Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Flavin mononucleotide , reactions with

Bacterial concentrations have also been determined by using the enzyme-catalyzed chemiluminescent reaction of reduced flavin mononucleotide (FMN) with oxygen and aldehydes. The detection limit was reported to be 10 ceUs of E. coli, which contains 7 x 10 g of FMN per ceU (303). [Pg.275]

Bacterial luciferase catalyzes the reaction of reduced flavin mononucleotide (FMNH2) with O2 to form a 4a-peroxyflavin derivative that reacts with a... [Pg.147]

Riboflavin fulfills its role in metabolism as the coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) (Figure 45-10). FMN is formed by ATP-dependent phosphorylation of riboflavin, whereas FAD is synthesized by further reaction of FMN with ATP in which its AMP moiety is transferred to the... [Pg.489]

The varions flavin phosphates and their acetyl derivatives were identified by pH titration, electrophoresis, and H-NMR, which permit direct analysis of crude reaction prodncts as well as rapid purity check of commercial flavin mononucleotide or riboflavin 5 -monophosphate (FMN or 5 -FMN) [7]. Riboflavin 4 -monophosphate was determined as the main by-product of commercial FMN by preparative TLC on cellulose with n-butanol/acetic add/water (5 2 3, v/v) as a solvent [7]. [Pg.239]

It is well known that the selective transport of ions through a mitochondrial inner membrane is attained when the oxygen supplied by the respiration oxidizes glycolysis products in mitochondria with the aid of such substances as flavin mononucleotide (FMN), fi-nicotinamide adenine dinucleotide (NADH), and quinone (Q) derivatives [1-3]. The energy that enables ion transport has been attributed to that supplied by electron transport through the membrane due to a redox reaction occurring at the aqueous-membrane interface accompanied by respiration [1-5],... [Pg.489]

III. SELECTIVE ION TRANSFER AT THE W/0 INTERFACE COUPLED WITH REDOX REACTIONS BETWEEN FLAVIN MONONUCLEOTIDE IN W AND A FERROCENE DERIVATIVE IN O AND CO2 EVOLUTION [19,21]... [Pg.497]

Physiologic electron acceptors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) produced similar effects on cathodic hydrogen evolution from mild steel as achieved with methyl viologen (Bryant and Laishley 1990). These experimental results showed that the mild steel rods reacting with phosphate can preferential act as electron donors for the reduction of low-potential electron carriers. All hydrogenases catalyze a reversible reaction for the formation and oxidation of hydrogen, which requires low-potential electron carriers for the enzyme activity (Church et al. 1988 Fauque et al. 1988). [Pg.254]

The flavin-based coenzymes flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) are associated with a wide variety of enzymes that catalyze reactions in critical biosynthetic and catabolic processes (Fig. 16). Unlike other coenzymes, the reactions catalyzed do not conserve specific mechanistic pathways. In each case the apoenzyme serves to steer the course of the reaction through specific interactions with substrate and coenzyme [55]. Nonetheless, there are common features of the interactions of the apoenzymes with the flavin which can be exploited in the design of functional peptides and proteins. [Pg.23]

Semisynthetic enzymatic oxidation of peptide alcohols employs equine liver alcohol dehydrogenase. Amino alcohols with nonpolar side chains and Z-Om[CH2OH] worked as effective substrates while polar amino alcohols such as H-Arg[CH2OH] and H-Lys[CH2OH] failed as substrates. To attain complete oxidation, semicarbazide was present in the reaction mixture to immediately trap the aldehyde, and flavin mononucleotide was used to oxidize the NADH to NAD+, which serves to oxidize the alcohol 41] Configurational stability was confirmed by NMR spectroscopy as in the case of Ac-Phe[CH2OH], which was prepared by sodium borohydride reduction of Ac-Phe-H 4 1... [Pg.209]

