Flavokinase

Flavokinase is an enzyme that plays a crucial role in the metabolism of riboflavin, also known as vitamin B2. Its primary function is to catalyze the phosphorylation of riboflavin to flavin mononucleotide (FMN). This phosphorylation step is essential because FMN is the biologically active form of riboflavin. Once converted to FMN, riboflavin can then be further phosphorylated to flavin adenine dinucleotide (FAD), another vital cofactor.

Flavokinase is a member of the nucleoside diphosphatase kinase family. It is found in various organisms, including bacteria and eukaryotes. In humans, flavokinase is encoded by the *FLN1* gene. The enzyme is present in tissues that have high metabolic activity, such as the liver and kidneys.

The activity of flavokinase is important for cellular energy production and redox homeostasis, as FMN and FAD are prosthetic groups for numerous enzymes involved in electron transport chains and metabolic pathways. Defects in flavokinase activity can lead to riboflavin deficiency or impaired riboflavin metabolism, potentially affecting a range of cellular functions. Research into flavokinase continues to explore its precise regulatory mechanisms and its implications in various physiological and pathological conditions.