Nolli M L, Corti A, Soffientini A, Cassani G
Thromb Haemost. 1986 Oct 21;56(2):214-8.
An anti-urokinase monoclonal antibody 5B4 (MAB 5B4) was obtained by fusing the murine myeloma cell line X63-Ag8.653 with the spleen cells from a female BALB/c mouse immunized with high-molecular-weight urokinase (HMW-uPA). MAB 5B4 is an IgG1 that binds selectively to the single-chain form of uPA (sc-uPA), to HMW-uPA and to the 17,000 Mr aminoterminal fragment of the A-chain (ATF) but not to the low-molecular-weight urokinase (LMW-uPA) nor to the reduced form of HMW-uPA. This strongly suggests that MAB 5B4 recognizes a conformational determinant on the A-chain. The antibody has an affinity constant for uPA-Sepharose of 1.42 X 10(7) M-1, calculated from equilibrium binding data, and can be used for one step purification of HMW-uPA by immunoaffinity chromatography. MAB 5B4 and the previously obtained antibody 105IF10 recognize the A-chain: the epitopes, however, are distinct as shown by double-antibody-sandwich enzyme immunoassay. Finally MAB 5B4 inhibits the binding of ATF to the uPA receptor of different human cells, whereas 105IF10 does not. Thus this antibody represents a potentially, useful tool for the study of uPA receptor physiology.
通过将小鼠骨髓瘤细胞系X63-Ag8.653与用高分子量尿激酶（HMW-uPA）免疫的雌性BALB/c小鼠的脾细胞融合，获得了一种抗尿激酶单克隆抗体5B4（MAB 5B4）。MAB 5B4是一种IgG1，它选择性地结合单链形式的uPA（sc-uPA）、HMW-uPA和A链的17,000 Mr氨基末端片段（ATF），但不结合低分子量尿激酶（LMW-uPA）也不结合HMW-uPA的还原形式。这强烈表明MAB 5B4识别A链上的一个构象决定簇。根据平衡结合数据计算，该抗体对uPA-琼脂糖的亲和常数为1.42×10⁷ M⁻¹，可用于通过免疫亲和色谱一步纯化HMW-uPA。MAB 5B4和先前获得的抗体105IF10识别A链：然而，如双抗体夹心酶免疫测定所示，表位是不同的。最后，MAB 5B4抑制ATF与不同人类细胞的uPA受体的结合，而105IF10则不抑制。因此，这种抗体是研究uPA受体生理学的一种潜在有用工具。
