Use of Bombyx mori Mutants to Study on Insect Biochemistry

威尔斯实验室从家蚕中肠中分离到叶黄素结合蛋白（40 kDa）。Fuji还从Y+^I蚕的中肠中分离并鉴定了类胡萝卜素结合蛋白（600 kDa）。该蛋白与血淋巴中的CBP在免疫学上的相似性和生化特性上的一致性都是一致的，YI蚕的中肠含有黄色蛋白，而Y+^I蚕的中肠不含。色素为类胡萝卜素。但该蛋白与CBP抗体不发生反应。因此，它是一个新的类胡萝卜素结合蛋白，而不是CBP。用抗CBP抗体克隆了编码CBP的cDNA，获得了几个克隆。对其中两个克隆进行了核苷酸序列分析，但与CBP不完全相同。家蚕中肠和中部丝腺类胡萝卜素结合蛋白（CBP）的免疫细胞化学分析。免疫胶体金技术显示CBP定位于粗面内质网和与光滑内质网相连的小泡中;类胡萝卜素通过胞吐作用从中肠分泌到血淋巴中，形成类胡萝卜素结合CBP复合物，然后从血淋巴中掺入到丝腺中部，最后转化为丝胶蛋白，再排出丝胶蛋白颗粒。LTP具有三种载脂蛋白（占颗粒质量的79%）：apoLTP-Ⅰ，apoLTP= Ⅱ，apoLTP= Ⅲ，Mr=350，000，85，000和60，000。LTP的脂质成分为磷脂（54%）、甘油单酯（8.3%）、甘油二酯（17%）、游离脂肪酸（14.3%）、甘油三酯（5.9%）和碳氢化合物（0.4%）。

Wells lab isolated lutein bound protein (40kDa) from the midgut of silkworm. Fuji also isolated and characterized carotinoid binding proitein (600kDa) from the midgut of the Y+^I silkworm. This protein is identical with CBP in hemolymph on the bisis of immunological similarity and the same biochemical properties as to CBP.The midgut of the YI silkworm contained a yellow colored protein, but did not in the Y+^I silkworm. The color pigment was carotinoid. But the protein did not react with anti-CBP antibody. Hence it is a new carotinoid binding protein other than CBP.cDNA library from the midgut of the Y+^I silkworm was constracted. cDNA encoding CBP has been cloned by using anti-CBP antibody and several clones were obtained. Two clones were analyzed nucleotide sequence, but they were not identical to CBP.Immunocytochemical analysis of carotinoid binding protein (CBP) in the midgut and middle silkgland of silkworm, Bombyx mori. Immunogold technique showed that CBP was located in rough ER,and in the small vesicle associated with smooth ER.Carotinoid was secreated into hemolymph from midgut as carotinoid bound CBP complex by exocytosis, incorporated into the middle part of silkgland from hemolymph as the complex and finally tansferrd to sericin prior to excretion of sericine particles.A lipid transfer particles (LTP) has been purified from the hemolymph of Bombyx mori. the LTP has three apoproteins (79% of particles mass) apo LTP-I,apoLTP=IInd apoLTP=III,Mr=350,000,85,000and 60,000. The lipid of LTP is phosphalipid (54%), monoacylgicerol (8.3%), diaacylglycerol (17%), free fatty acid (14.3%), triacylglycerol (5.9%) and hydrocarbon (0.4%).This protein is able to catalyze the transfer of a number of lipids among different lipid particle.