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Structure and Activity of Fish Growth Hormones

鱼类生长激素的结构和活性

基本信息

批准号：
59860021
负责人：
KAWAUCHI Hiroshi
金额：
$ 7.36万
依托单位：
Kitasato University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1984
资助国家：
日本
起止时间：
1984 至 1986
项目状态：
已结题

项目摘要

This investigation characterized the growth stimulating potential of growth hormones (GH) isolated form two species of economically important fish. GHs purified from an alkaline extract of chum salmon (Oncorhynchus keta) pituitary glands and from a culture medium of eel (Anguilla japonica) pituitary glands were chemically characterized. cDNA clones encoding these fish GHs were isolated from cDNA libraries prepared from pituitary gland poly(A) <^+RNAs> , using synthetic DNAs corresponding to the amino acid sequence of the hormones. The cDNAs of salmon and eel GH were cloned and expressed in E. coli. Salmon and eel GHs synthesized by genetically engineered bacteria (recombinant GHs) had potency equivalent to the natural GHs. Salmonid growth could be stimulated by intraperitoneal injections at doses of 10-100ng/g body weight.Possible routes for administration of these hormones to fish were investigated. Immersion of salmonid fish into solution of the recombinant salmon GH stimulated the g … More rowth at concentrations of 0.15 to 1.5 <micro> M. Furthermore, oral administration of the recombinant salmon GH could stimulate growth of young rainbow trout at a dose of 10 <micro> g/fish. The blood level of GH, detected by salmon GH radioimmunoassay. increased significantly at 15-18 hour after the administration.It was also confirmed that GHs play an important role in regulating osmotic pressure of seawater-adapting fish, while prolactin (PRL) regulates osmotic pressure in freshwater-adapting fish.A second major goal of our work was to study structure-function relationships of the important regulatory hormone. Since PRLs show close chemical resemblance to GH, they have been thought to have evolved from a common ancestral molecule by gene duplication. In order to obtain better insight into the molecular evolution or structure-function relationships. fish PRLs were also characterized. The sequence comparisons of GHs and PRLs showed the occurrence of conserved structures, suggesting that they may be responsible for their biological activities. On the basis of the sequence comparison, the time of divergence of GH and PRL from the common ancestral molecule was estimated to be about 500 million years ago. Less

这项研究表征了从两种重要经济鱼类中分离出的生长激素 (GH) 的生长刺激潜力。对从鲑鱼 (Oncorhynchus keta) 垂体腺碱性提取物和鳗鱼 (Anguilla japonica) 垂体腺培养基中纯化的 GH 进行了化学表征。使用与激素的氨基酸序列相对应的合成DNA，从由垂体poly(A)<^+RNA>制备的cDNA文库中分离编码这些鱼GH的cDNA克隆。克隆了鲑鱼和鳗鱼 GH 的 cDNA，并在大肠杆菌中表达。由基因工程细菌（重组 GH）合成的鲑鱼和鳗鱼 GH 具有与天然 GH 相当的效力。腹腔注射10-100ng/g体重的剂量可以刺激鲑鱼的生长。研究了向鱼类施用这些激素的可能途径。将鲑科鱼浸入重组鲑鱼 GH 溶液中，浓度为 0.15 至 1.5 µM 时可刺激生长。此外，口服重组鲑鱼 GH 可以刺激幼年虹鳟鱼的生长，剂量为 10 µg/条。采用鲑鱼GH放射免疫法检测血液中GH水平。给药后15-18小时显着增加。还证实GH在调节海水适应鱼类的渗透压中发挥重要作用，而催乳素（PRL）调节淡水适应鱼类的渗透压。我们工作的第二个主要目标是研究重要调节激素的结构与功能关系。由于 PRL 的化学性质与 GH 非常相似，因此它们被认为是通过基因复制从共同的祖先分子进化而来的。为了更好地了解分子进化或结构功能关系。还对鱼类 PRL 进行了表征。 GH 和 PRL 的序列比较显示了保守结构的出现，表明它们可能负责其生物活性。根据序列比较，GH和PRL与共同祖先分子的分化时间估计约为5亿年前。较少的