Studies on human osteopontin : isolation and characterization of osteopontin in milk and serum.

人骨桥蛋白的研究：牛奶和血清中骨桥蛋白的分离和表征。

基本信息

批准号：
09557062
负责人：
KOBAYASHI Kunihiko
金额：
$ 5.89万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09557062/
关键词：
osteopontin Ca-binding human milk human serum molecular fragility Ca結合蛋白母乳血清

项目摘要

Osteopontin (hereafter called as OPN), a CaィイD12+ィエD1 binding protein, has been studied as a secreted highly acidic phophoglycoprotein with diverse functions in various tissue and species. It was firstly isolated from mineralized bone matrix and studied as a protein remodeling mineralized tissue. Since OPN is present in human milk, we considered that the OPN plays an important role in the osteogenesis in the developing infants. The present studies aimed to isolate and characterize OPN in human milk, serum and blood cells.We have isolated osteopontin from human milk, prepared antibodies specific for it, and tried to establish a sandwich type EIA system determining osteopontin in serum. It was found that serum osteopontin but not milk osteopontin showed paradoxical phenomena in reaction with the antibodies, making no detectable precipitation in immunoelectrophoresis and no positive reaction in EIA, but showing positive reaction in Western blot and in an inhibition tests. Taking these phenomena and other circumstantial evidences into account, it is concluded that the serum osteopontin has a high molecular fragility, fragmenting into small peptides with few epitopes during incubation time. This fragility, though much lower extent, was also seen in milk osteopontin. Although the exact casual meaning of this fragility was not defined yet, it is conceivable that the fragility of OPN itself has some meaning in its physiological functions. Such possibility is being investigated in our laboratory.

骨桥蛋白（以下称为OPN）是一种CAII D12+IE D1结合蛋白，已研究为分泌的高度酸性哲学蛋白，在各种组织和物种中都具有不同的功能。它首先是从矿化骨基质中分离出来的，并研究为蛋白质重塑矿化组织。由于OPN存在于人乳中，因此我们认为OPN在发育中的婴儿的成骨中起着重要作用。目前的研究旨在隔离和表征人类乳，血清和血细胞中的OPN。我们已经从人乳中分离了骨桥蛋白，制备了对其特异的抗体，并试图建立一个确定血清中骨髓蛋白的三明治型EIA系统。发现血清骨桥蛋白和牛奶骨桥蛋白在与抗体反应时显示出矛盾的现象，在免疫亲子中没有可检测到的沉淀，而在EIA中没有阳性反应，但是在Western Blot和抑制测试中显示出阳性反应。考虑到这些现象和其他环境证据，得出的结论是，血清骨桥蛋白具有高分子脆弱性，在孵育期间碎片碎片成很少的小辣椒。尽管尚未定义这种脆弱性的确切随意含义，但可以想象，OPN本身的脆弱性在其物理功能中具有一定的含义。我们的实验室正在调查这种可能性。