title: Dopaminergic receptor-ligand binding assays based on molecularly imprinted polymers on quartz crystal microbalance sensors.
abstract: Molecularly imprinted polymers (MIPs) have been successfully applied as selective materials for assessing the binding activity of agonist and antagonist of dopamine D1 receptor (D1R) by using quartz crystal microbalance (QCM). In this study, D1R derived from rat hypothalamus was used as a template and thus self-organized on stamps. Those were pressed into an oligomer film consisting of acrylic acid: N-vinylpyrrolidone: N,N'-(1,2-dihydroxyethylene) bis-acrylamide in a ratio of 2:3:12 spin coated onto a dual electrode QCM. Such we obtained one D1R-MIP-QCM electrode, whereas the other electrode carried the non-imprinted control polymer (NIP) that had remained untreated. Successful imprinting of D1R was confirmed by AFM. The polymer can re-incorporate D1R leading to frequency responses of 100-1200Hz in a concentration range of 5.9-47.2µM. In a further step such frequency changes proved inherently useful for examining the binding properties of test ligands to D1R. The resulting mass-sensitive measurements revealed Kd of dopamine∙HCl, haloperidol, and (+)-SCH23390 at 0.874, 25.6, and 0.004nM, respectively. These results correlate well with the values determined in radio ligand binding assays. Our experiments revealed that D1R-MIP sensors are useful for estimating the strength of ligand binding to the active single site. Therefore, we have developed a biomimetic surface imprinting strategy for QCM studies of D1R-ligand binding and presented a new method to ligand binding assay for D1R.
authors.affiliation: Molecular Recognition Materials Research Unit, Drug Delivery System Excellence Center, and NANOTEC Center of Excellence, Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hatyai, Songkhla 90112, Thailand; University of Vienna, Department of Analytical Chemistry, Faculty of Chemistry, Währinger Straße 38, A-1090 Vienna, Austria.
authors.forename: Wanpen
authors.initials: W
authors.lastname: Naklua
authors.affiliation: Molecular Recognition Materials Research Unit, Drug Delivery System Excellence Center, and NANOTEC Center of Excellence, Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hatyai, Songkhla 90112, Thailand.
authors.forename: Roongnapa
authors.initials: R
authors.lastname: Suedee
authors.affiliation: University of Vienna, Department of Analytical Chemistry, Faculty of Chemistry, Währinger Straße 38, A-1090 Vienna, Austria. Electronic address: Peter.Lieberzeit@univie.ac.at.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Lieberzeit
mesh_terms: D000179:Acrylates / Q000737:chemistry; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods; D005260:Female; D008024:Ligands; D008297:Male; D054802:Molecular Imprinting / Q000379:methods; D011485:Protein Binding; D011760:Pyrrolidinones / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1 / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000179:Acrylates; D008024:Ligands; D011760:Pyrrolidinones; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; C042670:N-vinyl-2-pyrrolidinone; C036658:acrylic acid
keywords: Dopamine receptor; Ligand binding assay; Molecularly imprinted polymer; Quartz crystal microbalance