DESIGN AND SYNTHESIS OF A BIFUNCTIONAL LABEL FOR SELECTION OF BETA-LACTAMASE DISPLAYED ON FILAMENTOUS BACTERIOPHAGE BY CATALYTIC ACTIVITY

A bifunctional activity label 1c has been constructed for the selectio n of active beta-lactamases displayed on filamentous bacteriophage. It features an original 6-sulfonylamido-penam sulfone moiety, as beta-la ctamase suicide-inhibitor, and a biotinyl residue, for separation by a ffinity chromatography, connected through a linker including a cleavab le disulfide bond. The inhibitor 28 resulted from coupling of methoxym ethyl 6-aminopenicillinate 8 with N-protected (aminoethoxy)ethoxyethan esulfonyl chloride 23, followed by oxidation into the corresponding su lfone 25, and usual deprotections. The biotinyl ester 32 reacted with 3-(2-aminoethyldithio)propanoic acid 31 as linker, to give 33 which wa s further activated as pentafluorophenol ester 34b. Final coupling of the building blocks 28 and 34b gave the target label 1c. Copyright (C) 1996 Elsevier Science Ltd