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Microbiology Spectrum Aug 2023The xanthine oxidoreductase (XOR) family are metal-containing enzymes that use the molybdenum cofactor (Moco), 2Fe-2S clusters, and flavin adenine dinucleotide (FAD) for...
The xanthine oxidoreductase (XOR) family are metal-containing enzymes that use the molybdenum cofactor (Moco), 2Fe-2S clusters, and flavin adenine dinucleotide (FAD) for their catalytic activity. This large molybdoenzyme family includes xanthine, aldehyde, and CO dehydrogenases. XORs are widely distributed from bacteria to humans due to their key roles in the catabolism of purines, aldehydes, drugs, and xenobiotics, as well as interconversions between CO and CO. Assessing the effect of excess metals on the Rubrivivax gelatinosus bacterium, we found that exposure to copper (Cu) or cadmium (Cd) caused a dramatic decrease in the activity of a high-molecular-weight soluble complex exhibiting nitroblue tetrazolium reductase activity. Mass spectrometry and genetic analyses showed that the complex corresponds to a putative CO dehydrogenase (pCOD). Using mutants that accumulate either Cu or Cd in the cytoplasm, we show that Cu or Cd is a potent inhibitor of XORs (pCOD and the xanthine dehydrogenase [XDH]) . This is the first demonstration that Cu affects Moco-containing enzymes. The specific inhibitory effect of these compounds on the XOR activity is further supported by direct addition of competing metals to protein extracts. Moreover, emphasis is given on the inhibitory effect of Cu on bovine XOR, showing that the XOR family could be a common target of Cu. Given the conservation of XOR structure and function across the tree of life, we anticipate that our findings could be transferable to other XORs and organisms. The high toxicity of Cu, Cd, Pb, As, and other metals arises from their ability to cross membranes and target metalloenzymes in the cytoplasm. Identifying these targets provides insights into the toxicity mechanisms. The vulnerability of metalloenzymes arises from the accessibility of their cofactors to ions. Accordingly, many enzymes whose cofactors are solvent exposed are likely to be targets of competing metals. Here, we describe for the first time, with and experiments, a direct effect of excess Cu on the xanthine oxidoreductase family (XOR/XDH/pCOD). We show that toxic metal affects these Moco enzymes, and we suggest that access to the Moco center by Cu ions could explain the Cu inhibition of XORs in living organisms. Human XOR activity is associated with hyperuricemia, xanthinuria, gout arthritis, and other diseases. Our findings highlight XOR as a Cu target and thus support the potential use of Cu in metal-based therapeutics against these diseases.
Topics: Animals; Cattle; Humans; Xanthine Dehydrogenase; Cadmium; Metalloproteins; Metals
PubMed: 37458582
DOI: 10.1128/spectrum.04814-22 -
Journal of the American Heart... Mar 2022Background Preeclampsia, a leading cause of maternal and fetal mortality and morbidity, is characterized by an increase in S-nitrosylated proteins and reactive oxygen...
Background Preeclampsia, a leading cause of maternal and fetal mortality and morbidity, is characterized by an increase in S-nitrosylated proteins and reactive oxygen species, suggesting a pathophysiologic role for dysregulation in nitrosylation and nitrosative stress. Methods and Results Here, we show that mice lacking S-nitrosoglutathione reductase (), a denitrosylase regulating protein S-nitrosylation, exhibit a preeclampsia phenotype, including hypertension, proteinuria, renal pathology, cardiac concentric hypertrophy, decreased placental vascularization, and fetal growth retardation. Reactive oxygen species, NO, and peroxynitrite levels are elevated. Importantly, mass spectrometry reveals elevated placental S-nitrosylated amino acid residues in mice. Ascorbate reverses the phenotype except for fetal weight, reduces the difference in the S-nitrosoproteome, and identifies a unique set of S-nitrosylated proteins in mice. Importantly, human preeclamptic placentas exhibit decreased GSNOR activity and increased nitrosative stress. Conclusions Therefore, deficiency of GSNOR creates dysregulation of placental S-nitrosylation and preeclampsia in mice, which can be rescued by ascorbate. Coupled with similar findings in human placentas, these findings offer valuable insights and therapeutic implications for preeclampsia.
