LEVELS OF ENZYMES FOR BIOSYNTHESIS AND DEGRADATION OF FLAVINS IN SPINACHS

The levels of the enzymes involved in the biosynthesis and degradation of flavin compounds in spinachs were investigated. 1. These enzymes are localized in the cytoplasm of the cell. 2. The activities of riboflavin synthetase, riboflavin kinase and FAD pyrophosphorylase are distributed consistently. 3. Although the activity of hydrolyzing FMN by the acid phosphatase was considerably higher than that of riboflavin kinase, it was strongly inhibited by the nucleotides, inorganic phosphates and metallic ions. 4. The low affinity of FMN to the acid phosphatase and its low content in green leaves may to decrease the rate of FMN hydrolysis in vivo.