beta-Cystathionase In Vivo Inactivation by Rhizobitoxine and Role of the Enzyme in Methionine Biosynthesis in Corn Seedlings

Rhizobitoxine has previously been shown to inactivate irreversibly β-cystathionase isolated from spinach. In the present studies, rhizobitoxine was shown to inhibit partially β-cystathionase of spinach and corn seedlings in vivo. An activity of 30 to 40% of normal remained in toxin-treated seedlings of both spinach and corn. Possible reasons for the partial inhibition are discussed.