Lane 1 – MW markers; Lane 2 – ab83931; Lane 3 – ab83931 treated with PNGase F to remove potential N-linked glycans; Lane 4 – ab83931 treated with a glycosidase cocktail to remove potential N- and O-linked glycans. 3 μg of protein was loaded per lane. Gels were stained with Coomassie G250. Drop in MW after treatment with PNGase F indicates the presence of N-linked glycans. A subsequent drop in MW after treatment with a glycosidase cocktail indicates O-linked glycans are also present. Additional high MW bands in lane 4 are glycosidase enzymes.
A sample of ab83931 without carrier protein was reduced and alkylated. 40 μg of protein was loaded, focused on a 3-10 IPG strip then run on a 4-20% Tris-HCl 2D gel. Spot train (Deep Purple™ stained) indicates presence of multiple glycoforms of BAFF Receptor - Fc Chimera. Spots within the spot train were cut from the gel and identified by protein mass fingerprinting as BAFF Receptor - Fc Chimera.
Post-translational modifications result in protein heterogeneity. The densitometry scan demonstrates the purified human cell expressed protein exists in multiple glycoforms, which differ according to their level of post-translational modification.