Murray B A, Yee L D, Loomis W F
J Supramol Struct Cell Biochem. 1981;17(3):197-211. doi: 10.1002/jsscb.380170302.
We have prepared antisera in rabbits to the "contact sites A" glycoprotein (gp80) purified from Dictyostelium discoideum. IgG isolated these antisera reacts with a number of different proteins in D discoideum lysates, as analyzed by immune precipitation and by antibody staining of gel electropherograms transferred to nitrocellulose. blocking experiments indicate that this cross-reactivity reflects the presence of common antigeneic determinants on gp80 and other cellular proteins, rather than the presence of extraneous antibodies in the antisera. The spectrum of reactive proteins is different at different stages of development. In particular, gp80 itself is synthesized only for a restricted period during the cell aggregation phase. The protein persists throughout development and can be detected in spores. Anti-gp80 Fab fragments bind to the surface of developing D discoideum cells and specifically block their developmentally regulated adhesion. After absorption with vegetative cells, the IgG stains only gp80 and (to a lesser extent) one other band in lysates of aggregation-competent cells. The absorbed antibodies also can block adhesion. Several proteins that appear late in development also are stained by the absorbed IgG.
我们已在兔体内制备了针对从盘基网柄菌中纯化出的“接触位点A”糖蛋白（gp80）的抗血清。通过免疫沉淀以及对转移至硝酸纤维素膜上的凝胶电泳图谱进行抗体染色分析发现，从这些抗血清中分离出的IgG能与盘基网柄菌裂解物中的多种不同蛋白质发生反应。阻断实验表明，这种交叉反应反映了gp80和其他细胞蛋白上存在共同的抗原决定簇，而非抗血清中存在外来抗体。在发育的不同阶段，反应性蛋白的谱不同。特别地，gp80自身仅在细胞聚集阶段的一段有限时期内合成。该蛋白在整个发育过程中持续存在，并且在孢子中可被检测到。抗gp80 Fab片段结合到正在发育的盘基网柄菌细胞表面，并特异性阻断其发育调控的黏附。用营养细胞吸收后，IgG仅对具有聚集能力的细胞裂解物中的gp80和（程度较轻地）另一条带进行染色。吸收后的抗体也能阻断黏附。在发育后期出现的几种蛋白质也被吸收后的IgG染色。
