Glutathione Reductase: Stimulation in Normal Subjects by Riboflavin Supplementation

Beutler, Ernest

doi:10.1126/science.165.3893.613

Cited by 103 publications

(30 citation statements)

References 16 publications

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“…riboflavin [6]. There is interest in the mechanism of action of glutathione reductase as a representative example of flavin enzymes.…”

mentioning

confidence: 99%

“…Although haemolytic anaemias have been associated with glutathione reductase deficiency, a partial depression of activity of the red cell enzyme is common, and is connected with the incomplete saturation of the apoenzyme with its prosthetic group, FAD [5]. This condition could arise from an inadequate intake of riboflavin [6]. There is interest in the mechanism of action of glutathione reductase as a representative example of flavin enzymes.…”

mentioning

confidence: 99%

“…This condition could arise from an inadequate intake of Enzyme. Glutathione reductase (EC 1.6.4.2).riboflavin [6]. There is interest in the mechanism of action of glutathione reductase as a representative example of flavin enzymes.…”

mentioning

confidence: 99%

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Human Glutathione Reductase: Purification of the Crystalline Enzyme from Erythorocytes

Worthington

Rosemeyer

1974

European Journal of Biochemistry

209

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Glutathione reductase from human erythrocytes has been purified 40000-fold in 10 steps with an overall yield of 36 %.The procedure included bulk separations on DEAE-Sephadex and CM-Sephadex, gel-filtration on Sephadex G-200, and salt fractionation with ammonium sulphate. The purified enzyme was crystallised from aqueous solution.The final preparation had a specific activity of 240 units/mg. The purification procedure was completed in 4 weeks, and gave 40 mg enzyme from 35 1 blood. The schedule for glutathione reductase allowed the concurrent isolation of glucose-6-phosphate dehydrogenase and 6-phosphogluconate deh ydrogenase.In solutions of thiols, the glutathione reductase preparation was homogeneous, as indicated by gel-filtration, ultracentrifugation and electrophoresis. In the absence of thiols, the enzyme showed a tendency to form aggregates. Some of the physical properties of the enzyme are discussed in relation to previous difficulties encountered in its isolation.Glutathione reductase catalyses the reaction between the oxidised form of glutathione and NADPH [1,21:The NADPH for the above reaction is provided by the initial steps of the hexosemonophosphate pathway involving glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. These two dehydrogenases and glutathione reductase therefore provide a sequence of reactions whereby NADPH is produced and used to maintain glutathione in the reduced state. The reduced glutathione contributes to the viability of the erythrocyte by stabilising other thiols, including those in the cell membrane, in haemoglobin and in the cellular enzymes [3,4]. Although haemolytic anaemias have been associated with glutathione reductase deficiency, a partial depression of activity of the red cell enzyme is common, and is connected with the incomplete saturation of the apoenzyme with its prosthetic group, FAD [5]. This condition could arise from an inadequate intake of Enzyme. Glutathione reductase (EC 1.6.4.2).riboflavin [6]. There is interest in the mechanism of action of glutathione reductase as a representative example of flavin enzymes. The catalytic process is thought to proceed through single electron transfer mediated by the semiquinone form of FAD [7]. However, the sequence of steps in the catalytic mechanism is not clear.Despite the interesting features of the catalytic process and the apparent importance of glutathione reductase to the stability of the red cell, there is limited information on this enzyme relating to its cellular concentration, specific activity and its physical and catalytic properties. This lack of information arises from the difficulty in obtaining sufficient material from erythrocytes for subsequent study of the physicochemical properties of the enzyme. Thus the previous attempts at isolation of glutathione reductase from erythrocytes have only approached purity by a sacrifice of most of the enzyme [8 -101. The previous yields of purified material ranged from 0.3 [lo] to 1.3 mg Previous work in this laboratory has been carried out on th...