In the following, the outline of the redox reaction between O2 in W and decamethyl-ferrocene in O catalysed by flavin mononucleotide (FMN) in W evolving CO2, which was elucidated by applying VCTIES, will be introduced [12,13]. The selective ion transfer controlled by the redox reaction will also be discussed. The respiration mimetic reactions such as the redox reactions between -nicotinamide adenine dinucleotide and ascorbic acid or oxygen in W and quinone derivatives or hydroquinone derivatives, respectively, were also investigated with the aid of VCTIES [14,15], though they are not introduced here. [Pg.135]

HPAH from A. baumannii is isolated as a reductase that contains flavin mononucleotide (FMN) and an oxygenase without flavin. The reductase is a homodimer with monomer molecular weight of 35,000, whereas the oxygenase is a homotetramer with monomer mass of 47,000 Da. The two proteins together carry out a catalytic reaction analogous to that of PHBH curiously, no detectable complex formation exists between the... [Pg.2297]

Reactions with HLADH typically occur at temperatures between 4°C and 25°C and in the pH range of 5 to 10. For catalysis of a reduction the optimum pH is 7 while for the reverse oxidation it is 8. Reaction times vary from a few hours in the most favourable substrates and 2-3 weeks for the slowest. The disadvantage of HLADH has been the high cost of coenzymes. Fortunately, several recycling methods are available that allow reduction of substrates at the research scale (up to 1 kg of substrate).27-30 Por example, the ethanol-coupled method has been used for reduction and flavin mononucleotide (FMN) recycling for oxidation. [Pg.484]

In higher mammals, riboflavin is absorbed readily from the intestines and distributed to all tis.sues. It is the precursor in the biosynthesis of the cocnzyme.s flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). The metabolic functions of this vitamin involve these Iwocoenzymes. which participate in numerous vital oxidation-reduction proces.ses. FMN (riboflavin 5 -phosphate) is produced from the vitamin and ATP by flavokinasc catalysis. This step con be inhibited by phcnothiazincs and the tricyclic antidepressants. FAD originates from an FMN and ATP reaction that involves reversible dinucicotide formation catalyzed by flavin nucleotide pyrophosphorylase. The.se coenzymes function in combination with several enzymes as coenzyme-en-zyme complexes, often characterized as, flavoproteins. [Pg.890]

Coenzymes - Many enzymes require nonprotein coenzymes for catalytic activity.8 These are cosubstrates, and must be constantly reconverted into their active form for catalysis to continue. This is not a problem for growing microorganisms since the normal metabolic processes ensure an adequate supply of coenzymes. However, with purified, or immobilized enzymes, maintaining a sufficient concentration of coenzyme can pose a major problem. Coenzymes are expensive and it is seldom economically feasible to add them in stoichiometric amounts. This is often undesirable for chemical reasons, e.g., the coenzyme may be unstable, or the eventual build-up of high concentrations of its inactive form may Induce displacement of an equilibrium reaction in the opposite direction to that desired.3 It is therefore necessary to use catalytic amounts of coenzymes and to ensure that the active forms are continuously regenerated. Some coenzymes present little or no problem in this regard since they are automatically reformed under the normal aqueous reaction conditions or in the presence of oxygen. These include biotin, pyrldoxal phosphate (PLP), thiamine pyrophosphate, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD).1 ... [Pg.299]


See other pages where Flavin mononucleotide , reactions with is mentioned: [Pg.273]    [Pg.1887]    [Pg.1886]    [Pg.591]    [Pg.371]    [Pg.922]    [Pg.50]    [Pg.162]    [Pg.553]    [Pg.559]    [Pg.569]    [Pg.45]    [Pg.44]    [Pg.638]    [Pg.405]    [Pg.553]    [Pg.559]    [Pg.175]    [Pg.133]    [Pg.70]    [Pg.436]    [Pg.140]    [Pg.155]    [Pg.20]    [Pg.60]    [Pg.922]    [Pg.339]    [Pg.2232]    [Pg.1117]    [Pg.828]    [Pg.232]    [Pg.86]    [Pg.248]    [Pg.167]   


SEARCH



Flavin mononucleotide

Flavine mononucleotide

Flavines

Flavins

Mononucleotides

© 2024 chempedia.info