Protein adsorption on histidyl-aminohexyl-Sepharose 4B: I. Study of the mechanistic aspects of adsorption for the separation of human serum albumin from its non-enzymatic glycated isoforms (advanced glycosylated end products)

Abstract

The characteristics of albumin adsorption on histidyl-aminohexyl-Sepharose 4B were investigated. In particular, the adsorption capacity of the gel was studied as a function of conductivity and pH of the running buffer. The adsorption was maximum at low salt concentration around neutral pH, involving electrostatic and hydrophobic interactions. Kinetic aspects were also investigated. Dissociation constant ( K D) and maximum capacity ( Q x ) were, respectively, estimated to be 4.5×10 −5 M (medium affinity) and 93.3 mg (high capacity) of human serum albumin per ml of adsorbent. According to these preliminary results, separation of HSA and its non-enzymatically glycated isoforms (conventionally named advanced glycated end products: AGEs) was achieved. Chromatographic potential of this separation tool is discussed.