Pharmacokinetic Profile of Flavin Adenine Dinucleotide, Flavin Mononucleotide and Riboflavin Following Intravenous Administration of Riboflavin or Its Coenzymes in Rats

The incorporation of a subcutaneous injection of [14C]riboflavin (2.5 muCi/100 g body wt) into flavin mononucleotide (FMN), flavin adenine dinucleotide (FAD), and flavins bound covalently to proteins was determined at 1, 6, and 18 h in liver, cerebrum, and cerebellum from progeny of normal and maternally riboflavin-deficient Holtzman rats. Radioactivity remaining as riboflavin was also determined under these circumstances. Experiments were initiated within 24 h of birth. In both groups of newborn rats, the incorporation of radioactive riboflavin into covalently bound flavins in liver and brain proceeded more slowly than into the other flavin fractions. In addition, radioactivity incorporated into covalently bound flavins comprised a relatively smaller proportion of the total amount incorporated in brain than in liver. In progeny of riboflavin-deficient dams, an increased rate of incorporation of riboflavin into all three flavin derivatives, particularly FAD, was observed in liver and brain, compared to results in normal progeny. These data provide evidence that maternal riboflavin deficiency enhances the incorporation of riboflavin into tissue flavins in liver, cerebrum, and cerebellum from newborn rats.

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Pharmacokinetic profile of RPH-203, a RANKL blocker, following subcutaneous and intravenous administration in the Cynomolgus monkey

Toxicology Letters ◽

10.1016/j.toxlet.2014.06.568 ◽

2014 ◽

Vol 229 ◽

pp. S165

Author(s):

Yan Lavrovsky ◽

Shorena Archuadze ◽

Timi Oshodi ◽

Pankaj Dwivedi

Keyword(s):

Intravenous Administration ◽

Cynomolgus Monkey ◽

Pharmacokinetic Profile

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Cloning and characterization of FAD1, the structural gene for flavin adenine dinucleotide synthetase of Saccharomyces cerevisiae.

Molecular and Cellular Biology ◽

10.1128/mcb.15.1.264 ◽

1995 ◽

Vol 15 (1) ◽

pp. 264-271 ◽

Cited By ~ 63

Author(s):

M Wu ◽

B Repetto ◽

D M Glerum ◽

A Tzagoloff

Keyword(s):

Saccharomyces Cerevisiae ◽

Flavin Adenine Dinucleotide ◽

Genomic Library ◽

Sequence Similarity ◽

Complementation Group ◽

Flavin Mononucleotide ◽

Synthetase Activity ◽

Multicopy Plasmid ◽

Multiple Copies ◽

Extragenic Suppression

The FAD1 gene of Saccharomyces cerevisiae has been selected from a genomic library on the basis of its ability to partially correct the respiratory defect of pet mutants previously assigned to complementation group G178. Mutants in this group display a reduced level of flavin adenine dinucleotide (FAD) and an increased level of flavin mononucleotide (FMN) in mitochondria. The restoration of respiratory capability by FAD1 is shown to be due to extragenic suppression. FAD1 codes for an essential yeast protein, since disruption of the gene induces a lethal phenotype. The FAD1 product has been inferred to be yeast FAD synthetase, an enzyme that adenylates FMN to FAD. This conclusion is based on the following evidence. S. cerevisiae transformed with FAD1 on a multicopy plasmid displays an increase in FAD synthetase activity. This is also true when the gene is expressed in Escherichia coli. Lastly, the FAD1 product exhibits low but significant primary sequence similarity to sulfate adenyltransferase, which catalyzes a transfer reaction analogous to that of FAD synthetase. The lower mitochondrial concentration of FAD in G178 mutants is proposed to be caused by an inefficient exchange of external FAD for internal FMN. This is supported by the absence of FAD synthetase activity in yeast mitochondria and the presence of both extramitochondrial and mitochondrial riboflavin kinase, the preceding enzyme in the biosynthetic pathway. A lesion in mitochondrial import of FAD would account for the higher concentration of mitochondrial FMN in the mutant if the transport is catalyzed by an exchange carrier. The ability of FAD1 to suppress impaired transport of FAD is explained by mislocalization of the synthetase in cells harboring multiple copies of the gene. This mechanism of suppression is supported by the presence of mitochondrial FAD synthetase activity in S. cerevisiae transformed with FAD1 on a high-copy-number plasmid but not in mitochondrial of a wild-type strain.

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Calculation of the Geometries and Infrared Spectra of the Stacked Cofactor Flavin Adenine Dinucleotide (FAD) as the Prerequisite for Studies of Light-Triggered Proton and Electron Transfer

Biomolecules ◽

10.3390/biom10040573 ◽

2020 ◽

Vol 10 (4) ◽

pp. 573

Author(s):

Martina Kieninger ◽

Oscar N. Ventura ◽

Tilman Kottke

Keyword(s):

Infrared Spectra ◽

Density Functional ◽

Flavin Adenine Dinucleotide ◽

Hydroxyl Group ◽

Flavin Mononucleotide ◽

Experimental Investigations ◽

Adenine Ring ◽

Π Complex ◽

Wide Range ◽

Single Water Molecule

Flavin cofactors, like flavin adenine dinucleotide (FAD), are important electron shuttles in living systems. They catalyze a wide range of one- or two-electron redox reactions. Experimental investigations include UV-vis as well as infrared spectroscopy. FAD in aqueous solution exhibits a significantly shorter excited state lifetime than its analog, the flavin mononucleotide. This finding is explained by the presence of a “stacked” FAD conformation, in which isoalloxazine and adenine moieties form a π-complex. Stacking of the isoalloxazine and adenine rings should have an influence on the frequency of the vibrational modes. Density functional theory (DFT) studies of the closed form of FAD in microsolvation (explicit water) were used to reproduce the experimental infrared spectra, substantiating the prevalence of the stacked geometry of FAD in aqueous surroundings. It could be shown that the existence of the closed structure in FAD can be narrowed down to the presence of only a single water molecule between the third hydroxyl group (of the ribityl chain) and the N7 in the adenine ring of FAD.

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