Protein adsorption on histidyl-aminohexyl-Sepharose 4B. II. Application to the negative one-step affinity purification of human beta2-microglobulin and immunoglobulin G.

The adsorption of two human proteins, beta2-microglobulin and Immunoglobulin G, from uremic patient's blood ultrafiltrate and plasma, respectively, was investigated on the histidyl-aminohexyl-Sepharose 4B adsorbent. Both target proteins could be adsorbed on the gel through a low affinity for immobilized histidine ligand. However, a fine adjustment of the operating conditions (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 efficient method provides purification under gentle chromatographic conditions and a further characterization of both molecules.