Flavin Mononucleotide (FMN)
a biomolecule produced from riboflavin (vitamin B2
) by the enzyme riboflavin kinase and functions as prosthetic group of various oxidoreductases including NADH dehydrogenase as well as cofactor in biological blue-light photo receptors. During catalytic cycle, the reversible interconversion of oxidized (FMN), semiquinone (FMNH•
) and reduced (FMNH2
) forms occurs in the various oxidoreductases. FMN is a stronger oxidizing agent than NAD and is particularly useful because it can take part in both one and two electron transfers. In its role as blue-light photo receptor (oxidized) FMN stands out from the 'conventional' photo receptors as the signaling state is not a E/Z isomerization.It is the principal form in which riboflavin is found in cells and tissues. It requires more energy to produce, but is more soluble than riboflavin.