Lane 1 – MW markers; Lane 2 – ab83922; Lane 3 – ab83922 treated with PNGase F to remove potential N-linked glycans; Lane 4 – ab83922 treated with a glycosidase cocktail to remove potential N- and O-linked glycans. Approximately 5 µg of protein was loaded per lane; Gel was stained using Coomassie. Drop in MW after treatment with PNGase F indicates the presence of N-linked glycans. Additional bands in lane 3 and lane 4 are glycosidase enzymes.
A sample of ab83922 without carrier protein was reduced and alkylated and focused on a 3-10 IPG strip then run on a 4-20% Tris-HCl 2D gel. Approximately 40 µg of protein was loaded; Gel was stained using Deep Purple™. The spot train indicates the presence of multiple glycoforms of ab83922. Spots within the spot train were cut from the gel and identified as Activin Receptor Type IA (Fc Chimera) by protein mass fingerprinting.
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. The triangle indicates theoretical pI and MW of the protein.