Gaali S, Kozany C, Hoogeland B, Klein M, Hausch F. Facile synthesis of a fluorescent cyclosporin a analogue to study cyclophilin 40 and cyclophilin 18 ligands.
ACS Med Chem Lett 2010;
1:536-9. [PMID:
24900244 DOI:
10.1021/ml1001272]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 08/03/2010] [Indexed: 12/11/2022] Open
Abstract
There are strong indications for the involvement of cyclophilin 40 in diseases caused by misregulation of steroid hormone receptors, like prostate or breast cancer. To identify novel inhibitors for this immunophilin, we developed a simplified fluorescence polarization assay based on the synthesis of a fluorescein-labeled tracer. This tracer was produced by a facile four-step synthesis involving Grubbs metathesis and standard amide bond coupling, to label cyclosporin A with fluorescein. We show the binding of this tracer to Cyp40 and Cyp18 with K D values of 106 ± 13 or 12 ± 1 nM, respectively, by analyzing the anisotropy change and demonstrate its competition with cyclosporin A. Binding data obtained by fluorescence polarization were corroborated by an enzymatic activity assay. The described tracer allows for a robust assay in a high-throughput format to support the development of novel Cyp40 ligands.
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