The Recognition of Glycolate Oxidase Apoprotein with Flavin Analogs in Higher Plants

2004 ◽  
Vol 36 (4) ◽  
pp. 290-296 ◽  
Author(s):  
Wei-Jun Wang ◽  
Jing-Quan Huang ◽  
Chong Yang ◽  
Jiu-Jiu Huang ◽  
Ming-Qi Li
Keyword(s):  
Kinetic Analysis ◽  
Inorganic Phosphate ◽  
Flavin Adenine Dinucleotide ◽  
Brassica Campestris ◽  
Higher Plants ◽  
Competitive Binding ◽  
Glycolate Oxidase ◽  
Flavin Mononucleotide ◽  
Protein Fluorescence ◽  
Inhibition Effect

Abstract The dependence of glycolate oxidase apoprotein (apoGO) activity on flavin analogs was surveyed in 9 higher plants from 7 families. Activities of all apoGOs depended not only on flavin mononucleotide (FMN) but also on flavin adenine dinucleotide (FAD), but not on riboflavin. The kinetic analysis showed that FMN was the optimum cofactor for apoGO from leaves of Brassica campestris. In plant kingdom, FMN, FAD and riboflavin are three flavin analogs with very similar structure, and they could coexist and be inter-converted from each other, so the question is how the apoprotein of glycolate oxidase (GO) recognized these flavin analogs. No inhibition effect of riboflavin on the activity of apoGO with FMN or FAD was found and no obvious quenching of riboflavin or apoGO protein fluorescence was detected with the addition of apoGO or riboflavin, respectively. These results indicated that riboflavin did not bind to apoGO tightly like FMN and FAD. Inorganic phosphate (Pi) did inhibit the activity of GO, and kinetic analysis revealed that this inhibition was caused by the competitive binding to apoGO between Pi and FMN. This competitive binding was further confirmed by the inhibition of Pi to the quenching of FMN and apoGO protein fluorescence with apoGO and FMN, respectively. It was suggested that the 5'-phosphate group of FMN or FAD may play a key role in the recognition and binding of riboflavin analog cofactors with apoGO.

scholarly journals Ectopic Expression of the Rice Lumazine Synthase Gene Contributes to Defense Responses in Transgenic Tobacco

2010 ◽  
Vol 100 (6) ◽  
pp. 573-581 ◽  
Author(s):  
Tingquan Wu ◽  
An Guo ◽  
Yanying Zhao ◽  
Xiaomeng Wang ◽  
Ying Wang ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Transgenic Tobacco ◽  
Plant Defenses ◽  
Higher Plants ◽  
Synergistic Effects ◽  
Ectopic Expression ◽  
Defense Responses ◽  
Flavin Mononucleotide ◽  
Lumazine Synthase ◽  
Ethylene Content

Lumazine synthase (LS) catalyzes the penultimate reaction in the multistep riboflavin biosynthesis pathway, which is involved in plant defenses. Plant defenses are often subject to synergistic effects of jasmonic acid and ethylene whereas LS is a regulator of jasmonic acid signal transduction. However, little is known about whether the enzyme contributes to defense responses. To study the role of LS in plant pathogen defenses, we generated transgenic tobacco expressing the rice (Oryza sativa) LS gene, OsLS. OsLS was cloned and found to have strong identity with its homologues in higher plants and less homology to microbial orthologues. The OsLS protein localized to chloroplasts in three OsLS-expressing transgenic tobacco (LSETT) lines characterized as enhanced in growth and defense. Compared with control plants, LSETT had higher content of both riboflavin and the cofactors flavin mononucleotide and flavin adenine dinucleotide. In LSETT, jasmonic acid and ethylene were elevated, the expression of defense-related genes was induced, levels of resistance to pathogens were enhanced, and resistance was effective to viral, bacterial, and oomycete pathogens. Extents of OsLS expression correlated with increases in flavin, jasmonic acid, and ethylene content, and correlated with increases in resistance levels, suggesting a role for OsLS in defense responses.

scholarly journals Gamma Radiolysis of Flavin Mononucleotide and Flavin-Adenine Dinucleotide in Aqueous Solution

1991 ◽  
Vol 64 (8) ◽  
pp. 2532-2538 ◽  
Author(s):  
Abhijit Saha ◽  
Parikshit Chandra Mandal ◽  
Sudhindra Nath Bhattacharyya
Keyword(s):  
Aqueous Solution ◽  
Flavin Adenine Dinucleotide ◽  
Flavin Mononucleotide ◽  
Gamma Radiolysis

Enhanced riboflavin incorporation into flavins in newborn riboflavin-deficient rats.

1977 ◽  
Vol 233 (5) ◽  
pp. E397
Author(s):  
C Muttart ◽  
R Chaudhuri ◽  
J Pinto ◽  
R S Rivlin
Keyword(s):  
Subcutaneous Injection ◽  
Flavin Adenine Dinucleotide ◽  
The Other ◽  
Flavin Mononucleotide ◽  
Newborn Rats ◽  
Riboflavin Deficiency ◽  
Riboflavin Deficient ◽  
Covalently Bound

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.

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

1995 ◽  
Vol 15 (1) ◽  
pp. 264-271 ◽  
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.

scholarly journals 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 ◽  
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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