Zeolites as new chromatographic carriers for proteins—easy recovery of proteins adsorbed on zeolites by polyethylene glycol

Zeolites are able to adsorb proteins on their surface and might be suitable as a new type of chromatographic carrier material for proteins and for their conjugates (Matsui et al., Chem. Eur. J. 7 (2001) 1555–1560). Interestingly, maximum adsorption was observed at the isoelectric point (p I) of each protein. The current study was performed to investigate the desorption of proteins from the zeolites at p I. Proteins adsorbed to zeolites could be desorbed at p I by polyethylene glycol (PEG), but not by conventional eluents. The eluted proteins still retained their activities. The zeolite Na-BEA was an especially good composite for desorption by PEG. Using this method for the adsorption and desorption of proteins at p I, we succeeded in separating various proteins. The application of zeolites to biochemistry and biotechnology is also discussed.