The effect of a proteinase trapping agent, alpha-2-macroglobulin, on the activity of immuno- and neural cells

蛋白酶捕获剂 α-2-巨球蛋白对免疫细胞和神经细胞活性的影响

基本信息

批准号：
04454592
负责人：
IKAI Atsushi
金额：
$ 0.51万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

Alpha-2-macroglobulin is a varsatile protease inhibitor that can inhibits the activity of a large variety of endoproteinases by a unique mechanism called the trap mechanism. The mechanism assumes that the cleavage of peptide bonds in the "bait region" of alpha-2-M triggers off a gequential intra-molecular reactions that finally causes a global change in the structure of alpha-2-M entrapping the proteinase. Determination of the rate of bait region hydrolysis and those of subsequent reactions including the structural change has been a key lsssue in the study of trap mechanism. In this study we have been successful in determining the rate of bait region cleavage and that of the global structural change for the first time.As the next accomplishment in this study, we tested our hypothesis that alpha-2-M can be used as an efficient carrier of peptide vaccines to antigen presenting cells such as macrophages. The peptide vaccine concept has been developed to eliminate the hazardous side effects of conventional vaccines derived from bio-materials. Chemically synthesized peptides are used in place of conventlonal vaccines but the low antigenicity of such peptides should be augmented. WE proposed that synthetic peptides can be conjugated to alpha-2-M and administered to host animals. The conjugate can be efficiently taken up by macrophages via receptor mediated endocytosis and eventually activates a high degree of antibody production. The of such experiment in this study has been very promising.The effect of alpha-2-M the cultured neurons has been examined in this study and the result was positlvely interpreted to show the neurite extension effect of alpha-2-M.The presence of alpha-2-M and its receptor in the brain tissue has been confirmed suggesting the observed activity of the protein could be physiologically important in the brain development.

Alpha-2-巨球蛋白是一种多功能蛋白酶抑制剂，可以通过称为陷阱机制的独特机制抑制多种内切蛋白酶的活性。该机制假设α-2-M“诱饵区域”中肽键的断裂引发了连续的分子内反应，最终导致捕获蛋白酶的α-2-M结构发生整体变化。诱饵区域水解速率以及包括结构变化在内的后续反应速率的测定一直是诱捕机理研究的关键问题。在这项研究中，我们首次成功地确定了诱饵区域裂解的速率和整体结构变化的速率。作为本研究的下一个成就，我们测试了我们的假设，即α-2-M可以用作诱饵区域裂解的速率。肽疫苗向抗原呈递细胞（例如巨噬细胞）的有效载体。肽疫苗概念的开发是为了消除源自生物材料的传统疫苗的危险副作用。使用化学合成肽代替传统疫苗，但应增强此类肽的低抗原性。我们提出合成肽可以与 α-2-M 缀合并施用于宿主动物。该缀合物可以通过受体介导的内吞作用被巨噬细胞有效吸收，并最终激活高度的抗体产生。本研究中此类实验的效果非常有前途。本研究检查了α-2-M对培养的神经元的影响，并对结果进行了积极的解释，显示了α-2-M的神经突延伸作用。 α-2-M 及其受体在脑组织中的存在已得到证实，表明观察到的该蛋白质的活性可能对大脑发育具有重要的生理意义。