title: Binding between proteins and cationic spherical polyelectrolyte brushes: effect of pH, ionic strength, and stoichiometry.
abstract: Cationic spherical polyelectrolyte brushes (SPBs) were synthesized by photoemulsion polymerization, consisting of a polystyrene core with a diameter around 80 nm and a poly(2-aminoethylmethacrylate hydrochloride) (PAEMH) shell with a thickness from 10 to 50 nm densely grafted on the core surface. The binding of various proteins onto SPBs was observed by turbidimetric titration, dynamic light scattering (DLS), zeta potential, and isothermal titration calorimetry (ITC). The binding, aggregation, and releasing of proteins by SPB can be tuned by modulating pH. The pH regions of binding for bovine serum albumin (BSA), β-lactoglobulin (BLG), and papain onto SPBs are markedly different and tunable by ionic strength and stoichiometry between protein and SPB. Binding energetics, affinity, and amount of various proteins onto cationic SPBs were determined by ITC. These findings lay the foundation for SPB applications in the protein purification and selective immobilization of different proteins, enzymes, and antibodies.
authors: State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, People's Republic of China.
authors: Siyi
authors: S
authors: Wang
authors: Kaimin
authors: K
authors: Chen
authors: Li
authors: L
authors: Li
authors: Xuhong
authors: X
authors: Guo
mesh_terms: D000327:Adsorption; D000818:Animals; D002151:Calorimetry; D002417:Cattle; D006863:Hydrogen-Ion Concentration; D007782:Lactoglobulins / Q000737:chemistry; D008689:Methacrylates / Q000737:chemistry; D009994:Osmolar Concentration; D011073:Polyamines / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D000071228:Polyelectrolytes; D011137:Polystyrenes / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D007782:Lactoglobulins; D008689:Methacrylates; D011073:Polyamines; D000071228:Polyelectrolytes; D011137:Polystyrenes; D011506:Proteins; D012710:Serum Albumin, Bovine; C072703:2-aminoethylmethacrylate