Sivropoulou A, Haritidou L, Vasara E, Aptosoglou S, Koliais S
Laboratory of General Microbiology, Section of Genetics, Development and Molecular Biology, School of Biology, Aristotle University, Thessaloniki 54006, Greece.
Curr Microbiol. 2000 Oct;41(4):262-6. doi: 10.1007/s0028432708.
The crystals of the soil-isolated Bacillus thuringiensis (Bt) strain A4 consist of two polypeptides with molecular mass of 140 kDa and 32 kDa that exhibit insecticidal activity against adult flies of Bactrocera oleae (Diptera). Plasmid curing applied to this strain resulted in the isolation of several subclones exhibiting alterations in their crystal polypeptides as well as two acrystalliferous subclones. The crystals of subclone 1.1 lacked the 32-kDa polypeptide and consisted uniquely of a 140-kDa polypeptide antigenically related to the parental 140-kDa crystal polypeptide. Additionally, the crystals of this subclone exhibited insecticidal activity against B. oleae equivalent to that of the parental strain. Therefore, the 32-kDa crystal polypeptide is dispensable for insecticidal activity, which appears to be dependent on the presence of the 140-kDa crystal polypeptide.
从土壤中分离得到的苏云金芽孢杆菌（Bt）菌株A4的晶体由分子量分别为140 kDa和32 kDa的两种多肽组成，它们对油橄榄实蝇（双翅目）成虫具有杀虫活性。对该菌株进行质粒消除后，分离出了几个晶体多肽发生改变的亚克隆以及两个无晶体亚克隆。亚克隆1.1的晶体缺少32 kDa的多肽，仅由与亲本140 kDa晶体多肽具有抗原相关性的140 kDa多肽组成。此外，该亚克隆的晶体对油橄榄实蝇的杀虫活性与亲本菌株相当。因此，32 kDa的晶体多肽对于杀虫活性是可有可无的，杀虫活性似乎取决于140 kDa晶体多肽的存在。
