Tsuiji H, Hong J C, Kim Y S, Ikehara Y, Narimatsu H, Irimura T
Graduate School of Pharmaceutical Sciences, University of Tokyo, Japan.
Biochem Biophys Res Commun. 1998 Dec 18;253(2):374-81. doi: 10.1006/bbrc.1998.9726.
Monoclonal antibody (mAb) 91.9H was previously prepared against partially purified human colonic sulfomucins. The epitope was detected in normal colonic mucosa and primary and metastatic colorectal carcinoma in decreasing order of magnitude. In the present study, this antibody was shown to recognize sulfo-Le(a) structure, HSO3-3Gal beta 1-3(Fuc alpha 1-4)GlcNAc. Interactions between mAb 91.9H and synthetic oligosaccharides conjugated with biotinylated polyacrylamide carrier were examined by a biosensor based on surface plasmon resonance and by enzyme-linked immunosorbent assays. This mAb bound to sulfo-Lea but not to sulfo-LeX, Le(a), LeX, sialyl-Le(a), or sialyl-LeX. Sulfo-Le(a) oligosaccharides decreased its binding affinity with mAb 91.9H after periodate oxidation of its fucose residue. Immunohistochemical study showed a strong binding of mAb 91.9H to goblet cells in human colonic epithelia of Lewis-positive individuals but a trace binding in Lewis-negative individuals, confirming the specificity of this antibody toward structures containing a fucosylated type 1 backbone.
单克隆抗体（mAb）91.9H先前是针对部分纯化的人结肠硫酸黏蛋白制备的。该表位在正常结肠黏膜以及原发性和转移性结直肠癌中均有检测到，其含量呈递减顺序。在本研究中，该抗体被证明可识别硫酸化Le（a）结构，即HSO3-3Galβ1-3（Fucα1-4）GlcNAc。通过基于表面等离子体共振的生物传感器和酶联免疫吸附测定法，研究了mAb 91.9H与结合有生物素化聚丙烯酰胺载体的合成寡糖之间的相互作用。该单克隆抗体与硫酸化Le（a）结合，但不与硫酸化Le（X）、Le（a）、Le（X）、唾液酸化Le（a）或唾液酸化Le（X）结合。硫酸化Le（a）寡糖在其岩藻糖残基经高碘酸盐氧化后，降低了其与mAb 91.9H的结合亲和力。免疫组织化学研究表明，mAb 91.9H与Lewis阳性个体的人结肠上皮中的杯状细胞有强烈结合，但与Lewis阴性个体仅有微量结合，证实了该抗体对含有岩藻糖基化1型主链结构的特异性。
