Preparation of flavocoenzyme isotopologues by biotransformation of purines.

摘要: Isotope-labeled flavins are crucial reporters for many biophysical studies of flavoproteins. A purine-deficient Escherichia coli strain engineered expression the ribAGH genes Bacillus subtilis converts isotope-labeled purine supplements into riboflavin precursor, 6,7-dimethyl-8-ribityllumazine, with yields up to 40%. The fermentation products can subsequently be converted and cognate flavocoenzymes, FMN FAD, by in vitro biotransformation better than 90% yield. Using this approach, more 100 single or multiple 13C-, 15N-, 17O-, 18O-labeled isotopologues these cofactors ligands become easily accessible, enabling advanced ligand-based spectroscopy flavoproteins lumazine receptor proteins at unprecedented resolution.