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.

Neurotransmitter analog tethered to a silicon platform for neuro‐bioMEMS applications

“…This work extends a previous study involving passive avidin adsorption and subsequent immobilization of a form of biotinylated GABA (Saifuddin et al, 2003). To our knowledge, the present study is the first to report surfacetethering of a neurotransmitter analog using covalent and avidin-biotin immobilization techniques.…”

2-Aminoethyl Methylphosphonate, a Potent and Rapidly Acting Antagonist of GABAA-ρ1 Receptors

“…The second objective was to determine whether substitution at any of the carbon atoms of 2-AEMP preserves significant activity of the compound at GABA A -1 receptors. This question is of interest for potential neurobiology applications in which a chainderivatized form of this type of GABA analog could be tethered to an anchoring surface via, for instance, streptavidin (Saifuddin et al, 2003;Nehilla et al, 2004;Vu et al, 2005), to a nanoparticle (Gussin et al, 2006), or to the receptor itself (Volgraf et al, 2006;Numano et al, 2009). 2-AEMP derivatives are relatively easy to prepare, and the key building blocks, phosphonic acids and 2-aminoalcohols, are readily available.…”

Modulating Neuronal Responses by Controlled Integration of Acetylcholine‐like Functionalities in Biomimetic Polymers

“…[3] One way to achieve biomimicry is to integrate biomolecules into polymers. Surface-tethered neurotransmitters [4,5] can activate the corresponding cellular receptors, and neurotransmitters directly integrated into a biomimetic polymer can induce specific neuronal responses. [6] To further explore the potential of neurotransmitter-based biomaterials, we set out to modulate neuronal responses by controlling the composition of acetylcholine-like functionalities (ALFs) in a series of novel biomimetic polymers.…”