Purification of the glycoprotein allergen Ag7 from mugwort pollen by concanavalin A affinity chromatography

Elution of tightly bound solutes from concanavalin A Sepharose

“…Some authors have reported that NaCl in the elution buffer promotes more complete desorption of the glycoprotein of interest [16][17][18][19][20]. Many have included NaCl in both equilibration and desorption buffers at concentrations as high as 1.0 M [10,13,21,22]. Baumstark [23] reported that Con A Sepharose chromatography using 1.0 M NaCl in the elution buffer results in earlier elution for most of the 14 serum proteins examined, particularly ceruleoplasmin and α 2macroglobulin.…”

“…A review of the literature reveals that most bound solutes are relatively easily desorbed from Con A Sepharose with modest concentrations of competitive eluents (usually 50-200 mM methyl-α-D-mannopyranoside, or methyl-α-Dglucopyranoside); however, some glycoproteins bind to Con A Sepharose so tightly that common elution techniques are ineffective [1]. Many authors report lower than expected yields [2][3][4][5][6][7][8][9][10] or solutes that are refractory to increasing sugar concentrations [11][12][13]. Undesorbed protein not only reduces the yield of the target protein, but also the column capacity [1].…”