Developmental control of amino acid metabolism in the silkworm, Bombyx mori

1.本文通过测定家蚕脂肪体组织中尿素酶的活性，探讨了人工饲料饲养的家蚕血淋巴中尿素浓度比鲜桑叶饲养的高两倍的原因。2.以五龄幼虫为材料，研究了脂肪体中尿素酶的测定条件。3.从五龄幼虫开始至六龄幼虫结束，测定了脂肪体中尿素酶的活性。4.从五龄幼虫开始至六龄幼虫结束，测定了脂肪体中尿素酶的活性。5.从五龄幼虫开始至六龄幼虫结束，测定了脂肪体中尿素酶的活性。5.从五龄幼虫开始至六龄幼虫结束，测定了脂肪体中尿素酶的活性。5.从五龄幼虫开始至六龄幼虫结束，测定了脂肪体中尿素酶的活性。6.从五龄幼虫开始至六龄幼虫结束，测定了脂肪体中尿素酶的活性。7.从五龄幼虫开始，测定了脂肪体中尿素酶的活性。7.从五龄幼虫开始，测定了脂肪体中尿素酶的活性。8.从五龄幼虫开始，测定了脂肪体中尿素酶的活性。8.从用人工饲料和鲜桑叶饲养的家蚕，在羽化前一天进行蛹期测定，结果表明，两种饲料饲养的家蚕在羽化前一天蛹期的活动变化相似，都是在五龄幼虫中期达到高峰。5.每毫克脂肪体蛋白的Argian酶活性在人工饲料和鲜桑叶饲养的幼虫中的变化趋势相似。每只昆虫的蛋白质含量较高的幼虫饲养在人工饲料。这些结果表明，家蚕脂肪体合成的蛋白质中可能含有丝氨酸蛋白酶。6.家蚕脂肪体丝氨酸蛋白酶的亚细胞定位研究表明，丝氨酸蛋白酶定位于线粒体基质中。这一结果与普遍认为的细胞中的酶定位相反。产氨动物在线粒体基质中分解。线粒体内膜中的排尿酸动物酶。细胞质中的排尿动物胰蛋白酶。进一步的研究应该会揭开这个谜团。

1.The reason why two fold higher urea concentrations in the haemolymph in the silkworm larvae reared on an artificial diet result than those reared on fresh mulberry leaves was investigated by measuring arginase activity in the fat body tissue.2.Assay conditions for arginase in the fat body was studied using the tissues from the fifth instar larvae.3.Fat body arginase activity was measured from the beginning of the fifth instar larvae until the pupae at one day before adult emergence using insects reared on an artigicial diet and on fresh mulberry leaves.Silkworms reared on either diet showed similar activity changes with a peak at the middle of the fifth instar larvae. Silkworms reared on an artificial diet showed two fold higher activity per individual insect basis than those reared on fresh mulberry leaves.5.Argianse activity per mg fat body protein showed similar changes in the level both in the larvae reared on an artificial diet and on fresh mulberry leaves. Protein content per individual insect basis was higher in the larvae reared on an artificial diet. These results suggest that proteins synthesized in the fat body in response to intake of an artificial diet involves arginase in it.6.Subcellular localization studies indicated that arginase of silkworm larval fat body localized in mitochondrial matrix. This result was in contrast to the widespread belief of arginase localization in cells. Ammonotelic animal arginse in the mitochondrial matrix. Uricotelic animal arginase in mitochondrial innnermembrane. Ureotelic animal arginase in cytosol. Further studies should unveil the mystery.