Research for a basic anti-microbial recognition system of the animal using silkworm, Bombyx mori

用微生物细胞亲和纯化从家蚕幼虫血淋巴中获得抗微生物识别蛋白。家蚕。用大肠杆菌细胞纯化了一个43 kDa的脂多糖结合蛋白，命名为BmLBP。BmLBP通过识别脂质A与多种革兰氏阴性菌结合，帮助血细胞形成结节。cDNA克隆和测序结果表明，BmLBP是c型凝集素超家族的新成员，具有独特的结构特征，由两个不同的碳水化合物识别结构域串联组成。用宫颈酵母菌细胞和黄体微球菌细胞分别纯化了两个42 kDa的蛋白。两者都通过识别细菌细胞壁的碳水化合物结合细菌。同时，它们需要钙来结合。从这些特征可以推测出两种蛋白是c型凝集素。构建了针对这三种结合蛋白的抗血清，并对它们进行了密切反应性检测。结果表明，从宫颈酵母菌细胞和黄体微球菌细胞中获得的两种蛋白在selology上是相同的，而BmLBP则与这两种蛋白不同。从这些结果可以推测，只有两种凝集素足以识别相当广泛的微生物。

Affinity purification was conducted with microbial cells to obtain anti-microbial recognition proteins from the larval hemolymph of the silkworm. Bombyx mori.A 43 kDa lipopolysaccharide-binding protein was purified with Esherichia coli cells and named BmLBP. BmLBP bound to many kinds of gram-negative bacteria by recognition of lipid A and helped nodule formation of the blood cells. From the result of cDNA cloning and sequencing it was shown that BmLBP is a novel member of the C-type lectin superfamily with a unique structural feature that consists of two different carbohydrate-recognition domains in tandem.Two proteins of 42 kDa were purified respectively with Saccharomyces cervisiae cells and Micrococcus luteus cells. Both bound bacteria by recognizing carbohydrate of the bacterial cell wall. Also, they needed calcium in binding. From these characters two protein were assumed to be C-type lectins.Antisera were constructed against these three binding proteins and closs-reactivity was tested each other. As a result, two protein obtained with Saccharomyces cervisiae cells and Micrococcus luteus cells were shown to be selologically the same and BmLBP was shown to be different from these two proteins. From these results it was supposed that only two kinds of lectin is sufficient to recognize fairly broad range of microorganisms.