Role Of Protein Oxidation Research Articles

Pre-rigor salting improves gel strength and water-holding of surimi gel made from snakehead fish (Channa argus): The role of protein oxidation

The purpose of this study was to determine the effect of pre-rigor salting on the quality characteristics of surimi gels prepared from snakehead fish muscle. Pre-rigor and post-rigor muscle were mixed with 0.3% or 3% NaCl (w/w) and made into surimi gels, respectively. Results showed that pre-rigor muscle had a higher content of ATP, longer sarcomere, higher pH and greater protein solubility. Metabolic profile suggested that pre-rigor muscle had higher content (a 28-fold increase) of antioxidants such as butyryl-l-carnitine. Transmission electron microscopy showed more damage of mitochondria in post-rigor muscle. Surimi paste from pre-rigor meat chopped with 3% NaCl generally showed greater radical scavenging ability and had higher content of free sulfhydryl. Surimi gel made from pre-rigor muscle salted with 3% NaCl showed a larger gel strength (3.18 kg*mm vs. 2.22 kg*mm) and better water-holding (86% vs. 80%) than that of post-rigor group. Based on these findings, we hypothesized that: In addition to other factors such as pH, degree of denaturation, etc., less protein oxidation in pre-rigor salted surimi also contributes to the improved gel properties.

Are Methionine Sulfoxide-Containing Proteins Related to Seed Longevity? A Case Study of Arabidopsisthaliana Dry Mature Seeds Using Cyanogen Bromide Attack and Two-Dimensional-Diagonal Electrophoresis.

In recent years, several reports pointed out the role of protein oxidation in seed longevity, notably regarding the oxidation of methionine (Met) residues to methionine sulfoxide (MetO) in proteins. To further consider this question, we present a handy proteomic method based on the use of two-dimensional diagonal electrophoresis (2Dd) and cyanogen bromide (CNBr) cleavage, which we refer to as 2Dd-CNBr. CNBr treatment of proteins causes the non-enzymatic hydrolysis of peptide bonds on the carboxyl side of reduced Met residues. However, Met oxidation causes a lack of cleavage, thus modifying the electrophoretic mobility of CNBr-induced peptides. This approach was first validated using bovine serum albumin as a model protein, which confirmed the possibility of distinguishing between oxidized and non-oxidized forms of Met-containing peptides in gels. Then, the 2Dd-CNBr method was applied to the Arabidopsis thaliana seed protein extract in a control (non-oxidized) condition and in an oxidized one (as obtained following hypochlorous acid treatment). Twenty-four oxidized Met residues in 19 proteins identified by mass spectrometry were found to be surface exposed in these proteins. In the three-dimensional environment of the oxidized Met, we detected amino acid residues that could be converted by oxidation (carbonylation) or by phosphorylation, suggesting a possible interplay between Met oxidation and the other protein modifications. The identification of the proteins oxidatively modified in Met residues revealed the finding that MetO-containing proteins are related to seed longevity. Based on these results, we suggest that the method presently described also has the potential for wider applications.

The role of protein oxidation in the development of diabetic microvascular complications

OBJECTIVE:The role of protein oxidation in the development of diabetic microvascular complications was investigated.METHODS:In total, 266 participants were split into five groups: Group 1; diabetes mellitus for at least 10 years without any complications, Group 2; diabetic nephropathy, Group 3; diabetic neuropathy, Group 4; diabetic retinopathy, and Group 5; control group. Thiol, disulfide, ferroxidase, and ischemia-modified albumin (IMA) levels were analyzed in the serum.RESULTS:Native thiol, total thiol, and native thiol/total thiol were lower in Group 4 than Groups 1, 3, and 5 (p<0.001). However, disulfide/native thiol and disulfide/total thiol were higher in Group 4 than all other groups (p<0.001). IMA was higher in Groups 3 and 4 than all other groups (p<0.001). Ferroxidase was lower in Groups 3 and 4 than Group 2 (p<0.001).CONCLUSION:Thiol-disulfide homeostasis impairment in favor of disulfide may have a function in the progress of diabetic retinopathy. Furthermore, the disruptions of IMA and ferroxidase levels involve in the development of diabetic retinopathy and neuropathy.

