{"title":"Initiating redox reactions by ionizing radiation: A versatile, selective and quantitative tool","authors":"Peter Wardman","doi":"10.1016/j.rbc.2023.100004","DOIUrl":"https://doi.org/10.1016/j.rbc.2023.100004","url":null,"abstract":"<div><p>The absorption of ionizing radiation initiates redox reactions, producing chemical species resulting from single electron loss or electron gain. Radiation chemists have developed methods to study individual redox species selectively and to monitor their reactions in real time. This has provided an enormous resource of kinetic, thermodynamic and spectroscopic information concerning the characteristics and reactions of free radicals and their redox reactions, mainly in aqueous solution. While the techniques are specialized and exploiting them is certainly more difficult than initiating redox changes by simple mixing of two chemicals or adding a reagent to a biological target, it is useful to gain an understanding of the basic mechanisms and approaches involved in exploiting radiation chemistry in the wider context of redox reactions in biochemistry, chemistry, and biology. This should enable readers both to appreciate the reliance which can be placed on the kinetic and other information resulting from such studies, as well as identify potential new applications of the technique which might be exploited in their research, by seeking partners who have access to the necessary specialized equipment or just basic irradiation facilities. This review outlines how radiation can be used to initiate selective redox reactions, mainly in water, and helps point readers to resources which should be useful in considering such reactions in a wider context.</p></div>","PeriodicalId":101065,"journal":{"name":"Redox Biochemistry and Chemistry","volume":"5 ","pages":"Article 100004"},"PeriodicalIF":0.0,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49726688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"In Memoriam: Emeritus Professor Robin L. Willson","authors":"","doi":"10.1016/j.rbc.2022.100001","DOIUrl":"https://doi.org/10.1016/j.rbc.2022.100001","url":null,"abstract":"","PeriodicalId":101065,"journal":{"name":"Redox Biochemistry and Chemistry","volume":"1 ","pages":"Article 100001"},"PeriodicalIF":0.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49724544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicholas J. Magon, Rufus Turner, Anthony J. Kettle, Christine C. Winterbourn
{"title":"Cross-linking between cysteine and lysine, tryptophan or tyrosine in peptides and proteins treated with hypochlorous acid and other reactive halogens","authors":"Nicholas J. Magon, Rufus Turner, Anthony J. Kettle, Christine C. Winterbourn","doi":"10.1016/j.rbc.2023.100002","DOIUrl":"https://doi.org/10.1016/j.rbc.2023.100002","url":null,"abstract":"<div><p>Cysteine residues are the most favored targets for oxidation by hypochlorous acid and other reactive halogen species. The end-products of cysteine oxidation are usually considered to be reversibly formed disulfides and the more highly oxidized sulfinic and sulfonic acids. However, reactive halogen species are capable of generating additional products in which cysteine is cross-linked to other amino acids. Here we have treated a range of peptides with hypochlorous acid (HOCl) and hypobromous acid (HOBr), and used mass spectrometry to demonstrate sulfenamide, sulfinamide and sulfonamide formation with lysine residues, as well as –S(O)- and –S(O<sub>2</sub>)- linkages with tyrosine, tryptophan and arginine residues. The -(SO<sub>2</sub>)- products were more prevalent with HOCl than HOBr, reflecting its higher oxidizing ability. There was also considerable variation between peptides in efficiency of cross-linking compared with other modifications. The –S(O)- and –S(O<sub>2</sub>)- forms were much more resistant than the disulfide to reduction by dithiothreitol. Using calprotectin as a representative cysteine-containing protein, we show that a range of products containing each of these cross-links is formed when the protein is treated with HOCl. Two of the identified cysteine-lysine calprotectin cross-links were also detected in bronchoalveolar lavage fluid from children with cystic fibrosis. Our results imply that cross-linked species would be formed when cysteine-containing proteins are exposed to reactive halogen species, with the nature of the specific products depending on structural features around the cysteine residue. Cross-linking could have a modulatory effect on protein function or be detrimental in causing oligomerization and aggregation.</p></div>","PeriodicalId":101065,"journal":{"name":"Redox Biochemistry and Chemistry","volume":"1 ","pages":"Article 100002"},"PeriodicalIF":0.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49737345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}