Protein adsorption on histidyl-aminohexyl-Sepharose 4B II. Application to the negative one-step affinity purification of human beta 2-microglobulin and Immunoglobulin G

The adsorption of two human proteins, beta -microglobulin and Immunoglobuli n G, from uremic patient's blood ultrafiltrate and plasma, respectively, wa s investigated on the histidyl-aminohexyl-Sepharose 4B adsorbent. Both targ et proteins could be adsorbed on the gel through a low affinity for immobil ized histidine ligand. However, a fine adjustment of the operating conditio ns (ionic strength, buffer, pH) prevented their adsorption and thus allowed their "negative affinity" purification (purity estimated by silver nitrate SDS-PAGE) by the removal of the contaminating proteins. This simple and ef ficient method provides purification under gentle chromatographic condition s and a further characterization of both molecules. (C) 2001 Elsevier Scien ce B.V. All rights reserved.