Site-oriented His-tag proteins on solid substrates: Optimizing biofunctional surfaces

STRAGLIOTTO, MA. FERNANDA; HERRERA, ELISA G.; VALENTI, LAURA E.; GIACOMELLI, CARLA E.

San Diego, California

Congreso; 23rd ACS Nacional Meeting; 2012

American Chemical Society

Site-oriented His-tag proteins on solid substrates: Optimizing biofunctional surfaces   Maria Fernanda Stragliotto, Elisa G. Herrera, Laura E. Valenti, Carla E. Giacomelli. INFIQC. Departamento de Fisicoquímica. Facultad de Ciencias Quِímicas. Universidad Nacional de Córdoba   The purpose of this presentation is to discuss experimental results on site-oriented chemical adsorption, induced by modifying the substrate with Ni(II) in combination with recombinant His-tag proteins (antigens and enzymes) used to design novel biofunctional surfaces. To this end, the presentation covers from the expression, purification and characterization of the recombinant proteins up to the surface biorecognition capabilities. The substrate modification is based on the formation of amino terminated SAMs either on gold or silica to anchor nitrilotriacetic acid (NTA) that strongly interacts with Ni(II). His-tagged proteins remove water molecules from NTA-Ni chelate leading to a stable octahedral complex on the substrate. However, physical protein adsorption also takes place which is mostly desorbed upon dilution at high degree of surface coverage. The biofunctional surface shows a good biological response as monitored by direct electrochemical methods. The proposed strategy provides a simple way to prepare reusable biofunctional surfaces on different substrates.