Detection, identification, and quantification of oxidative protein modifications

Abstract

Edited by Ruma Banerjee Exposure of biological molecules to oxidants is inevitable and therefore commonplace. Oxidative stress in cells arises from both external agents and endogenous processes that generate reactive species, either purposely (e.g. during pathogen killing or enzymatic reactions) or accidentally (e.g. exposure to radiation, pollutants, drugs, or chemicals). As proteins are highly abundant and react rapidly with many oxidants, they are highly susceptible to, and major targets of, oxidative damage. This can result in changes to protein structure, function, and turnover and to loss or (occasional) gain of activity. Accumulation of oxidatively-modified proteins, due to either increased generation or decreased removal, has been associated with both aging and multiple diseases. Different oxidants generate a broad, and sometimes characteristic, spectrum of post-translational modifications. The kinetics (rates) of damage formation also vary dramatically. There is a pressing need for reliable and robust methods that can detect, identify, and quantify the products formed on amino acids, peptides, and proteins, especially in complex systems. This review summarizes several advances in our understanding of this complex chemistry and highlights methods that are available to detect oxidative modifications-at the amino acid, peptide, or protein level-and their nature, quantity, and position within a peptide sequence. Although considerable progress has been made in the development and application of new techniques, it is clear that further development is required to fully assess the relative importance of protein oxidation and to determine whether an oxidation is a cause, or merely a consequence, of injurious processes.

The Imbalance among Oxidative Biomarkers and Antioxidant Defense Systems in Thromboangiitis Obliterans (Winiwarter-Buerger Disease)

“…Since MDA levels were unexpectedly low in TAO patients, we also evaluated the protein oxidation profile, analyzing the blood levels of protein carbonyl (PC), which has been demonstrated as a marker of protein oxidation [68]. Our results appear in agreement with the literature evidence showing that oxidizing species derived from the activity of myeloperoxidase (MPO) may lead to the formation of carbonyl groups in proteins with less modification in lipids [69].…”

Oxidative Stress: A Unifying Paradigm in Hypertension

“…27 ROS influence cell function by modifying proteins through posttranslational modifications, such as oxidation (sulfenylation, nitrosylation, glutathionylation, and carbomylation) and phosphorylation. [28][29][30] Proteins that are redox sensitive include ion transporters, receptors, signalling molecules, transcription factors, cytoskeletal structural proteins, and matrix metalloproteases, all of which are involved in regulating vascular, cardiac, and renal functions. 30,31 ROS are key signalling molecules through which vasoactive agents such as angiotensin II (Ang II), endothelin-1 (ET-1), aldosterone, and prostanoids mediate cellular effects, and they regulate intracellular calcium homeostasis, [32][33][34][35] which is important in triggering and maintaining vasoconstriction and cardiac contraction.…”

Tracking isotopically labeled oxidants using boronate-based redox probes

“…Both superoxide and H2O2 are relatively slow reacting and/or weak oxidants (4-6) but in biological systems can be converted to more reactive species ( Fig. 1), including peroxynitrite (7,8), peroxymonocarbonate (HCO4 -) (9,10), or hypochlorous acid (HOCl) (11), resulting in enhanced redox signaling and/or damage to cell components (5,12,13). Due to the short lifetime of most ROS in biological settings, detection and quantitative analyses of those species have remained a challenge, and development of new probes for redox biology is an active area of research.…”