RESUMEN
A series of peptidic fluorogenic substrates were synthesized to develop a flow cytometry assay (FACS) to monitor the proteolytic activity of cathepsin C in live cells. Of the 16 substrates tested, (NH(2)-aminobutyric-homophenylalanine)(2)-rhodamine demonstrated the best reactivity and selectivity profile in the FACS assay using the B721 human B-lymphoblastoid cell line. The resulting FACS assay was validated through correlation of the IC(50) values with a competitive radiolabeling assay against a series of small molecule inhibitors of cathepsin C.
Asunto(s)
Catepsina C/metabolismo , Colorantes Fluorescentes/química , Rodaminas/química , Catepsina C/antagonistas & inhibidores , Línea Celular Tumoral , Citometría de Flujo , Humanos , Concentración 50 Inhibidora , Marcaje Isotópico , Radioisótopos/química , Rodaminas/síntesis química , Especificidad por SustratoRESUMEN
The synthesis and structure-activity relationship of a series of arylaminoethyl amide cathepsin S inhibitors are reported. Optimization of P3 and P2 groups to improve overall physicochemical properties resulted in significant improvements in oral bioavailability over early lead compounds. An X-ray structure of compound 37 bound to the active site of cathepsin S is also reported.