title: Discovery of novel cyclophilin A ligands using an H/D exchange- and mass spectrometry-based strategy.
abstract: Cyclophilin A (CypA) is an overexpressed protein in lung cancer tumors and as a result is a potential therapeutic and diagnostic target. Described here is use of an H/D exchange- and a matrix assisted laser desorption/ionization (MALDI) mass spectrometry-based assay, termed single-point SUPREX (Stability of Unpurified Proteins from Rates of H/D Exchange), to screen 2 chemical libraries, including the 1280-compound LOPAC library and the 9600-compound DIVERSet library, for binding to CypA. This work represents the first application of single-point SUPREX using a pooled ligand approach, which is demonstrated here to yield screening rates as fast as 6 s/ligand. The false-positive and false-negative rates determined in the current work using a set of control samples were 0% and 9%, respectively. A false-positive rate of 20% was found in screening the actual libraries. Eight novel ligands to CypA were discovered, including 2-(α-naphthoyl)ethyltrimethyl-ammonium iodide, (E)-3-(4-t-Butylphenylsulfonyl)-2-propenenitrile, 3-(N-benzyl-N-isopropyl)amino-1-(naphthalen-2-yl)propan-1-one, cis-diammineplatinum (II) chloride, 1-(3,5-dichlorophenyl)-1H-pyrrole-2,5-dione, N-(3-chloro-1, 4-dioxo-1,4-dihydro-2-naphthalenyl)-N-cyclohexylacetamide, 1-[2-(3,4-dimethoxyphenyl)ethyl]-1H-pyrrole-2,5-dione, and 4-(2-methoxy-4-nitrophenyl)-1-methyl-10-oxa-4-azatricyclo[5.2.1.0~2,6~]dec-8-ene-3,5-dione. These compounds, which had moderate binding affinities to CypA (i.e., K(d) values in the low micromolar range), provide new molecular scaffolds that might be useful in the development of CypA-targeted diagnostic imaging or therapeutic agents for lung cancer.
authors.affiliation: Department of Chemistry, Duke University, Durham, NC 27708-0346, USA.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Dearmond
authors.forename: Graham M
authors.initials: GM
authors.lastname: West
authors.forename: Victor
authors.initials: V
authors.lastname: Anbalagan
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Campa
authors.forename: Edward F
authors.initials: EF
authors.lastname: Patz
authors.forename: Michael C
authors.initials: MC
authors.lastname: Fitzgerald
mesh_terms: D021984:Cyclophilin A / Q000037:antagonists & inhibitors / Q000378:metabolism*; D041961:Deuterium Exchange Measurement / Q000379:methods*; D055808:Drug Discovery / Q000379:methods*; D006801:Humans; D008024:Ligands; D013058:Mass Spectrometry / Q000379:methods*; D054852:Small Molecule Libraries / Q000032:analysis / Q000494:pharmacology
chemical_list: D008024:Ligands; D054852:Small Molecule Libraries; D021984:Cyclophilin A