Milk protein oxidation in healthy subjects: A preliminary study

The role of protein oxidation in the regulation of whole body protein metabolism is unknown. Previously, it was observed that vigorous exercise led to increased protein oxidation. To further characterise 13C-milk protein oxidation in healthy subjects, the oxidation of ingested 13C-protein after an overnight fast was measured using a non-invasive 13C-protein breath test. This approach enables the analysis of 13C-protein oxidation kinetics and the effect of interfering factors. It was found that the estimated maximal 13C-milk protein oxidation was 0.07 g min−1, corresponding to a theoretical maximal oxidation capacity of ≈1.4 g kg body weight−1 d−1. No indications were found for preferential oxidation of non-essential amino acids. Combined ingestion of 30 g 13C-whey protein with 30 g glucose resulted in a 19% decrease of 13C-whey protein oxidation. It was concluded that exogenous 13C-whey protein oxidation can be affected by other co-ingested nutrients like glucose.

A study on role of protein oxidation and lipid peroxidation as markers in NIDDM patients

A study on role of protein oxidation and lipid peroxidation as markers in NIDDM patients

Role of protein oxidation in the nutritional loss and texture changes in ready‐to‐eat chicken patties

SummaryThe oxidative damage to proteins during processing of ready‐to‐eat chicken patties and its impact on the nutritional value and texture properties of the product were assessed. The effect of cooking techniques (boiling, roasting and grilling) and microwave reheating (600 mW per 1 min) after 7 and 14 days of cold storage (+4 °C) were studied. Cooking methods had an effect (P &lt; 0.05) on most protein oxidation parameters, including protein depletion of tryptophan, thiols, protein carbonylation and formation of cross‐links. Overall, the succeeding chilled storage led to an aggravation of the oxidative damage which occurred along with hardness increase and impaired digestibility. Microwave reheating had contradictory effects on protein oxidation parameters. An increase in protein carbonylation occurred along with a cleavage of disulphide bonds that would explain a decrease in hardness. This study illustrates to which extent the oxidative damage to meat proteins affects protein quality and nutritional value of a severely processed meat product. The impact of assorted cooked procedures on these events is also discussed.

Oxidant/Antioxidant Balance in Animal Nutrition and Health: The Role of Protein Oxidation.

This review examines the role that oxidative stress (OS), and protein oxidation in particular, plays in nutrition, metabolism, and health of farm animals. The route by which redox homeostasis is involved in some important physiological functions and the implications of the impairment of oxidative status on animal health and diseases is also examined. Proteins have various and, at the same time, unique biological functions and their oxidation can result in structural changes and various functional modifications. Protein oxidation seems to be involved in pathological conditions, such as respiratory diseases and parasitic infection; however, some studies also suggest that protein oxidation plays a crucial role in the regulation of important physiological functions, such as reproduction, nutrition, metabolism, lactation, gut health, and neonatal physiology. As the characterization of the mechanisms by which OS may influence metabolism and health is attracting considerable scientific interest, the aim of this review is to present veterinary scientists and clinicians with various aspects of oxidative damage to proteins.

The association of FOXO3A gene polymorphisms with serum FOXO3A levels and oxidative stress markers in vitiligo patients

Vitiligo is an acquired epidermal pigment loss of the skin. Oxidative stress is one of the major theories in the pathophysiology of vitiligo. FOXO3A is the forkhead members of the class O (FOXO) transcription factors, and plays an important role in cell cycle regulation, apoptosis, oxidative stress, and DNA repair. The aim of our study was to investigate FOXO3A gene polymorphisms and FOXO3A protein levels, activities of superoxide dismutase (SOD) and catalase antioxidant enzymes in vitiligo patients and healthy controls. Moreover, the level of plasma advanced oxidation protein products (AOPP) in subjects was evaluated to understand the possible role of protein oxidation in disease etiology. Study groups included 82 vitiligo patients and 81 unrelated healthy controls. FOXO3A polymorphisms were determined using polymerase chain reaction–restriction fragment length polymorphism method. FOXO3A levels and catalase activity were measured by ELISA whereas AOPP levels and SOD activity was measured by spectrophotometric analysis. We found a significant relationship between rs4946936 polymorphism of FOXO3A gene and vitiligo/active vitiligo patients (p=0.017; p=0.019 respectively), but not for rs2253310 (p>0.05). SOD activity and AOPP levels of vitiligo patient were increased compared with control group, whereas FOXO3A levels and catalase enzyme activity of vitiligo patient were decreased compared with control group (p<0.05). Our study indicates that rs4946936 of FOXO3A gene may associate susceptibility of vitiligo, especially active vitiligo. Moreover, our results confirm that oxidative stress may play a role in the pathophysiology of vitiligo. Further studies with larger samples are required to elucidate the role of FOXO3A in vitiligo.

