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Identification of unknown components in insect prophenoloxidase activating system.

昆虫酚氧化酶激活系统中未知成分的鉴定。

基本信息

批准号：
15570059
负责人：
OCHIAI Masanori
金额：
$ 2.05万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15570059/
关键词：
insect biologocal defense innate immunity nonself recognition protease prophenoloxidase activating system

项目摘要

The prophenoloxidase (proPO) cascade of insect hemolymph is important for melanization around microbes invading the organisms and for recognition of foreignness. The cascade is triggered by microbial cell wall components such as β-1,3-glucan from fungi and peptidoglycan from bacteria. Although the interaction of peptidoglycan recognition protein (PGRP-S1) and peptidoglycan is thought to initiate a chain of enzymatic reactions in the peptidoglycan-mediated pathway of the cascade, the activating mechanism of the pathway has not been worked out yet. In this research the followings were made clear.1.I demonstrated that Gram-negative bacteria-binding protein (GNBP) is an essential component of the peptidoglycan-mediated pathway in the proPO cascade of the silkworm, Bombyx mori and this protein does not directly bind to the peptidoglycan but bind to a complex of the peptidoglycan and PGRP-S1, forming a ternary complex. These results indicate that GNBP works together with PGRP-S1 for the recognition of bacterial peptidoglycan in insect innate immunity.2.I purified a new essential component, Factor H, of the cascade from the silkworm plasma. The component could interacted with the ternary complex of peptidoglycan, PGRP-S1 and GNBP, and activates by itself, followed by the activation of a protease zymogen, Factor S. From analysis of internal sequences of Factor H, this protein was revealed to contain few sushi domains and a serine protease domain, suggesting that it is a novel zymogen of serine protease.3.The effects of addition of polysaccharides and Ca^<2+>-regulatory protein to protease activity were systematically investigated for stabilization of Factor H. β-Cyclodextrin-sulfate and calmodulin-binding protein inhibited thrombin activity as a noncompetitive inhibition, suggesting that there are a possibility of suppressing spontaneous activation of Fatcor H.

昆虫血淋巴的酚氧化酶原(ProPO)级联对于入侵生物体的微生物周围的黑化和异物的识别是重要的。这种级联反应是由微生物细胞壁成分触发的，例如来自真菌的β-1，3-葡聚糖和来自细菌的肽聚糖。尽管肽聚糖识别蛋白(PGRP-S1)和肽聚糖的相互作用被认为在肽聚糖介导的级联反应途径中启动了一连串的酶反应，但该途径的激活机制尚未弄清楚。本研究主要做了以下几方面的工作：1.证明革兰氏阴性细菌结合蛋白(GNBP)是家蚕肽聚糖途径的重要组成部分，该蛋白不直接与肽聚糖结合，而是与肽聚糖和PGRP-S1形成三元复合体。这些结果表明，GNBP与PGRP-S1一起识别昆虫天然免疫中的细菌肽聚糖。2.我从家蚕血浆中纯化了级联蛋白的一个新的必需成分--因子H。该组分能与肽聚糖、PGRP-S1和GNBP的三元复合体相互作用，并自行激活，随后激活一个蛋白酶原因子S。对因子H的内部序列分析表明，该蛋白含有很少的寿司结构域和一个丝氨酸蛋白酶结构域，表明它是一种新的丝氨酸蛋白酶的酶原。3.多糖和钙离子的作用；β-环糊精-硫酸盐和钙调蛋白结合蛋白抑制凝血酶活性是一种非竞争性抑制，提示存在抑制Fatcor H自发激活的可能性。

项目成果

期刊论文数量（21）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Effects of Mono-, Oligo- and Polysaccharides on Fibrin Gelation

单糖、寡糖和多糖对纤维蛋白凝胶化的影响

DOI：
发表时间：
2004
期刊：
Trans. MRS-J. 29
影响因子：
0
作者：
MURAMOTO K;KATO-NEGISHI M;KURODA Y;KOBA H;ICHIKAWA M;Kaya M.et al.;Ichikawa M;Masuda Y. et al.
通讯作者：
Masuda Y. et al.

Kogure, H.: "Effect of saccharides on the fibrinogen-fibrin conversion by thrombin"Trans.MRS-J.. 28. 949-952 (2003)

Kogure，H.：“糖类对凝血酶对纤维蛋白原-纤维蛋白转化的影响”Trans.MRS-J.. 28. 949-952 (2003)