Kinetic mechanism and some properties of glucose-6-phosphate dehydrogenase from sheep brain cortex

Ulusu, Nuriye Nuray; Sengezer, C

doi:10.5505/tjb.2012.83007

Cited by 2 publications

(3 citation statements)

References 29 publications

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“…In contrast, in sheep brain cortex, it followed a Theorell–Chance mechanism. The distinct kinetic mechanisms highlight the various enzyme modifications that have taken place, including post-translational modifications at the molecular level (Ulusu et al 1999 , 2005 ; Ulusu and Tandogan 2006 , 2007 ; Tandogan and Ulusu 2010 ; Ulusu and Sengezer 2012 ).…”

Section: Complexity Of Kinetic Mechanismsmentioning

confidence: 99%

Evolution of Enzyme Kinetic Mechanisms

Ulusu

2015

J Mol Evol

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This review paper discusses the reciprocal kinetic behaviours of enzymes and the evolution of structure–function dichotomy. Kinetic mechanisms have evolved in response to alterations in ecological and metabolic conditions. The kinetic mechanisms of single-substrate mono-substrate enzyme reactions are easier to understand and much simpler than those of bi–bi substrate enzyme reactions. The increasing complexities of kinetic mechanisms, as well as the increasing number of enzyme subunits, can be used to shed light on the evolution of kinetic mechanisms. Enzymes with heterogeneous kinetic mechanisms attempt to achieve specific products to subsist. In many organisms, kinetic mechanisms have evolved to aid survival in response to changing environmental factors. Enzyme promiscuity is defined as adaptation to changing environmental conditions, such as the introduction of a toxin or a new carbon source. Enzyme promiscuity is defined as adaptation to changing environmental conditions, such as the introduction of a toxin or a new carbon source. Enzymes with broad substrate specificity and promiscuous properties are believed to be more evolved than single-substrate enzymes. This group of enzymes can adapt to changing environmental substrate conditions and adjust catalysing mechanisms according to the substrate’s properties, and their kinetic mechanisms have evolved in response to substrate variability.

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Section: Complexity Of Kinetic Mechanismsmentioning

confidence: 99%

Evolution of Enzyme Kinetic Mechanisms

Ulusu

2015

J Mol Evol

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“…Detoxification of xenobiotics, drugs, toxins or heavy metals occurs via glutathione metabolism. GSH is oxidized to GSSG under oxidative stress conditions via glutathione peroxidase (GPx) enzyme and reduced back to GSH by glutathione reductase (GR) enzyme to maintain GSH/GSSG balance by NADPH-dependent mechanism in both cytosol and mitochondria (22)(23)(24)(25)(26)(27)(28). Intracellular GSH concentration and GSH/ GSSG ratio play a major role in the defence mechanism against oxidative stress that is regulated by glutathione dependent enzymes including GR and GPx (26)(27)(28)(29)(30).…”

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confidence: 99%

“…GSH is oxidized to GSSG under oxidative stress conditions via glutathione peroxidase (GPx) enzyme and reduced back to GSH by glutathione reductase (GR) enzyme to maintain GSH/GSSG balance by NADPH-dependent mechanism in both cytosol and mitochondria (22)(23)(24)(25)(26)(27)(28). Intracellular GSH concentration and GSH/ GSSG ratio play a major role in the defence mechanism against oxidative stress that is regulated by glutathione dependent enzymes including GR and GPx (26)(27)(28)(29)(30). NADPH is the limiting substrate for GR activity catalysing the reaction of converting GSSG to GSH, therefore cells exposed to elevated levels of oxidative stress need high PPP activity (2,26,(31)(32)(33)(34)(35).…”

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confidence: 99%

The Possible Role of The Glucose-6-Phosphate Dehydrogenase Enzyme Deficiency in The Polyneuropathies

Aydemir¹,

Ulusu²

2020

J Basic Clin Health Sci

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Glucose is the main energy source of the various types of cells and largely metabolized by either glycolysis or pentose phosphate pathway (PPP). Glucose-6-phosphate dehydrogenase (G6PD, glucose 6-phosphate (G6P): NADP (+) oxidoreductase, EC 1.1.1.49) is the first and rate limiting enzyme of the oxidative branch of the PPP. This enzyme found in many species from bacteria to humans and is found in all cell types. G6PD deficiency is the most common enzyme deficiency affecting 400 million people worldwide. However, moderate G6PD deficiency may not give symptoms but can lead to various neurological and neurodegenerative disorders including polyneuropathies. Both inflammation and oxidative stress play a major role in the formation of the neurological disorders, however, G6PD gives advantage to brain and nerve cells to fight against oxidative stress, neurodegeneration, neuronal survival and aging. In conclusion, G6PD plays vital role to maintain homeostasis of lipid, redox and energy metabolisms. Thus, impairment in the G6PD activity may cause elevated levels of oxidative stress involved in the formation of the neurodegeneration and may involve in the primary cause of idiopathic sensory-motor polyneuropathy.

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Kinetic mechanism and some properties of glucose-6-phosphate dehydrogenase from sheep brain cortex

Cited by 2 publications

References 29 publications

Evolution of Enzyme Kinetic Mechanisms

Evolution of Enzyme Kinetic Mechanisms

The Possible Role of The Glucose-6-Phosphate Dehydrogenase Enzyme Deficiency in The Polyneuropathies

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