BioScience Trends. 2010;4(6):308-311.
Preparation of asialo-agalacto-glycophorin A for screening of anti-Tn antibodies.
Koizumi T, Matsumoto-Takasaki A, Nakada H, Nakata M, Fujita-Yamaguchi Y
Oncogenic antigens such as Tn-antigen (GalNAcα-Ser/Thr) are involved in metastatic processes and are associated with a poor prognosis, thus representing excellent targets for cancer intervention. Available anti-Tn antibodies which can be applied for therapeutics or diagonostics are severely limited mostly because the Tn-antigen epitope by itself is too small to be antigenic in addition to the fact that many carbohydrates are self-antigens. To characterize anti-Tn monoclonal antibodies as well as to perform panning and screening for isolation of anti-Tn single chain variable fragments from phage-display libraries, a large quantity of inexpensive Tn-antigens are needed. In this study, thus, glycophorin A which is a highly glycosylated sialoglycoprotein with approximately 12 O-glycans was sequentially treated with sialidase and β-galactosidase to remove sialic acid and galactose residues. The resulted product was shown to be an asialo-agalacto-glycophorin A which is reactive to an anti-Tn-antigen antibody. The simple preparation procedures described here would greatly help production and characterization of potentially valuable anti-Tn-antigen antibodies, which can be readily developed for cancer therapeutics and diagnostics.