Structure of the Subunit Protein of Bipyramidal δ-Endotoxin Produced by Bacillus thuringiensis kurstaki Strain HD-1

概要

論文の詳細を見る
The structure of the subunit protein of the bipyramidal δ-endotoxin of Bacillus thuringiensis kurstaki strain HD-1 was analyzed by limited hydrolysis with a gut juice protease (P-III) of the silkworm, Bombyx mori, and by neutralization tests using subunit protein IgG. The molecular weight of the subunit protein was 130, 000 by SDS-polyacrylamide gel electrophoresis. Hydrolysis of the subunit protein by P-III produced a toxic protein with 60, 000 dalton (P-59) and nontoxic peptides. A preparation of subunit IgG was put through P-59-agarose affinity chromatography, and the adsorbed fraction (TR-IgG) was separated. The unadsorbed fraction was reapplied to a subunit protein-agarose affinity column, and the adsorbed fraction (FR-IgG) was obtained. TR-IgG was capable of reacting to both subunit protein and P-59, and neutralized the toxicity of subunit protein. FR-IgG reacted to subunit protein but not to P-59. The toxicity of subunit protein was not neutralized by FR-IgG. These results indicate that the subunit protein is composed of protease-resistant region with a molecular weight of about 60, 000 and a residual protease-sensitive nontoxic region, which was surmised to be involved in the construction of the crystalline inclusion. Purified P-59 appeared to be a mixture of two protein species with similar molecular weights but with different charges.
社団法人日本農芸化学会の論文