Rapid detection of the main human plasma glycoproteins by two-dimensional polyacrylamide gel electrophoresis lectin affinoblotting

Glycoprotein modifications in the glycan moiety can occur in diseases such as cancers, inflammatory processes and alcoholism. We combined high-resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) with lectin affinoblotting in order to establish the normal human plasma glycoprotein map. Human plasma proteins were separated by mini 2-D PAGE (7 x 9 cm), transferred onto polyvinylidene difluoride membranes and incubated with biotinylated lectins. We focused our study on lectins binding sialic acid and galactose residues. Known plasma glycoproteins such as alpha 1-antitrypsin, alpha 1-antichymotrypsin, alpha 2-HS glycoprotein, alpha 1-acid glycoprotein, haptoglobin beta-chain and transferrin were easily detected in ng amounts. This protocol was adequate to establish a normal plasma glycoprotein map and will allow the study of glycoproteins in diseases.