title: High-throughput screening and radioligand binding studies reveal monoamine oxidase-B as the primary binding target for d-deprenyl.
abstract: OBJECTIVE
  d-deprenyl is a useful positron emission tomography tracer for visualization of inflammatory processes. Studies with [(11)C]-d-deprenyl showed robust uptake in peripheral painful sites of patients with rheumatoid arthritis or chronic whiplash injury. The mechanism of preferential d-deprenyl uptake is not yet known, but the existence of a specific binding site was proposed. Thus, in the present study, we sought to identify the binding site for d-deprenyl and verify the hypothesis about the possibility of monoamine oxidase enzymes as major targets for this molecule.
  
  
  METHODS
  A high-throughput analysis of d-deprenyl activity towards 165G-protein coupled receptors and 84 enzyme targets was performed. Additionally, binding studies were used to verify the competition of [(3)H]d-deprenyl with ligands specific for targets identified in the high-throughput screen.
  
  
  RESULTS
  Our high-throughput investigation identified monoamine oxidase-B, monoamine oxidase-A and angiotensin converting enzyme as potential targets for d-deprenyl. Further competitive [(3)H]d-deprenyl binding studies with specific inhibitors identified monoamine oxidase-B as the major binding site. No evident high-affinity hits were identified among G-protein coupled receptors.
  
  
  CONCLUSIONS
  Our study was the first to utilize a high-throughput screening approach to identify putative d-deprenyl targets. It verified 249 candidate proteins and confirmed the role of monoamine oxidase - B in d-deprenyl binding. Our results add knowledge about the possible mechanism of d-deprenyl binding, which might aid in explaining the increased uptake of this compound in peripheral inflammation. Monoamine oxidase-B will be further investigated in future studies utilizing human inflamed synovium.
authors.affiliation: Uppsala University, Department of Pharmaceutical Biosciences, SE 751 24 Uppsala, Sweden. Electronic address: anna.lesniak@farmbio.uu.se.
authors.forename: Anna
authors.initials: A
authors.lastname: Lesniak
authors.affiliation: Uppsala University Hospital, Department of Surgical Sciences, Anaesthesiology and Intensive Care, SE 751 85 Uppsala, Sweden.
authors.forename: Mikko
authors.initials: M
authors.lastname: Aarnio
authors.affiliation: Uppsala University, Department of Pharmaceutical Biosciences, SE 751 24 Uppsala, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Jonsson
authors.affiliation: Uppsala University, Department of Chemistry, SE 751 23 Uppsala, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Norberg
authors.affiliation: Uppsala University, Department of Pharmaceutical Biosciences, SE 751 24 Uppsala, Sweden.
authors.forename: Fred
authors.initials: F
authors.lastname: Nyberg
authors.affiliation: Uppsala University Hospital, Department of Surgical Sciences, Anaesthesiology and Intensive Care, SE 751 85 Uppsala, Sweden.
authors.forename: Torsten
authors.initials: T
authors.lastname: Gordh
mesh_terms: D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive / Q000187:drug effects; D057166:High-Throughput Screening Assays / Q000379:methods; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D008995:Monoamine Oxidase / Q000187:drug effects* / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000378:metabolism* / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism; D011869:Radioligand Assay / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D012642:Selegiline / Q000378:metabolism* / Q000494:pharmacology; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D008996:Monoamine Oxidase Inhibitors; D043562:Receptors, G-Protein-Coupled; D012642:Selegiline; D008995:Monoamine Oxidase; D007703:Peptidyl-Dipeptidase A
keywords: Binding site; High-throughput screening; d-deprenyl