The association of Foxo3a gene polymorphisms with serum Foxo3a levels and oxidative stress markers in vitiligo patients

Vitiligo is an acquired epidermal pigment loss the skin with destruction of melanocytes. Oxidative stress is one of the major theories in the pathophysiology of vitiligo. FOXO3a is the forkhead members of the class O (FOXO) transcription factors, and plays important role in cell cycle regulation, apoptosis, oxidative stress, and DNA repair. The aim of our study was to investigate, for the first time, FOXO3a gene polymorphisms and FOXO3a protein levels, activities of superoxide dismutase (SOD) and catalase antioxidant enzymes in vitiligo patient and healthy controls. Moreover, plasma advanced oxidation protein products (AOPP) levels in subjects was evaluated to understand the possible role of protein oxidation in disease etiology. Studies groups included 82 vitiligo patients and 81 unrelated healthy controls. FOXO3a polymorphisms were determined using polymerase chain reaction-restriction fragment length polymorphism method. FOXO3a levels and catalase activity were measured by ELISA whereas AOPP levels and SOD activity were measured spectrophotometric analyses. We found a significant relationship between rs4946936 polymorphism of FOXO3a gene and vitiligo/active vitiligo patients (p=0.017; p=0.019 respectively), but not for rs2253310 (p>0.05). SOD activity and AOPP levels of vitiligo patient were increased compared with control group, whereas FOXO3a levels and catalase enzyme activity of vitiligo patient were decreased compared with control group (p<0.05). Our study indicates that rs4946936 of FOXO3a gene may associate susceptibility of vitiligo, especially active vitiligo. Moreover, our results confirm that oxidative stress may play a role in the pathophysiology of vitiligo. Further studies with larger samples are required to elucidate the role of FOXO3a in vitiligo.

Protein and Lipid Oxidation in Parma Ham during Production

Lipid oxidation adds to the characteristic flavor of dry-cured products, but the role of protein oxidation in the production of such meats is unknown. Lipid and protein oxidations in biceps femoris (BF) and semimembranosus (SM) muscles were evaluated throughout the production period of Parma ham (0-13 months). Lipid oxidation, determined as primary and secondary lipid oxidation products (POV and TBARS), and protein thiol loss commenced immediately without any lag phase and preceded the initiation of protein radicals and protein carbonyls, which increased after a lag phase of 3 months. TBARS reached a maximum value of 2.5 mg MDA/kg dry matter in SM after 1 month and leveled off at 1 mg MDA/kg dry matter in both SM and BF between 6 and 12 months. Loss in protein thiols proceeded similarly for SM and BF from initial ∼50 to ∼27 nmol/mg protein after 6 months and stayed constant. Gel electrophoresis showed that myosin was lost primarily by proteolytic degradation and not by polymerization through protein disulfides. Overall, oxidation accelerated during the first stages of production but stabilized toward the final stages of maturation.

The role of protein oxidation in the onset of the transthyretin amyloidoses

The transthyretin (TTR) amyloidoses are a subset of protein misfolding diseases characterized by the age‐dependent deposition of amyloid fibrils, derived from either wild type or mutant forms of the plasma protein TTR. Although it is clear that age is a major risk factor for the development of the TTR and other systemic amyloidoses, there are few studies addressing the molecular mechanisms responsible for the apparent effect of aging.There is a general increase in the concentrations of oxidation products of proteins, lipids and DNA associated with aging. We hypothesize that an increase in TTR oxidation with age predisposes to TTR aggregation in vivo. We have produced oxidized forms of wild‐type TTR similar to those reported to be present in human plasma. Chaotrope‐mediated denaturation/renaturation experiments showed that modified forms of TTR, including those with oxidized methionines and cysteines and those with carbonylated amino acids displayed reduced in vitro stability relative to native non‐oxidized TTR. The modified TTRs also had differential propensity for amyloid fibril formation with respect to native TTR. Sera from mice transgenic for a wild‐type human TTR gene show increased degrees of TTR carbonylation with aging. The greater proportion of circulating oxidized TTR seen in the older mice with its lower stability, may play a role in the development and onset of the senile wild type TTR associated amyloidosis. (This work is supported by 1R01AG032285 NIH/NIA)

Protein Oxidation and Lipid Peroxidation in Brain of Subjects with Alzheimer's Disease: Insights into Mechanism of Neurodegeneration from Redox Proteomics

Alzheimer's disease (AD), the leading cause of dementia, involves regionalized neuronal death, synaptic loss, and an accumulation of intraneuronal, neurofibrillary tangles and extracellular senile plaques. Although the initiating causes leading to AD are unknown, a number of previous studies reported the role of oxidative stress in AD brain. Postmortem analysis of AD brain showed elevated markers of oxidative stress including protein nitrotyrosine, carbonyls in proteins, lipid oxidation products, and oxidized DNA bases. In this review, we focus our attention on the role of protein oxidation and lipid peroxidation in the pathogenesis of AD. Particular attention is given to the current knowledge about the redox proteomics identification of oxidatively modified proteins in AD brain.