Topics: Alcohol Dehydrogenase; Aldehyde Oxidoreductases; Animals; Female; Mice; Nitric Oxide; Placenta; Pre-Eclampsia; Pregnancy; Reactive Oxygen Species
PubMed: 35191317
DOI: 10.1161/JAHA.121.024008 -
ELife Apr 2024Metabolism and biological functions of the nitrogen-rich compound guanidine have long been neglected. The discovery of four classes of guanidine-sensing riboswitches and...
Metabolism and biological functions of the nitrogen-rich compound guanidine have long been neglected. The discovery of four classes of guanidine-sensing riboswitches and two pathways for guanidine degradation in bacteria hint at widespread sources of unconjugated guanidine in nature. So far, only three enzymes from a narrow range of bacteria and fungi have been shown to produce guanidine, with the ethylene-forming enzyme (EFE) as the most prominent example. Here, we show that a related class of Fe- and 2-oxoglutarate-dependent dioxygenases (2-ODD-C23) highly conserved among plants and algae catalyze the hydroxylation of homoarginine at the C6-position. Spontaneous decay of 6-hydroxyhomoarginine yields guanidine and 2-aminoadipate-6-semialdehyde. The latter can be reduced to pipecolate by pyrroline-5-carboxylate reductase but more likely is oxidized to aminoadipate by aldehyde dehydrogenase ALDH7B . Arabidopsis has three 2-ODD-C23 isoforms, among which Din11 is unusual because it also accepted arginine as substrate, which was not the case for the other 2-ODD-C23 isoforms from Arabidopsis or other plants. In contrast to EFE, none of the three Arabidopsis enzymes produced ethylene. Guanidine contents were typically between 10 and 20 nmol*(g fresh weight) in Arabidopsis but increased to 100 or 300 nmol*(g fresh weight) after homoarginine feeding or treatment with Din11-inducing methyljasmonate, respectively. In 2-ODD-C23 triple mutants, the guanidine content was strongly reduced, whereas it increased in overexpression plants. We discuss the implications of the finding of widespread guanidine-producing enzymes in photosynthetic eukaryotes as a so far underestimated branch of the bio-geochemical nitrogen cycle and propose possible functions of natural guanidine production.
Topics: Guanidine; Mixed Function Oxygenases; Homoarginine; Arabidopsis; Guanidines; Protein Isoforms; 2-Aminoadipic Acid
PubMed: 38619227
DOI: 10.7554/eLife.91458 -
Phytomedicine : International Journal... Aug 2022Oxidative stress plays an important role in the pathology of ischemic stroke. Studies have confirmedthat scutellarin has antioxidant effects against ischemic injury, and...
BACKGROUND
Oxidative stress plays an important role in the pathology of ischemic stroke. Studies have confirmedthat scutellarin has antioxidant effects against ischemic injury, and we also reported that the involvement of Aldose reductase (AR) in oxidative stress and cerebral ischemic injury, in this study we furtherly explicit whether the antioxidant effect of scutellarin on cerebral ischemia injury is related to AR gene regulation and its specific mechanism.
METHODS
C57BL/6N mice (Wild-type, WT) and AR knockout (AR) mice suffered from transient middle cerebral artery occlusion (tMCAO) injury (1 h occlusion followed by 3 days reperfusion), and scutellarin was administered from 2 h before surgery to 3 days after surgery. Subsequently, neurological function was assessed by the modified Longa score method, the histopathological morphology observed with 2,3,5-triphenyltetrazolium chloride (TTC) and hematoxylin-eosin (HE) staining. Enzyme-linked immunosorbent assay (Elisa) was used to detect the levels of ROS, 4-hydroxynonenal (4-HNE), 8-hydroxydeoxyguanosine (8-OHDG), Neurotrophin-3 (NT-3), poly ADP-ribose polymerase-1 (PARP1) and 3-nitrotyrosine (3-NT) in the ischemic penumbra regions. Quantitative proteomics profiling using quantitative nano-HPLC-MS/MS were performed to compare the protein expression difference between AR and WT mice with or without tMCAO injury. The expression of AR, nicotinamide adenine dinucleotide phosphate oxidases (NOX1, NOX2 and NOX4) in the ipsilateral side of ischemic brain were detected by qRT-PCR, Western blot and immunofluorescence co-staining with NeuN.
