Controlling the Covalent and Noncovalent Adsorption of Proteins on Polymeric Surfaces in Auqeous Liquids

水溶液中蛋白质在聚合物表面共价及非共价吸附的控制

The adsorption and covalent immobilization of human immunoglobulin(HIgG),lysozyme,α-chymotrypsin,and myoglobin have been compared using different experimental techniques:ellipsometry(ELM),X-ray photoelectron spectroscopy(XPS),optical fluorescence and atomic force microscopy(AFM).All measurements of the protein-surface interactions were performed with identically prepared Polysterine maleic acid(PSMA),Poly(methyl methacrylate)(PMMA),and Poly(tert-butyl methacrylate)P(tBuMA)polymeric substrates.Functionalized via UV exposure PMMA and P(tBuMA)films were utilized to couple proteins via an N-hydroxysuccinimide(NHS)intermediate.The covalent binding was evaluated by XPS analysis.The optical techniques showed a good correlation in terms of variable-dense protein layer formation(surface coverage range between 4-23 ng/mm2)of adsorbed and covalently bound proteins.The covalent immobilization resulted in stable monolayer formation confirmed by ELM and AFM imaging,in contrast to rigorous interaction with surfaces of adsorbed proteins often resulted in multilayer formation.The results demonstrate that the covalent protein immobilization is an effective and robust way to achieve dense and stable protein monolayer formation.