Memoirs of the Faculty of Engineering, Okayama University 36巻 2号
2002-03 発行
Yamagiwa, Masashi
Department of Bioscience and Biotechnology, Okayama University
Namba, Akitoshi
Department of Bioscience and Biotechnology, Okayama University
Akao, Tetsuyuki
Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center
Mizuki, Eiichi
Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center
Ohba, Michio
Graduate School of Agriculture, Kyusyu University
The crystal proteins produced by Bacillus thuringiensis subsp, israelensis (Bti) and subsp. coreanensis A1519 strain were examined for the cytotoxicity against MOLT-4 and HeLa cells by MTT assay and LDH assay, The A1519 crystal proteins processed by proteinase K exhibited the specific cell-killing activity toward MOLT-4 with little damage to the cell membrane, On the other hand, the Bti crystal proteins processed by proteinase K caused the substantial damage to the cell membrane of both MOLT-4 and HeLa, leading to the cell lysis. The non-digested crystal proteins of both strains exhibited no cytotoxicity, These data suggested that while the Bti crystal proteins caused the colloid-osmotic swelling and cell lysis of MOLT-4 and HeLa, the proteinase K-digested A1519 crystal proteins induced the specific cell death of MOLT-4 through a mechanism other than that of Bti.