RESULTS
Scutellarin treatment alleviated brain damage in tMCAO stroke model such as improved neurological function deficit, brain infarct area and neuronal injury and reduced the expression of oxidation-related products, moreover, also down-regulated tMCAO induced AR mRNA and protein expression. In addition, the therapeutic effect of scutellarin on the reduction of cerebral infarction area and neurological function deficits abolished in AR mice under ischemia cerebral injury, which indicated that the effect of scutellarin treatment on tMCAO injury is through regulating AR gene. Proteomic analysis of AR and WT mice indicated AR knockout would affect oxidation reaction even as NADPH related process and activity in mice under cerebral ischemia conditions. Moreover, NOX isoforms (NOX1, NOX2 and NOX4) mRNA and protein expression were significant decreased in neurons of penumbra region in AR mice compared with that in WT mice at 3d after tMCAO injury, which indicated that AR should be the upstream protein regulating NOX after cerebral ischemia.
CONCLUSIONS
We first reported that AR directly regulates NOX subtypes (not only NOX2 but also NOX1 and NOX4) after cerebral ischaemic injury. Scutellarin specifically targets the AR-NOX axis and has antioxidant effects in mice with cerebral ischaemic injury, providing a theoretical basis and accurate molecular targets for the clinical application of scutellarin.
Topics: Aldehyde Reductase; Animals; Antioxidants; Apigenin; Brain Ischemia; Disease Models, Animal; Glucuronates; Infarction, Middle Cerebral Artery; Mice; Mice, Inbred C57BL; Mice, Knockout; NADPH Oxidase 1; Oxidative Stress; Proteomics; RNA, Messenger; Reperfusion Injury; Tandem Mass Spectrometry
PubMed: 35689902
DOI: 10.1016/j.phymed.2022.154214 -
Sensors (Basel, Switzerland) Sep 2022In this work, the enzyme aldehyde reductase, also known as aldose reductase, was synthesized and cloned from a human gene. Spectrophotometric measurements show that in...
In this work, the enzyme aldehyde reductase, also known as aldose reductase, was synthesized and cloned from a human gene. Spectrophotometric measurements show that in presence of the nicotinamide adenine dinucleotide phosphate cofactor (NADPH), the aldehyde reductase catalyzed the reduction of glucose to sorbitol. Electrochemical measurements performed on an electrodeposited poly(methylene green)-modified gold electrode showed that in the presence of the enzyme aldehyde reductase, the electrocatalytic oxidation current of NADPH decreased drastically after the addition of glucose. These results demonstrate that aldehyde reductase is an enzyme that allows the construction of an efficient electrochemical glucose biosensor based on glucose reduction.
Topics: Aldehyde Reductase; Glucose; Gold; Humans; NADP; Sorbitol
PubMed: 36236202
DOI: 10.3390/s22197105 -
Frontiers in Bioengineering and... 2020Aldehydes are a class of highly versatile chemicals that can undergo a wide range of chemical reactions and are in high demand as starting materials for chemical...
Aldehydes are a class of highly versatile chemicals that can undergo a wide range of chemical reactions and are in high demand as starting materials for chemical manufacturing. Biologically, fatty aldehydes can be produced from fatty acyl-CoA by the action of fatty acyl-CoA reductases. The aldehydes produced can be further converted enzymatically to other valuable derivatives. Thus, metabolic engineering of microorganisms for biosynthesizing aldehydes and their derivatives could provide an economical and sustainable platform for key aldehyde precursor production and subsequent conversion to various value-added chemicals. is an excellent host for this purpose because it is a robust organism that has been used extensively for industrial biochemical production. However, fatty acyl-CoA-dependent aldehyde-forming enzymes expressed in thus far have extremely low activities, hence limiting direct utilization of fatty acyl-CoA as substrate for aldehyde biosynthesis. Toward overcoming this challenge, we successfully engineered an alcohol-forming fatty acyl-CoA reductase for aldehyde production through rational design. We further improved aldehyde production through strain engineering by deleting competing pathways and increasing substrate availability. Subsequently, we demonstrated alkane and alkene production as one of the many possible applications of the aldehyde-producing strain. Overall, by protein engineering of a fatty acyl-CoA reductase to alter its activity and metabolic engineering of , we generated strains with the highest reported cytosolic aliphatic aldehyde and alkane/alkene production to date in from fatty acyl-CoA.
