64DP与人染色质的结合反应及细胞核内64DP的检测

现有结果表明64 DP(DNA结合蛋白)可能是一种急性期反应蛋白质。正常人每百毫升血清中含有约50mg的64 DP。目前,关于64 DP的生物学功能国内外尚无研究和报道。这方面的研究对阐明肿瘤及其它病理条件下血清64 DP含量增高的机制和意义有可能提供线索。 已知64 DP在体外具有和DNA结合的特性.它在体内的生理作用是否也和DNA有关呢?本实验首先分离纯化了人肝细胞染色质,用同位素标记的64 DP与染色质进行的结合实验及结合抑制实验表明64 DP能特异地与人染色质结合。进一步用~(125)I标记的兔抗64 DP抗体对人染色质作了固相放射免疫测定,结果定性地显示出染色质内可能含有64 DP。用兔抗64 DP抗体作为第一抗体,利用PAP免疫组织化学染色研究了16例正常肝组织切片,发现大多数切片(80％)中部分肝细胞核内有明显64DP显色颗粒。以上诸实验结果均提示细胞核内有64 DP存在,表明64 DP的生物学功能可能与它的DNA结合特性有关。

The Binding of 64DP With Human Chromatin and the Detection of 64DP in Nucleus

64DP is reported to be a kind of acute phase reactive protein.The content of 64DP in serum of normal people is as high as 50mg%. Nevertheless,the biological function of 64DP is still unknown.Research in this regard may provide a clue for clarifying the mechanism and significence of the change of 64DP level under tumor and other pathological conditions.It is known that 64DP can bind DNA in vitro. What we want to know is whether its function in vivo has anything to do with DNA.Chromatin of human hepatocyte was isolated and purified. Binding test and binding inhibitory test using 125I labelled 64DP showed that 64DP can bind specifically with chromatin. Autoradiography of immobilized human chromatin with 125I-antibody against 64DP revealed the existence of 64DP in chromatin. 20 tissue sections of human livers were studied with immunohistochem-istry technique (PAP) .Positive staining for 64DP were shown in some nuclei of hepa-tocytes in most sections(80%) .These results may suggest some relationship between the function of 64DP and its DNA binding character.