title: Layer-by-Layer Deposition with Polymers Containing Nitrilotriacetate, A Convenient Route to Fabricate Metal- and Protein-Binding Films.
abstract: This paper describes a convenient synthesis of nitrilotriacetate (NTA)-containing polymers and subsequent layer-by-layer adsorption of these polymers on flat surfaces and in membrane pores. The resulting films form NTA-metal-ion complexes and capture 2-3 mmol of metal ions per mL of film. Moreover, these coatings bind multilayers of polyhistidine-tagged proteins through association with NTA-metal-ion complexes. Inclusion of acrylic acid repeat units in NTA-containing copolymers promotes swelling to increase protein binding in films on Au-coated wafers. Adsorption of NTA-containing films in porous nylon membranes gives materials that capture ∼46 mg of His-tagged ubiquitin per mL. However, the binding capacity decreases with the protein molecular weight. Due to the high affinity of NTA for metal ions, the modified membranes show modest leaching of Ni(2+) in binding and rinsing buffers. Adsorption of NTA-containing polymers is a simple method to create metal- and protein-binding films and may, with future enhancement of stability, facilitate development of disposable membranes that rapidly purify tagged proteins.
authors.affiliation: Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.
authors.forename: Salinda
authors.initials: S
authors.lastname: Wijeratne
authors.affiliation: Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.
authors.forename: Weijing
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.
authors.forename: Jinlan
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Ning
authors.affiliation: Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.
authors.forename: Nishanka Dilini
authors.initials: ND
authors.lastname: Ratnayake
authors.affiliation: Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Walker
authors.affiliation: Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.
authors.forename: Merlin L
authors.initials: ML
authors.lastname: Bruening
mesh_terms: D000327:Adsorption; D008670:Metals; D009571:Nitrilotriacetic Acid / Q000737:chemistry*; D011108:Polymers; D011485:Protein Binding; D011506:Proteins
chemical_list: D008670:Metals; D011108:Polymers; D011506:Proteins; D009571:Nitrilotriacetic Acid
keywords: His-tagged protein; NTA; layer-by-layer deposition; membrane adsorbers; polyelectrolytes