PubMed: 33123518
DOI: 10.3389/fbioe.2020.585935 -
Frontiers in Endocrinology 2021Diabetes is a leading cause of cardiovascular morbidity and mortality. Despite numerous treatments for cardiovascular disease (CVD), for patients with diabetes, these... (Review)
Review
Diabetes is a leading cause of cardiovascular morbidity and mortality. Despite numerous treatments for cardiovascular disease (CVD), for patients with diabetes, these therapies provide less benefit for protection from CVD. These considerations spur the concept that diabetes-specific, disease-modifying therapies are essential to identify especially as the diabetes epidemic continues to expand. In this context, high levels of blood glucose stimulate the flux aldose reductase (AR) pathway leading to metabolic and signaling changes in cells of the cardiovascular system. In animal models flux AR in hearts is increased by diabetes and ischemia and its inhibition protects diabetic and non-diabetic hearts from ischemia-reperfusion injury. In mouse models of diabetic atherosclerosis, human AR expression accelerates progression and impairs regression of atherosclerotic plaques. Genetic studies have revealed that single nucleotide polymorphisms (SNPs) of the () is associated with diabetic complications, including cardiorenal complications. This Review presents current knowledge regarding the roles for AR in the causes and consequences of diabetic cardiovascular disease and the status of AR inhibitors in clinical trials. Studies from both human subjects and animal models are presented to highlight the breadth of evidence linking AR to the cardiovascular consequences of diabetes.
Topics: Aldehyde Reductase; Animals; Blood Glucose; Blood Platelets; Cardiovascular Diseases; Cardiovascular System; Diabetes Complications; Diabetes Mellitus; Disease Progression; Enzyme Inhibitors; Glucose; Humans; Hyperglycemia; Mice; Osmosis; Polymers; Polymorphism, Genetic; Rats; Reperfusion Injury
PubMed: 33776930
DOI: 10.3389/fendo.2021.636267 -
Drug Metabolism and Disposition: the... Apr 2023Testosterone exhibits high variability in pharmacokinetics and glucuronidation after oral administration. Although testosterone metabolism has been studied for decades,...
Testosterone exhibits high variability in pharmacokinetics and glucuronidation after oral administration. Although testosterone metabolism has been studied for decades, the impact of UGT2B17 gene deletion and the role of gut bacterial -glucuronidases on its disposition are not well characterized. We first performed an exploratory study to investigate the effect of UGT2B17 gene deletion on the global liver proteome, which revealed significant increases in proteins from multiple biological pathways. The most upregulated liver proteins were aldoketoreductases [AKR1D1, AKR1C4, AKR7A3, AKR1A1, and 7-dehydrocholesterol reductase (DHCR7)] and alcohol or aldehyde dehydrogenases (ADH6, ADH1C, ALDH1A1, ALDH9A1, and ALDH5A). In vitro assays revealed that AKR1D1 and AKR1C4 inactivate testosterone to 5-dihydrotestosterone (5-DHT) and 3,5-tetrahydrotestosterone (3,5-THT), respectively. These metabolites also appeared in human hepatocytes treated with testosterone and in human serum collected after oral testosterone dosing in men. Our data also suggest that 5-DHT and 3α, 5-THT are then eliminated through glucuronidation by UGT2B7 in UGT2B17 deletion individuals. Second, we evaluated the potential reactivation of testosterone glucuronide (TG) after its secretion into the intestinal lumen. Incubation of TG with purified gut microbial -glucuronidase enzymes and with human fecal extracts confirmed testosterone reactivation into testosterone by gut bacterial enzymes. Both testosterone metabolic switching and variable testosterone activation by gut microbial enzymes are important mechanisms for explaining the disposition of orally administered testosterone and appear essential to unraveling the molecular mechanisms underlying UGT2B17-associated pathophysiological conditions. SIGNIFICANCE STATEMENT: This study investigated the association of UGT2B17 gene deletion and gut bacterial -glucuronidases with testosterone disposition in vitro. The experiments revealed upregulation of AKR1D1 and AKR1C4 in UGT2B17 deletion individuals, and the role of these enzymes to inactivate testosterone to 5-dihydrotestosterone and 3, 5-tetrahydrotestosterone, respectively. Key gut bacterial species responsible for testosterone glucuronide activation were identified. These data are important for explaining the disposition of exogenously administered testosterone and appear essential to unraveling the molecular mechanisms underlying UGT2B17-associated pathophysiological conditions.
