Structure-guided identification of function: role of Capsicum annuum vicilin during oxidative stress

2018 ◽  
Vol 475 (19) ◽  
pp. 3057-3071 ◽  
Author(s):  
Meha Shikhi ◽  
Deepak T. Nair ◽  
Dinakar M. Salunke
Keyword(s):  
Oxidative Stress ◽  
Crystal Structure ◽  
Superoxide Dismutase ◽  
Salicylic Acid ◽  
Capsicum Annuum ◽  
Superoxide Dismutase Activity ◽  
Size Exclusion ◽  
Spectrometric Analysis ◽  
Physiological Functions ◽  
Cupin Superfamily

Proteins belonging to cupin superfamily are known to have critical and diverse physiological functions. However, 7S globulins family, which is also a part of cupin superfamily, were undermined as only seed storage proteins. Structure determination of native protein — Vic_CAPAN from Capsicum annuum — was carried out, and its physiological functions were explored after purifying the protein by ammonium sulfate precipitation followed by size exclusion chromatography. The crystal structure of vicilin determined at 2.16 Å resolution revealed two monomers per asymmetric unit which are juxtaposed orthogonal with each other. Vic_CAPAN consists predominately of β-sheets that folds to form a β-barrel structure commonly called cupin fold. Each monomer of Vic_CAPAN consists of two cupin fold domains, N-terminal and C-terminal, which accommodate two different ligands. A bound ligand was identified at the C-terminal cupin fold in the site presumably conserved for metabolites in the crystal structure. The ligand was confirmed to be salicylic acid through mass spectrometric analysis. A copper-binding site was further observed near the conserved ligand-binding pocket, suggesting possible superoxide dismutase activity of Vic_CAPAN which was subsequently confirmed biochemically. Vicilins from other sources did not exhibit this activity indicating functional specificity of Vic_CAPAN. Discovery of bound salicylic acid, which is a known regulator of antioxidant pathway, and revelation of superoxide dismutase activity suggest that Vic_CAPAN has an important role during oxidative stress. As salicylic acid changes the redox state of cell, it may act as a downstream signal for various pathways involved in plant biotic and abiotic stress rescue.

Diazoxide Modulates Cardiac Hypertrophy by Targeting H2O2 Generation and Mitochondrial Superoxide Dismutase Activity

2020 ◽  
Vol 13 (1) ◽  
pp. 76-83
Author(s):  
Aline Maria Brito Lucas ◽  
Joana Varlla de Lacerda Alexandre ◽  
Maria Thalyne Silva Araújo ◽  
Cicera Edna Barbosa David ◽  
Yuana Ivia Ponte Viana ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Cardiac Hypertrophy ◽  
Superoxide Dismutase Activity ◽  
Heart Weight ◽  
Pharmacological Intervention ◽  
Wall Thickening ◽  
H2o2 Production ◽  
Mitochondrial Superoxide ◽  
Mitochondrial Superoxide Dismutase

Background: Cardiac hypertrophy involves marked wall thickening or chamber enlargement. If sustained, this condition will lead to dysfunctional mitochondria and oxidative stress. Mitochondria have ATP-sensitive K+ channels (mitoKATP) in the inner membrane that modulate the redox status of the cell. Objective: We investigated the in vivo effects of mitoKATP opening on oxidative stress in isoproterenol- induced cardiac hypertrophy. Methods: Cardiac hypertrophy was induced in Swiss mice treated intraperitoneally with isoproterenol (ISO - 30 mg/kg/day) for 8 days. From day 4, diazoxide (DZX - 5 mg/kg/day) was used in order to open mitoKATP (a clinically relevant therapy scheme) and 5-hydroxydecanoate (5HD - 5 mg/kg/day) or glibenclamide (GLI - 3 mg/kg/day) were used as mitoKATP blockers. Results: Isoproterenol-treated mice had elevated heart weight/tibia length ratios (HW/TL). Additionally, hypertrophic hearts had elevated levels of carbonylated proteins and Thiobarbituric Acid Reactive Substances (TBARS), markers of protein and lipid oxidation. In contrast, mitoKATP opening with DZX avoided ISO effects on gross hypertrophic markers (HW/TL), carbonylated proteins and TBARS, in a manner reversed by 5HD and GLI. Moreover, DZX improved mitochondrial superoxide dismutase activity. This effect was also blocked by 5HD and GLI. Additionally, ex vivo treatment of isoproterenol- induced hypertrophic cardiac tissue with DZX decreased H2O2 production in a manner sensitive to 5HD, indicating that this drug also acutely avoids oxidative stress. Conclusion: Our results suggest that diazoxide blocks oxidative stress and reverses cardiac hypertrophy. This pharmacological intervention could be a potential therapeutic strategy to prevent oxidative stress associated with cardiac hypertrophy.

