A Cyclosporin Derivative Discriminates between Extracellular and Intracellular Cyclophilins


  • This work was supported by the Deutsche Forschungsgemeinschaft (SFB 610) and the National Institutes of Health (AI067254). We thank Dr. Helton Santiago for technical assistance.


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Trimesic acid amide serves as a scaffold for a lipophilic cyclophilin inhibitor, a fluorescent rhodamine dye (TAMRA), and a (D-Glu)6 oligopeptide residue. Although the affinity of 1 for intracellular cyclophilin A (CypA) is very high, fluorescence measurements indicate complete exclusion from the cell. CypA-induced chemotaxis of lymphocytes is inhibited by 1 since extracellular cyclophilins are responsible for the physiological signal.