Topics: Male; Humans; Dihydrotestosterone; Glucuronidase; Testosterone; Liver; Glucuronosyltransferase
PubMed: 36623880
DOI: 10.1124/dmd.122.000975 -
Nutrients Oct 2022In the modern diet, excessive fructose intake (>50 g/day) had been driven by the increase, in recent decades, of the consumption of sugar-sweetened beverages. This... (Review)
Review
In the modern diet, excessive fructose intake (>50 g/day) had been driven by the increase, in recent decades, of the consumption of sugar-sweetened beverages. This phenomenon has dramatically increased within the Caribbean and Latin American regions. Epidemiological studies show that chronic high intake of fructose related to sugar-sweetened beverages increases the risk of developing several non-communicable diseases, such as chronic obstructive pulmonary disease and asthma, and may also contribute to the exacerbation of lung diseases, such as COVID-19. Evidence supports several mechanisms—such as dysregulation of the renin−angiotensin system, increased uric acid production, induction of aldose reductase activity, production of advanced glycation end-products, and activation of the mTORC1 pathway—that can be implicated in lung damage. This review addresses how these pathophysiologic and molecular mechanisms may explain the lung damage resulting from high intake of fructose.
Topics: Aldehyde Reductase; Fructose; Humans; Lung Diseases; Mechanistic Target of Rapamycin Complex 1; Sweetening Agents; Uric Acid
PubMed: 36235741
DOI: 10.3390/nu14194089 -
Molecules (Basel, Switzerland) Mar 2022For the first time, α-glucosidase, α-amylase, aldose reductase, and glycation at multiple stages inhibitory assays were used to explore the antidiabetic potential of...
Inhibitory Effect of Polyphenols from the Whole Green Jackfruit Flour against α-Glucosidase, α-Amylase, Aldose Reductase and Glycation at Multiple Stages and Their Interaction: Inhibition Kinetics and Molecular Simulations.
For the first time, α-glucosidase, α-amylase, aldose reductase, and glycation at multiple stages inhibitory assays were used to explore the antidiabetic potential of whole unripe jackfruit (peel with pulp, flake, and seed). Two polyphenols (phenolic acids) with strong antihyperglycaemic activity were isolated from the methanol extract of whole jackfruit flour (MJ) using activity-guided repeated fractionation on a silica gel column chromatography. The bioactive compounds isolated were identified as 3-(3,4-Dihydroxyphenyl)-2-propenoic acid (caffeic acid: CA) and 4-Hydroxy-3,5-dimethoxybenzoic acid (syringic acid: SA) after various physicochemical and spectroscopic investigations. CA (IC: 8.0 and 26.90 µg/mL) and SA (IC: 7.5 and 25.25 µg/mL) were identified to inhibit α-glucosidase and α-amylase in a competitive manner with low Ki values. In vitro glycation experiments further revealed that MJ and its components inhibited each stage of protein glycation as well as the generation of intermediate chemicals. Furthermore, CA (IC: 3.10) and SA (IC: 3.0 µg/mL) inhibited aldose reductase effectively in a non-competitive manner, respectively. The binding affinity of these substances towards the enzymes examined has been proposed by molecular docking and molecular dynamics simulation studies, which may explain their inhibitory activities. The found potential of MJ in antihyperglycaemic activity via inhibition of α-glucosidase and in antidiabetic action via inhibition of the polyol pathway and protein glycation is more likely to be related to the presence of the phenolic compounds, according to our findings.
Topics: Aldehyde Reductase; Artocarpus; Enzyme Inhibitors; Flour; Kinetics; Molecular Docking Simulation; Polyphenols; alpha-Amylases; alpha-Glucosidases
PubMed: 35335251
DOI: 10.3390/molecules27061888