The identification of a variant form of cystathionine β-synthase in nematodes

Characterization of the physical and catalytic properties of the enzyme responsible for nematode “activated l -serine sulfhydrase” activity ( l -cysteine + R-SH → cysteine thioether + H 2 S) has led to its identification as a novel, variant form (allelozyme) of cystathionine β-synthase that is distinct from a mammalian-type synthase also present in nematodes. Additional work has demonstrated the ability of live Panagrellus redivivus to produce H 2 [ 35 S] from exogenous l -[ 35 S]cysteine and 2-mercaptoethanol, thus providing preliminary evidence for the in vivo operation of the activated l -serine sulfhydrase reaction in nematodes.