Cystathionine β-lyase, an enzyme crucial for bacterial virulence [1], catalyzes the conversion of cystathionine into homocysteine, representing the penultimate step in the biosynthesis of methionine.

Cystathionine β-lyase, at a concentration of 25 nM and incubation time of 10 minutes, catalyzes the conversion of L-(+)-cysteine (100 μM) into homocysteine. The activity of cystathionine β-lyase can be detected by monitoring the formation of free thiols at 412 nm using 5,5′-dithio-bis-(2-nitrobenzoic acid) [1].