Characterization of recognition specificity and analysis of variety of recognition proteins of BT toxin.

对3种BT毒素（苏云金芽孢杆菌三角洲内毒素）的携带靶点和结合特性进行了研究，结果如下：三种BT毒素与一些蛋白质结合，这些蛋白质在昆虫细胞上看不到，但用作实验试剂。三种BT毒素的结合蛋白基本相同。2. BT毒素与结合蛋白的亲和力比BT毒素与受体的亲和力低约100倍。3. 三种BT毒素均与牛红细胞碳酸酐酶和牛胰脏rna酶A结合。这些结合蛋白具有高度同源性的氨基酸序列，形成α -螺旋。4. 结果表明，BT毒素与用于与昆虫细胞受体结合的部分的结合蛋白结合。5. 结果表明，三种BT毒素中的一种利用氨肽酶N作为家蚕中肠细胞的受体。

Three BT toxins (delta-endotoxins of Bacillus thuringiensis) were investigated on their bringing targets and binding characters, and results were gained as follows.1. Three BT toxins bound to some proteins which is not seen on the insect cells but used as experimental reagents. Binding-proteins of the three BT toxines was almost the same each other. 2. Affinity of BT toxins and the binding-proteins were about 100 times lowere than that of BT toxins and their receptors. 3. All three BT toxins bound to carbonic anhydorase from bovine red blood cell and RNase A from bovine pancrae. These binding-proteins have amino acid sequences with high homology each other, which form alpha-helicses. 4. It was shown that BT toxin bind to the binding-proteins on the portion which is used to bind to the insect cell receptors. 5. It was suggested that one of three BT toxins utilise aminopeptidase N as a receptor on the silkworm midgut cells.