The toxic moiety of the Bacillus thuringiensis protoxin undergores a conformational change upon activation

Proteolytic processing of the 133-kDa crystal protein (protoxin) from Bacillus thuringiensis subsp. kurstaki yields a 67-kDa insecticidal toxin. Differential scanning calorimetry was used to investigate whether the toxic moiety in the protoxin molecule has the same conformation as activated toxin. C...

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Bibliographic Details
Published inBiochemical and biophysical research communications Vol. 179; no. 2
Main Authors Choma, C.T. (University of Ottawa, Ottawa, Ontario, Canada), Surewicz, W.K, Kaplan, H
Format Journal Article
LanguageEnglish
Published 16.09.1991
Subjects
BACILLUS THURINGIENSIS
PROTEOLISIS
PROTEOLYSE
TOXINAS
TOXINE
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Summary:Proteolytic processing of the 133-kDa crystal protein (protoxin) from Bacillus thuringiensis subsp. kurstaki yields a 67-kDa insecticidal toxin. Differential scanning calorimetry was used to investigate whether the toxic moiety in the protoxin molecule has the same conformation as activated toxin. Compared to protoxin, toxin gives rise to a more complex endotherm which extends over a 10 degrees C broader temperature range and contains a component occurring at a substantially higher temperature than any unfolding transition in the protoxin endotherm. It is concluded that the toxic moiety undergoes a conformational change upon activation in which the thermal stability of at least one of its domains is significantly increased
Bibliography:9171294
H10
L72
ISSN:0006-291X
1090-2104