedhara³  Adang, Michael J.³  Lee, Mi Kyong²  Jenkins, Jeremy L.¹  Dean, Donald H.¹ 

[1] Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA;Department of Biochemistry, The Ohio State University, 484 W. 12th Ave., Columbus, OH 43210, USA;Department of Entomology, University of Georgia, Athens, GA 30602-2603, USA

关键词: Aminopeptidase-N;    Brush border membrane vesicle;    Surface plasmon resonance;    N-Acetylgalactosamine;    Bacillus thuringiensis;   

DOI  :  10.1016/S0014-5793(99)01559-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Bacillus thuringiensis Cry1Ac δ-endotoxin specifically binds a 115-kDa aminopeptidase-N purified from Manduca sexta midgut. Cry1Ac domain III mutations were constructed around a putative sugar-binding pocket and binding to purified aminopeptidase-N and brush border membrane vesicles (BBMV) was compared to toxicity. Q509A, R511A, Y513A, and 509–511 (QNR-AAA) eliminated aminopeptidase-N binding and reduced binding to BBMV. However, toxicity decreased no more than two-fold, indicating activity is not directly correlated with aminopeptidase-N binding. Analysis of toxin binding to aminopeptidase-N in M. sexta is therefore insufficient for predicting toxicity. Mutants retained binding, however, to another BBMV site, suggesting alternative receptors may compensate in vivo.

【 授权许可】

Unknown