Isolation of Fucosyl Glycoproteins from Human Erythrocyte Membranes by Affinity Chromatography Using Aleuria aurantia Lectinl

Abstract

Fucosyl glycoproteins were fractionated from a sialoglycoprotein preparation of human erythrocyte membrane by using Aleuria aurantia lectin (AAL) coupled to Sepharose 4B. The affinity eluates were characterized as having high fucose content and significant H activity as measured in terms of N-acetylgalactosamine (GaINAc) incorporation with A₁-enzyme and hemagglutination inhibition assay with anti-H sera, and the unadsorbed fractions contained low levels of fucose and were devoid of apparent H activity. Neuraminidase treatment of the material improved the recovery of the affinity eluate. Thus, 66% of the applied asialoglycoprotein was recovered in the eluate, though only 10% of the untreated material was bound and eluted. Moreover, a fucose-rich and H-active fraction was obtained through the affinity chromatography of the previously unbound fraction after neuraminidase treatment. In sodium dodecyl sulfate-gel electrophoresis, the main component of both the unadsorbed and eluted fraction was revealed to be PAS-1 glycoprotein.
These results indicate that AAL-Sepharose was effective for isolating fucose-containing compounds from the membrane glycoprotein especially after neuraminidase treatment. The reasons for the appearance of H activity in the affinity eluates are discussed.