In humans, the 2-oxoglutarate-dependent dioxygenases (2-OGDDs) catalyze hydroxylation reactions involved in cell metabolism, the biosynthesis of small molecules, DNA and RNA demethylation, the hypoxic response and the formation of collagen. The reaction is catalyzed by a highly oxidizing ferryl-oxo species produced when the active site non-heme iron engages molecular oxygen. Enzyme activity is specifically stimulated by l-ascorbic acid (ascorbate, vitamin C), an effect not well mimicked by other reducing agents. In this perspective article we discuss the reliance of the 2-OGDDs on ascorbate availability. We draw upon findings from studies with different 2-OGDDs to piece together a comprehensive theory for the specific role of ascorbate in supporting enzyme activity. Our discussion centers on the capacity for ascorbate to act as an efficient radical scavenger and its propensity to reduce and chelate transition metals. In addition, we consider the evidence supporting stereospecific binding of ascorbate in the enzyme active site.
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http://dx.doi.org/10.1021/acs.jmedchem.4c02342 | DOI Listing |
J Med Chem
January 2025
Ma̅tai Ha̅ora - Centre for Redox Biology and Medicine, Department of Biomedical Science and Pathology, University of Otago, Christchurch, Christchurch 8140, New Zealand.
In humans, the 2-oxoglutarate-dependent dioxygenases (2-OGDDs) catalyze hydroxylation reactions involved in cell metabolism, the biosynthesis of small molecules, DNA and RNA demethylation, the hypoxic response and the formation of collagen. The reaction is catalyzed by a highly oxidizing ferryl-oxo species produced when the active site non-heme iron engages molecular oxygen. Enzyme activity is specifically stimulated by l-ascorbic acid (ascorbate, vitamin C), an effect not well mimicked by other reducing agents.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
January 2025
School of Cardiovascular and Metabolic Medicine & Sciences, British Heart Foundation Centre of Research Excellence, King's College London, SE5 9NU London, UK.
Cardiovascular disease (CVD) is the most prevalent cause of mortality and morbidity in the Western world. A common underlying hallmark of CVD is the plaque-associated arterial thickening, termed atherosclerosis. Although the molecular mechanisms underlying the aetiology of atherosclerosis remain unknown, it is clear that both its development and progression are associated with significant changes in the pattern of DNA methylation within the vascular cell wall.
View Article and Find Full Text PDFBiol Methods Protoc
December 2024
Department of Biotechnology, Indian Institute of Technology Hyderabad (IITH), Sanga Reddy, Kandi, Telangana 502284, India.
Non-haem iron (Fe) and 2-oxoglutarate(2OG)-dependent dioxygenases catalyse various biological reactions. These enzymes couple the oxidative decarboxylation of 2OG to the hydroxylation of the substrates. While some of these enzymes are reported to have multiple substrates, the substrate remains unknown for many of the enzymes.
View Article and Find Full Text PDFNew Phytol
February 2025
Department of Fruit Tree Sciences, The Volcani Center ARO, 68 HaMaccabim Road, Rishon LeZion, 7505101, Israel.
Furanocoumarins (FCs) are plant defence compounds derived from the phenylpropanoid pathway via the coumarin umbelliferone that harbour some therapeutic benefits yet are the underlying cause of 'grapefruit-drug interactions' in humans. Most of the pathway genes have not been identified in citrus. We employed a genetic/Omics approach on citrus ancestral species and F1 populations of mandarin × grapefruit and mandarin × pummelo.
View Article and Find Full Text PDFJ Biochem
December 2024
Laboratory of Cancer Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan.
Since low oxygen conditions below physiological levels, hypoxia, is associated with various diseases, it is crucial to understand the molecular basis behind cellular response to hypoxia. Hypoxia-inducible factors (HIFs) have been revealed to primarily orchestrate the hypoxia response at the transcription level and have continuously attracted great attention over the past three decades. In addition to these hypoxia-responsive effector proteins, 2-oxoglutarate-dependent dioxygenase (2-OGDD) superfamily including prolyl-4-hydroxylase domain-containing proteins (PHDs) and factor inhibiting HIF-1 (FIH-1) have attracted even greater attention in recent years as factors that act as direct oxygen sensors due to their necessity of oxygen for the regulation of the expression and activity of the regulatory subunit of HIFs (HIF-α).
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