Specific enzyme inhibitors in vitamin biosynthesis. Part 6. Identification of an affinity chromatography ligand for the purification of riboflavin synthase

Abstract

The carbodi-imide-mediated condensation of the 7-oxolumazine (1) with amino-functionalised Sepharose at pH 4–5 gave a polymeric material which was effective in the purification of riboflavin synthase by affinity chromatography. The u.v. chromophore of this polymer-supported material was different from that of the 7-oxolumazine. Investigation of an analogous model reaction in free solution has led to a tentative identification of this affinity ligand. An explanation for the ability of this compound to bind to the enzyme is presented which suggests that it may be a ‘reaction co-ordinate’ analogue.