Densitometry of protein isoforms visualised by 2-DE. The densitometry scan demonstrates the purified human cell expressed protein exists in multiple isoforms, which differ according to their level of post-translational modification. The triangle indicates the theoretical MW and pI of the protein.
1D SDS-PAGE of ab83581 before and after treatment with glycosidases to remove oligosaccharides. Lane 1 – MW markers; Lane 2 – ab83581 ; Lane 3 – ab83581 treated with PNGase F to remove potential N-linked glycans; Lane 4 – ab83581 treated with a glycosidase cocktail to remove potential N- and O-linked glycans. Approximately 5 µg of protein was loaded per lane. Drop in MW after treatment with PNGase F indicates presence of N-linked glycans. A further drop in MW after treatment with the glycosidase cocktail indicates the presence of O-linked glycans. Additional bands in lane 3 and lane 4 are glycosidase enzymes.
A sample of ab83581 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. Spot train indicates presence of multiple isoforms of SCF. Spots within the spot train were cut from the gel and identified as SCF by protein mass fingerprinting.