Usage Information

Oxidation of Methionine by Human Polymorphonuclear Leukocytes
Min-Fu Tsan, Jasmine W. Chen
Min-Fu Tsan, Jasmine W. Chen
Published May 1, 1980
Citation Information: J Clin Invest. 1980;65(5):1041-1050. https://doi.org/10.1172/JCI109756.
View: Text | PDF
Research Article Article has an altmetric score of 3

Oxidation of Methionine by Human Polymorphonuclear Leukocytes

Abstract

Studies of the photosensitized oxidation have demonstrated that photodynamic oxidation of methionine is mediated by singlet oxygen (1O2). In this study, we demonstrated that phagocytosing human polymorphonuclear leukocytes (PMN), but not resting PMN, oxidized both intracellular and extracellular methionine to methionine sulfoxide. N-ethylmaleimide, which inhibits phagocytosis and cellular metabolism, inhibited the oxidation of methionine. Neutrophils from patients with chronic granulomatous disease did not oxidize methionine even in the presence of phagocytosis. The oxidation of methionine by phagocytosing normal PMN was inhibited by 1O2 quenchers, (1.4-diazabicyclo-[2,2,2]-octane, tryptophan, NaN3), myeloperoxidase (MPO) inhibitors (NaN3, KCN) and catalase. In contrast, superoxide dismutase, ethanol, and mannitol had no effect. Furthermore, 1O2 quenchers did not interfere with the production of superoxide (O2−) by phagocytosing PMN. The combination of catalase and SOD did not enhance the inhibition of methionine by phagocytosing PMN. On the other hand, deuterium oxide stimulated the oxidation of methionine by PMN almost 200%.

Authors

Min-Fu Tsan, Jasmine W. Chen

×

Usage data is cumulative from June 2024 through June 2025.

Usage JCI PMC
Text version 92 0
PDF 40 12
Scanned page 329 2
Citation downloads 39 0
Totals 500 14
Total Views 514
(Click and drag on plot area to zoom in. Click legend items above to toggle)

Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.

Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.

Advertisement