Spontaneous Oxidation of Methionine: Effect on the Quantification of Plasma Methionine Levels

Potgieter, H. C.; Ubbink, Johan B.; Bissbort, S.; Bester, Megan Jean; Spies, J. H.; Vermaak, W. J. H.

doi:10.1006/abio.1997.2075

Cited by 39 publications

(23 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…since both the control and the patient samples were treated in the same manner, and this process is known to be modulated by plasma proteins (35). Even if selective artifactual oxidation of Met to MetSO was occurring in the SLE patient samples, the decrease in total levels of Met plus MetSO and the increased loss seen with increased disease activity are still consistent with an enhanced level of oxidative stress in the SLE patients.…”

Section: Discussionmentioning

confidence: 84%

Increased levels of serum protein oxidation and correlation with disease activity in systemic lupus erythematosus

Morgan¹,

Sturgess²,

Davies³

2005

Arthritis & Rheumatism

121

View full text Add to dashboard Cite

Objective. To examine protein oxidation in systemic lupus erythematosus (SLE) and to correlate levels of protein oxidation products with disease activity.Methods. Serum was collected from SLE patients and healthy control subjects. Protein-bound carbonyls and the pro-oxidant enzyme myeloperoxidase (MPO) were quantified by enzyme-linked immunosorbent assay. Protein thiols were quantified using 5,5-dithionitrobenzoic acid. Protein-bound amino acids and methionine, tyrosine, and phenylalanine oxidation products were quantified by acid hydrolysis and highperformance liquid chromatography. Disease activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Levels of antidouble-stranded DNA (anti-dsDNA) antibodies were measured by radioimmunoassay.Results. Compared with control subjects, SLE patients exhibited elevated levels of protein carbonyls (0.108 ؎ 0.078 versus 0.064 ؎ 0.028 nmoles/mg of protein; P ‫؍‬ 0.046), decreased levels of protein thiols (3.9 ؎ 1.1 versus 4.9 ؎ 0.7 nmoles/mg of protein; P ‫؍‬ 0.003), decreased levels of protein-bound methionine (P ‫؍‬ 0.0007), and increased levels of protein-bound methionine sulfoxide (P ‫؍‬ 0.0043) and 3-nitrotyrosine (P ‫؍‬ 0.0477). SLE patients with high SLEDAI scores or elevated anti-dsDNA antibody levels exhibited increased oxidation compared with patients with low SLEDAI scores or low antibody levels. Serum MPO levels were decreased in SLE patients (P ‫؍‬ 0.03), suggesting that this enzyme is not responsible for the enhanced protein oxidation.Conclusion. We found elevated levels of multiple markers of protein oxidation in sera from SLE patients compared with controls, and these levels correlated with disease activity. The findings suggest that protein oxidation may play a role in the pathogenesis of chronic organ damage in SLE.

show abstract

Section: Discussionmentioning

confidence: 84%

Increased levels of serum protein oxidation and correlation with disease activity in systemic lupus erythematosus

Morgan¹,

Sturgess²,

Davies³

2005

Arthritis & Rheumatism

121

View full text Add to dashboard Cite

show abstract

“…There is a widespread anecdotal belief that Met oxidation in proteins is an artifact of sample preparation (Potgieter et al 1997). However, the position of MetSO in proteins has a preference for neighboring polar residues indicating a nonrandom pattern (Ghesquière et al 2011).…”

Section: Met Oxidation Is Commonmentioning

confidence: 99%

Convergent signaling pathways—interaction between methionine oxidation and serine/threonine/tyrosine O-phosphorylation

Rao

Thelen

Miernyk

2015

Cell Stress and Chaperones

View full text Add to dashboard Cite

Oxidation of methionine (Met) to Met sulfoxide (MetSO) is a frequently found reversible posttranslational modification. It has been presumed that the major functional role for oxidation-labile Met residues is to protect proteins/ cells from oxidative stress. However, Met oxidation has been established as a key mechanism for direct regulation of a wide range of protein functions and cellular processes. Furthermore, recent reports suggest an interaction between Met oxidation and O-phosphorylation. Such interactions are a potentially direct interface between redox sensing and signaling, and cellular protein kinase/phosphatase-based signaling. Herein, we describe the current state of Met oxidation research, provide some mechanistic insight into crosstalk between these two major posttranslational modifications, and consider the evolutionary significance and regulatory potential of this crosstalk.

show abstract

“…The concentration of ONOO -used in our experiments (100 µM) corresponds to the concentrations reported to occur in vivo, when the production of NO · and O 2 ·-is locally elevated (inflammation, oxidative stress, ischaemia and reperfusion) [19][20][21]. The concentration of H 2 O 2 (2 mM) has been chosen on the base of the available data on the range of H 2 O 2 concentrations used in various bioassays and our previous laboratory protocols [22][23][24].…”

Section: Methodsmentioning

confidence: 99%

Red cabbage anthocyanins may protect blood plasma proteins and lipids

et al. 2011

View full text Add to dashboard Cite

The present in vitro study was designed to examine the antioxidative activity of red cabbage anthocyanins (ATH) in the protection of blood plasma proteins and lipids against damage induced by oxidative stress. Fresh leaves of red cabbage were extracted with a mixture of methanol/distilled water/0.01% HCl (MeOH/H2O/HCl, 50/50/1, v/v/w). Total ATH concentration [µM] was determined with cyanidin 3-glucoside as a standard. Phenolic profiles in the crude red cabbage extract were determined using the HPLC method. Plasma samples were exposed to 100 µM peroxynitrite (ONOO−) or 2 mM hydrogen peroxide (H2O2) in the presence/absence of ATH extract (5–15 µM); oxidative alterations were then assessed. Pre-incubation of plasma with ATH extract partly reduced oxidative stress in plasma proteins and lipids. Dose-dependent reduction of both ONOO− and H2O2-mediated plasma protein carbonylation was observed. ATH extract partly inhibited the nitrative action of ONOO−, and significantly decreased plasma lipid peroxidation caused by ONOO− or H2O2. Our results demonstrate that anthocyanins present in red cabbage have inhibitory effects on ONOO− and H2O2-induced oxidative stress in blood plasma components. We suggest that red cabbage ATH, as dietary antioxidants, should be considered as potentially usable nutraceuticals in the prevention of oxidative stress-related diseases.

show abstract

Spontaneous Oxidation of Methionine: Effect on the Quantification of Plasma Methionine Levels

Cited by 39 publications

References 38 publications

Increased levels of serum protein oxidation and correlation with disease activity in systemic lupus erythematosus

Increased levels of serum protein oxidation and correlation with disease activity in systemic lupus erythematosus

Convergent signaling pathways—interaction between methionine oxidation and serine/threonine/tyrosine O-phosphorylation

Red cabbage anthocyanins may protect blood plasma proteins and lipids

Contact Info

Product

Resources

About