Molecular property and functional control of chaperone-like polymer

类伴侣聚合物的分子特性及功能调控

基本信息

批准号：
16550109
负责人：
TANAKA Naoki
金额：
$ 2.37万
依托单位：
Kyoto Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

The irreversible protein denaturation due to the aggregation is serious problem in the research of protein structure. Molecular chaperones, member of heat shock protein, prevent the protein aggregate in vivo through the weak protein integration. It has been shown that phospholipid polymers (MPC polymer) also weakly interact proteins, and we used these polymers as the artificial molecular chaperone. We have design several MPC copolymers, and screened by there chaperone-like activity. The activity for the refolding of β-galactosidase, malate dehydrogenase, MHC Class II, luciferase GFP and rhodanese have been examined. The copolymer with butylmethacrylate (PMB polymer) showed high performance for the refolding of these proteins.The in vitro protein synthesis is one of the effective methods for this purpose, but this method has weak point of the low yield. To construct a highly efficient in vitro protein synthesis system, the effects PMB polymer were examined. Although PMB polymer showed chaperone-like activity, the yield of rhodanese in the in vitro protein synthesis was not enhanced by this polymers. Another new design of the MPC polymer is necessary for the efficient in vitro protein synthesis system. Furthermore, we examined the effect of MPC copolymers on the amyloid fibril formation of insulin. We found that hydrophilic copolymers accelerated the amyloid formation rate, and the hydrophobic copolymers reduced the total amount of amyloid fibril. But so far, MPC copolymers don't have sufficient ability to control amyloid fibril structure. We will improve the functional capability of MPC copolymer by the arrangement of copolymerization ratio and molecular weight.

聚集引起的不可逆蛋白质变性是蛋白质结构研究中的一个严重问题。磷脂聚合物（MPC聚合物）是热休克蛋白的成员，它通过弱蛋白质整合来阻止蛋白质在体内聚集。也弱相互作用的蛋白质，我们使用这些聚合物作为人工分子伴侣，我们设计了几种MPC共聚物，并通过其类伴侣活性进行筛选。已经检测了β-半乳糖苷酶、苹果酸脱氢酶、MHC II类、荧光素酶GFP和硫氰酸酶的重折叠，与甲基丙烯酸丁酯的共聚物（PMB聚合物）对这些蛋白质的重折叠表现出高性能。体外蛋白质合成是有效的方法之一。为此，该方法存在产量低的缺点，为了构建高效的体外蛋白质合成系统，尽管PMB聚合物显示了其效果，但该方法仍存在收率低的缺点。尽管具有分子伴侣样活性，但该聚合物并未提高体外蛋白质合成中硫氰酸酶的产量，这对于有效的体外蛋白质合成系统是必要的。此外，我们还研究了 MPC 共聚物对体外蛋白质合成的影响。我们发现亲水性共聚物加速了淀粉样蛋白的形成速度，而疏水性共聚物则减少了淀粉样蛋白原纤维的总量。共聚物对淀粉样原纤维结构的控制能力不强，我们将通过共聚比例和分子量的安排来提高MPC共聚物的功能能力。