The mosquito larvicidal activity of 130 KDA delta-endotoxin of Bacillus thuringiensis var. israelensis resides in the 72 KDA amino-terminal fragment

Abstract

Bacillus thuringiensis var. israelensis produces 130 kDa delta-endotoxin which is highly toxic to mosquito-larvae. The mosquito-larvicidal activity was delineated by sequential deletions from ends of the 1136 amino acids delta-endotoxin. A maximum of 459 amino acids could be removed from the carboxy-terminal of the toxin without a significant loss of the larvicidal activity. However, no more than 38 amino acids could be deleted from the amino-terminal without losing the toxicity. The truncated peptide of 72. kDa exhibited similar toxicity to the 130 kDa toxin and was between 39 th and 677 th amino acids. © 1988 Academic Press, Inc.