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“…riboflavin [6]. There is interest in the mechanism of action of glutathione reductase as a representative example of flavin enzymes.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

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Human Glutathione Reductase: Purification of the Crystalline Enzyme from Erythorocytes

Worthington

Rosemeyer

1974

European Journal of Biochemistry

209

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“…Two enzymes associated with ROS trapping by GSH, glutathione peroxydase (Gpx) and glutathione reductase (Gred), which could help to maintain the GSH content of the cells, are respectively dependent on vitamin B6 [67] and B2 [68]. The two vitamins undergo extensive oxidative degradation after ROS trapping [69,70] and the depletion of the mitochondrial content of the 2 vitamins, can aggravate the detrimental effect of high rates of ROS production.…”

Section: Ros Formation In the Mitochondria Of Placental And Fetal Tismentioning

confidence: 99%

“…Conflicting observations are obtained on the role of vitamin B1 deficiency in gestation failure: secretion of pituitary hormones or estrogen do not seem to be impaired despite a loss of appetite in gestating rats [57], while this vitamin can be recruited and activated in cells of the pituitary or blood vessel walls scavenging damaged cell components after an episode of ischemia [105] and is also an efficient ROS trapping component [59]. Increased rates of ROS fluxes have been reported in vitamin A, B2, B6, B9 or B12 deficiencies [60,94,[106][107][108] which, together with the ROS trapping ability of these compounds [21,60,61,69,70,109,110], points to some relationship to ROS phenomena, in addition to their effect on the control of gene expression and metabolism [29,65,67,68,[110][111][112].…”

Section: Defense Against Ros and The Outcome Of Gestationmentioning

confidence: 99%

Gestation linked radical oxygen species fluxes and vitamins and trace mineral deficiencies in the ruminant

2006

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-In mammals, radical oxygen species (ROS) are essential factors of cell replication, differentiation and growth (oxidative signal), notably during gestation, but are also potentially damaging agents. In Women, ROS play a role in remodeling of uterine tissues, implantation of the embryo, settlement of the villi and development of blood vessels characteristic of gestation. The body stores of vitamins and minerals of gestating females are used to keep ROS fluxes at a level corresponding to oxidative signals and to prevent an imbalance between their production and scavenging (oxidative stress), which would be detrimental to the mother and fetus. There is some evidence that, although based on different regulatory mechanisms, most of the effects of ROS reported in humans also occur in pregnant ruminant females, some of which have been actually reported. Many vitamins and trace elements have dual effects in the organism of mammals: (a) they are involved in the control of metabolic pathways or/and gene expression, (b) but most of the time they also display ROS trapping activity or their deficiencies induce high rates of ROS production. Deficiencies induce different disorders of gestation and can be induced by different kinds of stress. An example is given, corresponding to the decreased contents of cobalt of forages, when exposed to sustained heavy rains, so that the supply of vitamins B12 to the organism of the ruminant that grazes them is reduced and failure of gestation is induced. Outdoor exposure of ruminants to adverse climatic conditions by itself can increase the vitamin and trace element requirements. Adaptation of production systems taking into account these interactions between gestation and sources of stress or change of the quality of feeding stuffs as well as further developments of knowledge in that field is necessary to promote sustainable agricultural practices.gestation / ovine / bovine / vitamins / trace elements / antioxidant enzymes / radical oxygen species / radical phenomena

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Epidermal Changes in Vitamin B12 Deficiency

Gilliam¹

1973

Arch Dermatol

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Glutathione Reductase: Stimulation in Normal Subjects by Riboflavin Supplementation

Cited by 103 publications

References 16 publications

Human Glutathione Reductase: Purification of the Crystalline Enzyme from Erythorocytes

Human Glutathione Reductase: Purification of the Crystalline Enzyme from Erythorocytes

Gestation linked radical oxygen species fluxes and vitamins and trace mineral deficiencies in the ruminant

Epidermal Changes in Vitamin B12 Deficiency

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