Biomacromolecules 2010, 11, 1019–1026
1019
Protein Purification with Polymeric Affinity Membranes Containing Functionalized Poly(acid) Brushes Parul Jain, Mukesh Kumar Vyas, James H. Geiger, Gregory L. Baker,* and Merlin L. Bruening* Department of Chemistry Michigan State University East Lansing, Michigan 48824 Received December 28, 2009; Revised Manuscript Received February 15, 2010
Porous nylon membranes modified with poly(acid) brushes and their derivatives can rapidly purify proteins via ion-exchange and metal-ion affinity interactions. Membranes containing poly(2-(methacryloyloxy)ethyl succinate) (poly(MES)) brushes bind 118 ( 8 mg of lysozyme per cm3 of membrane and facilitate purification of lysozyme from chicken egg white. Moreover, functionalization of the poly(MES) brushes with nitrilotriacetate (NTA)-Ni2+ complexes yields membranes that bind poly(histidine)-tagged (His-tagged) ubiquitin with a capacity of 85 ( 2 mg of protein per cm3 of membrane. Most importantly, the membranes modified with poly(MES)-NTA-Ni2+ allow isolation of His-tagged cellular retinaldehyde-binding protein directly from a cell extract in