Crystal Structure and Superoxide Dismutase Activity of [Cu(Imidazole)2(Quinoline)Cl2]·0.5[Cu(Imidazole)4Cl2]

2002 ◽  
Vol 55 (12) ◽  
pp. 1433-1439 ◽  
Author(s):  
J.R. Anacona ◽  
Carmen Gutierrez ◽  
Osmar Nusetti ◽  
Daniel LoroÑo
Keyword(s):  
Crystal Structure ◽  
Superoxide Dismutase ◽  
Superoxide Dismutase Activity

scholarly journals P1143REDOX PROFILING IN MESOTHELIAL CELLS IN EXPERIMENTAL PERITONEAL DIALYSIS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Rebecca Herzog ◽  
Anja Wagner ◽  
Klaus Kratochwill
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Fluorescent Dyes ◽  
Mesothelial Cells ◽  
Superoxide Dismutase Activity ◽  
Cysteine Oxidation ◽  
Redox Stress ◽  
Redox Proteomics ◽  
Intracellular Ros ◽  
The Impact

Abstract Background and Aims PD-fluids lead to generation of reactive oxygen species (ROS) in the peritoneal cavity. The caused oxidative stress, defined as a cellular oxidant-antioxidant imbalance impairs not only peritoneal cell viability but also contributes to progression of local and systemic PD-related pathomechanisms. We aim to analyze the impact and specific targets of ROS during PD and the anti-oxidative mechanism of supplementation of PD-fluid with alanyl-glutamine (AlaGln) on a global proteome-wide level. Method To establish a redox-proteomics workflow for studying oxidative stress in peritoneal mesothelial cells we used a gold-standard model of redox-stress (H2O2) and PD-fluid induced stress. Levels of oxidative stress were first validated by increased intracellular ROS and superoxide dismutase activity with PD-fluid and H2O2 treatment and a reduction of these parameters by the addition of AlaGln. To detect alterations of the redox proteome, cysteine residues were either directly or indirectly labeled with fluorescent dyes (redox-2D-DiGE) or isobaric tags (iodo-TMT). Results: The gel-based approach allowed global visualization of the reduced and oxidized cysteines and revealed redox profiles of 540 protein spots. Compared to control, we found an increase in oxidized and decrease in reduced cysteines in all PD treatments. The development of a highly sensitive LC/MS-based redox proteomics workflow allowed identification of ∼950 proteins affected by redox-stress in mesothelial cells and confirmed the quantitative levels seen on cysteine oxidation. The addition of AlaGln reduced the overall redox status (intracellular ROS and superoxide dismutase activity) but further showed different proteins to be affected by redox modifications. Conclusion: Redox proteomics of peritoneal cells could represent a novel approach for the identification of mediators of PD-induced pathomechanisms, but also to evaluate effects of novel anti-oxidant therapeutical or pharmacological interventions.

Activity of erythrocyte antioxidant enzymes in healthy women depends on age, BMI, physical activity and diet

2020 ◽  
Author(s):  
Elżbieta Cecerska-Heryć ◽  
Klaudia Krauze ◽  
Angelika Szczęśniak ◽  
Aleksandra Goryniak Mikołajczyk ◽  
Natalia Serwin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Physical Activity ◽  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Antioxidant Enzymes ◽  
Catalase Activity ◽  
Smoking Status ◽  
Superoxide Dismutase Activity ◽  
Antioxidant Systems ◽  
Healthy Women

Abstract Introduction Antioxidant enzymes protect the human body against the harmful effects of oxidative stress. The activity of antioxidant enzymes changes with age, and depends on dietary nutrients such as fats and vitamins, which can have a significant impact on minimizing or exacerbating oxidative stress. Aim Examine the effect of age, BMI, diet, physical activity and smoking status on the activity of erythrocyte antioxidant enzymes catalase, glutathione reductase, glutathione peroxidase glutathione S-transferase, superoxide dismutase and glutathione concentrations in healthy women. Material and methods This study included 98 healthy women aged between 20 and 65 years. All women underwent anthropometric tests: body weight, height, hip and waist circumference. Antioxidant activity in erythrocytes was measured by spectrophotometric methods. Results Catalase activity increased significantly with age (p<0.001), while superoxide dismutase activities and glutathione decreased with age (p =0.008, p =0.023, respectively). Women with a lower BMI (emaciation) had higher superoxide dismutase activity than those in the first degree of obesity (p = 0.009 Conclusions 1. Increased catalase activity with age may be a sign of a large amount of hydrogen peroxide, resulting from poorly functioning antioxidant systems in older age. 2. Decreased superoxide dismutase activity with age may indicate inactivation of this enzyme by excessive hydrogen peroxide, as well as glycation of superoxide dismutase molecules or reactions with lipid peroxidation products, the intensity of which increases with age. 3. The negative correlation between superoxide dismutase activity and BMI index indicates reduced enzymatic activity in obese subjects, despite increased ROS production by adipose tissue.

Sign in / Sign up

Export Citation Format

Share Document