Herein, we report a two-step deglycosylation mediated by the oxidation of glycoside which is different from traditional glycoside hydrolase (GH) mechanism. Previously, we reported a novel flavin adenine dinucleotide (FAD)-dependent glycoside oxidoreductase (FAD-GO) having deglycosylation activity. Various features of the reaction of FAD-GO such as including mechanism and catalytic residue and s...

Escherichia coli general NAD(P)H:flavin oxidoreductase (Fre) does not have a bound flavin cofactor; its flavin substrates (riboflavin, FMN, and FAD) are believed to bind to it mainly through the isoalloxazine ring. This interaction was real for riboflavin and FMN, but not for FAD, which bound to Fre much tighter than FMN or riboflavin. Computer simulations of Fre.FAD and Fre.FMN complexes showe...

The existence and biochemical functions of flavin adenine dinucleotide (FAD) have been well recognized in plants as well as in other living cells. There are some informa tions concerning the biosynthesis of FAD from flavin mononucleotide (FMN) and ATP by a reversible reaction, catalzyed by FAD pyrophosphorylase in beans (1), yeast (2, 3) and animals (4, 5, 6). On the other hand, the FAD hydroly...

The primary role of the water-soluble vitamin B2 (riboflavin) in cell biology is connected with its conversion into FMN and FAD, the cofactors of a large number of dehydrogenases, oxidases and reductases involved in a broad spectrum of biological activities, among which energetic metabolism and chromatin remodeling. Subcellular localisation of FAD synthase (EC 2.7.7.2, FADS), the second enzyme ...

FAD is a redox cofactor ensuring the activity of many flavoenzymes mainly located in mitochondria but also relevant for nuclear redox activities. The last enzyme in the metabolic pathway producing FAD is FAD synthase (EC 2.7.7.2), a protein known to be localized both in cytosol and in mitochondria. FAD degradation to riboflavin occurs via still poorly characterized enzymes, possibly belonging t...

A monoclonal antibody against 4-aminobenzoate hydroxylase (EC 1.14.13.27) from Agaricus bisporus, a common edible mushroom, has been produced by the fusion of BALB/c mouse spleen cells immunized with the denatured enzyme and P3x63Ag8U1 myeloma cells in order to locate and characterize the catalytic site of the enzyme. The monoclonal antibody immunoblotted the enzyme and immunoprecipitated its a...

Intact human red blood cells can synthesize FAD and FMN from riboflavin. The rate of synthesis of FAD is linearly proportional to the concentration of riboflavin in the medium at levels below 0.9 1 M. With 0.9 1 M riboflavin, the rate of synthesis is about 0.1 m mole FAD/ml. red blood cells/hour. Incubation of red blood cells with riboflavin can result in increased red cell glutathione reductas...

We have studied the functional steps by which Saccharomyces cerevisiae mitochondria can synthesize FAD from cytosolic riboflavin (Rf). Riboflavin uptake into mitochondria took place via a mechanism that is consistent with the existence of (at least two) carrier systems. FAD was synthesized inside mitochondria by a mitochondrial FAD synthetase (EC 2.7.7.2), and it was exported into the cytosol v...

Biosynthesis in vertebrates of long-chain polyunsaturated fatty acids (LC-PUFA) such as arachidonic (ARA; 20:4n-6), eicosapentaenoic (EPA; 20:5n-3) and docosahexaenoic (DHA; 22:6n-3) acids requires the catalysis by fatty acyl desaturases (Fads). A vertebrate Fad with Δ4 activity catalyzing the direct conversion of 22:5n-3 to DHA was discovered in the marine teleost rabbitfish Siganus canalicula...

Flavin adenine dinucleotide (FAD), synthesized from riboflavin, is redox cofactor in energy production and plays an important role in cell survival. More recently, riboflavin deficiency has been linked to developmental disorders, but its role in stem cell differentiation remains unclear. Here, we show that FAD treatment, using DMSO as a solvent, enabled an increase in the amount of intracellula...