da Cruz L A, Cruz T F, Moscarello M A
Department of Biochemistry, Hospital for Sick Children, Toronto, Ontario, Canada.
Cell Adhes Commun. 1993 May;1(1):9-20. doi: 10.3109/15419069309095678.
We have isolated and characterized an antigen from normal human brain called p80, so called because it migrated with an M(r) of 80 kDa on SDS PAGE. The M(r) of 80 kDa consists of a protein of about 55-60 kDa and carbohydrate (20-25 kDa). The carbohydrate is almost entirely of the N-linked type, although a small amount of O-linked carbohydrate was detected. Cross-reactivity with monoclonal antibodies A3D8 and A1G3 showed that p80 could therefore be considered an isoform of the CD44 adhesion molecules. In addition, specific binding to hyaluronate which was not competed for by proteoglycan demonstrated that it involved different sites than the proteoglycan binding sites. We also observed that fucoidan and dextran sulphate increased the binding by 200-250% while chondroitin sulphate C also increased the binding but to a lesser extent. Heparin, heparan sulphate and chondroitin sulphates A and B did not have such an effect. The binding of p80 to hyaluronate was pH dependent with a maximum at pH 6.4. We concluded that p80 was an astrocyte specific adhesion molecule.
我们从正常人脑中分离并鉴定了一种名为p80的抗原，之所以这样命名是因为它在SDS-PAGE上的迁移率为80 kDa。80 kDa的迁移率由一种约55 - 60 kDa的蛋白质和碳水化合物（20 - 25 kDa）组成。碳水化合物几乎全部为N-连接型，不过也检测到少量O-连接碳水化合物。与单克隆抗体A3D8和A1G3的交叉反应表明，p80因此可被视为CD44黏附分子的一种异构体。此外，与蛋白聚糖不存在竞争关系的与透明质酸的特异性结合表明，它涉及的位点与蛋白聚糖结合位点不同。我们还观察到，岩藻依聚糖和硫酸葡聚糖使结合增加了200 - 250%，而硫酸软骨素C也增加了结合，但程度较小。肝素、硫酸乙酰肝素以及硫酸软骨素A和B则没有这种作用。p80与透明质酸的结合呈pH依赖性，在pH 6.4时达到最大值。我们得出结论，p80是一种星形胶质细胞特异性黏附分子。
