Synthesis of cyclic peptides containing His and its possibility of brain activating

哺乳动物脑内下丘脑合成的垂体促性腺激素释放激素有TRH、LHRH、CRH、GHRH等，其中TRH和LHRH这两种小分子多肽在结构上具有相似性。两种肽均具有pyroGlu作为N-末端氨基酸、His和氨基酸酰胺作为C-末端。我们已经明确，在大鼠脑内存在焦戊酰肽酶，该酶可合成环肽组氨酰脯氨酸二酮哌嗪。这种环肽被认为是一种大脑激活物质。在这种情况下，我们合成了四种含组氨酸的环肽，并成功地制备了针对每种环肽的特异性抗体。利用这些抗体，我们希望建立微量测定和免疫组化方法，以明确肽在脑内的分布。除此之外，我们还想利用垂体细胞培养和蛋白质印迹方法了解环肽的垂体激素释放能力。两年的时间对这个项目来说是不够的。我们现在需要更多的时间，环肽作为脑激活物质的可能性需要动物体内实验。本项目最初计划由4名成员参与，但有2名成员被调动，无法加入本项目。只有两个成员开始了这个项目（后来另一个加入）。所以，我们现在要抓紧时间。

Pitutitary hormone-releasing hormones which are synthesized in the hypothalamus of the mammalian brain are now known as TRH,LHRH,CRH,GHRH,and so on. Among them, low molecular weight peptides, TRH and LHRH show the structural similarities. Both peptides have pyroGlu as N-terminal amino acid, His, and amino acid amide as C-terminal. We have already cleared that there is pyrogrutamyl peptidase in rat brain and the protease makes cyclic peptide ; histidyl-proline diketopiperazine. This cyclic peptide is supposed to behave as a brain activating substance. Biological activities of the releasing-hormones which show many functions including brain activating ability might be due to the cyclic peptides.Under the circumstances we synthesized four peptides which contain His, then succeeded in making antibodies which have specificities against each cyclic peptide. Using the antibodies we wanted to develop the microdetermination and immunohistochemical methods which can clear the peptide distribution in the brain. Besides those, using pituitary cell culture and western blotting methods, we wanted to know the pituitary hormonereleasing abilities of cyclic peptides. Two years was not enough for this project. We now need more time, and the possibility of cyclic peptides as brain activating substances needs the experiments using animals in vivo.This project was planned among 4 members at first, but two members were tranferred and were not able to join this project. Only 2 members started this project (afterwards another joined). So, we now making haste.