Protein Purification with Polymeric Affinity Membranes Containing Functionalized Poly(acid) Brushes

Abstract

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 less than 10 min, and the protein purity is comparable to that achieved with commercial affinity columns. Thus, porous nylon membranes containing functionalized poly(MES) brushes are attractive candidates for rapid, high-capacity purification of His-tagged proteins from cell extracts.

pH‐Responsive Nanoporous Silica Colloidal Membranes

“…For example, porous nylon membranes modified with poly(acid) brushes for rapid protein purification via ion-exchange and metal-ion affinity interactions have been recently reported. [21] Nanoporous membranes have been prepared using alumina, [22] track-etched polycarbonate, [23] polymers, [24] zeolites, [25] soft lithographic techniques, [26] ion beam etching of silicon nitride and oxide, [27] and by embedding carbon nanotubes. [28] Our strategy is based on utilizing silica colloidal crystals as an ordered porous material that possesses high molecular flux and easily controllable nanopore size.…”

Polymer Brushes with Precise Architectures for Molecular Biorecognition

“…Due to this issue, several reports describe the use of this metal ion for oligohistidine-protein purification. Porous membranes [103,104] or magnetic nanoparticles [105] were functionalized with NTA-Ni(II) complexes which have been grafted onto polymer brushes. These functional polymeric supports were able to purify oligohistidine-tagged proteins with a purity > 99 % directly from cell extracts or a mixture of proteins.…”

Poly(styrene–divinylbenzene) beads surface functionalized with di-block polymer grafting and multi-modal ligand attachment: performance of reversibly immobilized lipase in ester synthesis

“…Epoxy functional polymer brushes such as poly(glycidyl methacrylate) can be created on an insoluble polymeric support via surface-initiated atom transfer radical polymerization methodology [21]. In this hybrid polymer system, ligand attached polymer brush layers will effectively involve in high capacity-enzyme binding and could increase the enzymatic reaction rates [21][22][23].…”