flavoproteins
Definition: Flavoproteins are proteins that contain a nucleic acid derivative of riboflavin (vitamin B2): the flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN).
Flavoproteins are involved in a wide array of biological processes, including, but by no means limited to, bioluminescence, removal of radicals contributing to oxidative stress, photosynthesis, DNA repair, and apoptosis.
The spectroscopic properties of the flavin cofactor make it a natural reporter for changes occurring within the active site; this makes flavoproteins one of the most-studied enzyme families.