Regulation of MAP kinase-dependent apoptotic pathway: implication of reactive oxygen and nitrogen species

Mitogen-activated protein (MAP) kinase signaling cascades are multi-functional signaling networks that influence cell growth, differentiation, apoptosis, and cellular responses to stress. Apoptosis signal-regulating kinase 1 (ASK1) is a MAP kinase kinase kinase that triggers apoptogenic kinase cascade leading to the phosphorylation/activation of c-Jun N-terminal kinases and p38-MAP kinase, which are responsible for inducing apoptotic cell death. This pathway plays a pivotal role in transduction of signals from different apoptotic stimuli. In the present review, we summarized the recent evidence concerning MAP kinase-dependent apoptotic pathway and its regulation in the mammalian cells and organism in vivo. We have shown that the key messengers of regulation of this pathway are the reactive oxygen and nitrogen species. The role of protein oxidation and S-nitrosation in induction of apoptotic cell death via ASK1 is discussed. Also we have outlined other recently discovered signal transduction processes involved in the regulation of ASK1 activity and downstream pathway.

Apoptosis versus cytoproliferation in hepatocellular carcinoma: role of protein oxidation

Apoptosis versus cytoproliferation in hepatocellular carcinoma: role of protein oxidation

Apoptosis versus cytoproliferation in hepatocellular carcinoma: role of protein oxidation

Apoptosis versus cytoproliferation in hepatocellular carcinoma: role of protein oxidation

Differential oxidation of apolipoprotein E isoforms and interaction with phospholipids

Accumulation of oxidized proteins has been demonstrated in the brain of patients suffering from Alzheimer’s disease (AD). Among the proteins found in cerebral amyloid deposits, apolipoprotein (apo) E is a polymorphic protein which one specific isoform, apo E4, has been widely associated with AD. Apo E may be linked with AD by its isoform-specific interaction with lipids or other proteins in amyloid plaques. Using the myeloperoxidase oxidative system, we report that oxidation of the three recombinant apo E isoforms is differential (as estimated using immunoblot and high-performance liquid chromatography analysis), with apo E4 being more susceptible than apo E3, which in turn is much more susceptible than apo E2. In addition, susceptibility to thrombin proteolysis is reduced when apo E is oxidized, and oxidation of apo E decreases its incorporation into phospholipid discs by approximately 50%. Oxidation of apo E may contribute to inefficient lipid recycling in the brain, particularly regarding apo E4 and E3. Our results link and strengthen both the ϵ4 allele linkage with AD and the role of protein oxidation in AD. The cerebral mechanisms underlying apo E oxidation and/or myeloperoxidase functions in vivo remain to be assessed.

Effects of training on respiratory gas exchange, nitrogenous waste excretion, and fuel usage during aerobic swimming in juvenile rainbow trout (Oncorhynchus mykiss)

Fuel utilization during aerobic exercise was determined in juvenile rainbow trout that had previously undergone 2 weeks of continuous aerobic training at 25% of their maximum sustainable speed (Ucrit) and was compared with that in untrained trout. Instantaneous fuel usage was calculated from simultaneous measurements of oxygen consumption ( MO2), carbon dioxide excretion ( MCO2), and nitrogenous waste excretion (MN). Over 58 h of sustained aerobic exercise at 55% of Ucrit, MO2and MCO2remained virtually constant in the trained fish, in contrast to the significant fall over time in untrained fish, but total gas exchange was similar in the two groups. Aerobic respiratory quotient remained constant in the two treatments. MNwas lower in the trained fish, resulting in a much lower (and stable) nitrogen quotient; the nitrogen quotient increased with swimming duration in the untrained fish. Lipid was the major fuel source powering aerobic exercise in both groups. Carbohydrate also played a significant role, whereas protein was of lowest quantitative importance. Training resulted in a decrease in reliance on protein and an increase in reliance on lipid metabolism. The role of protein oxidation in supporting aerobic swimming in fish, which is smaller than commonly believed, is further reduced by training.