title: Assembly and characterization of biofunctional neurotransmitter-immobilized surfaces for interaction with postsynaptic membrane receptors.
abstract: Herein, we report progress toward the development of bioactive surfaces based on gamma-aminobutyric acid (GABA), a major neurotransmitter in the nervous system. Whereas immobilization techniques have focused largely on antibodies, enzymes, and receptors, to our knowledge, this is the first report of a prototype neurotransmitter-immobilized surface. Biosurfaces were assembled onto either mica or glass using passive adsorption of avidin and subsequent attachment of a derivatized form of GABA via a biotin-avidin affinity bond. Surface characterization of these prepared bimolecular surfaces was determined using atomic force microscopy in tapping mode. The data reveal that passive adsorption of avidin is uniformly dispersed and cluster densities can be controlled through the concentration of the avidin incubation solution. GABA tethered via biotin to these avidin surfaces displayed a unique surface topology; in addition, histograms of surface heights suggest two different types of molecular cluster populations. Functional assays were performed to test the biological activity of the synthesized GABA. Anti-GABA antibody directed to these bimolecular surfaces result in morphological topologies and histograms that indicate antibody-antigen binding. However, nonspecific anti-immunoglobulin G antibodies directed to these surfaces show low binding affinity. Taken together, the data support the idea that the synthesized surfaces are biofunctional.
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Uroosa
authors.initials: U
authors.lastname: Saifuddin
authors.forename: Tania Q
authors.initials: TQ
authors.lastname: Vu
authors.forename: Miroslav
authors.initials: M
authors.lastname: Rezac
authors.forename: Haohua
authors.initials: H
authors.lastname: Qian
authors.forename: David R
authors.initials: DR
authors.lastname: Pepperberg
authors.forename: Tejal A
authors.initials: TA
authors.lastname: Desai
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D001360:Avidin / Q000737:chemistry; D019921:Biotinylation; D005898:Glass; D051379:Mice; D018625:Microscopy, Atomic Force; D018079:Receptors, GABA / Q000378:metabolism*; D013499:Surface Properties; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism
chemical_list: D000538:Aluminum Silicates; D000911:Antibodies, Monoclonal; D018079:Receptors, GABA; D001360:Avidin; D005680:gamma-Aminobutyric Acid; C011934:mica