Chemistry of bifunctional photoprobes - 4. Synthesis of the chromogenic, cleavable, water soluble, and heterobifunctional sulfosuccinimidyl (N-methylamino perfluoroaryl azido benzamido)-ethyl-1,3 '-dithiopropionate: An efficient protein cross-linking agent

Synthesis of a new photo cross-linking agent incorporating chromogenicity, cleavability, and water solubility is described. The high efficiency of nit rene insertion observed upon photolysis of perfluoroaryl azides into organi c solvents and proteins is extended to the design and synthesis of new mult ifunctional cross-linking agents useful for protein-protein interactions. T he new cross-linker sulfosuccinimidyl (perfluorobenzamido)-ethyl-1,3'-dithi opropionate (SFAD) 10 was conjugated to IgG and cross-linked to horseradish peroxidase (HRP). The analysis of the cross-linked product using ELISA ass ays leads to a higher yield of IgG-HRP cross-linked product than that seen with a similar nonfluorinated analog. The efficiency of photo cross-linking by SFAD is also extended to small molecule biotin via CH insertion and che cked for the retention of binding affinity of the cross-linked product. (C) 1998 Academic Press.