A simplified purification procedure of alpha-lactalbumin from milk using Ca(2+)-dependent adsorption in hydrophobic expanded bed chromatography.

The technique of expanded bed adsorption is originally designed for a direct recovery of proteins from fermentor feedstocks. In this article we describe the use of expanded bed adsorption for the recovery of alpha-lactalbumins from defatted milk using the hydrophobic Streamline Phenyl gel. alpha-Lactalbumins are Ca(2+)-binding proteins. Upon Ca2+ removal, they undergo a significant conformation change rendering them more hydrophobic. Based on this unique property we develop a protocol for fast and efficient purification of alpha-lactalbumin from milk. The use of this technique results in a reduction of the number of chromatographic purification steps.