text: Most halogenated << cysteine S-conjugates >> are metabolized by cysteine S-conjugate [[ beta-lyases ]] to pyruvate, ammonia, and an alpha-chloroenethiolate (with DCVC) or an alpha-difluoroalkylthiolate (with TFEC) that may eliminate halide to give a thioacyl halide, which reacts with epsilon-amino groups of lysine residues in proteins.