title: Nitroxides prevent protein glycoxidation in vitro.
abstract: Seven nitroxides of different structures were studied for the ability to prevent glycoxidation of bovine serum albumin incubated with three monosaccharides (glucose, fructose, and ribose). Glycoxidation was estimated by fluorimetric parameters of protein modifications (formation of advanced glycation end products [AGEs], dityrosine, N'-formylkynurenine, and kynurenine) and enzyme-linked immunosorbent assay for AGEs. From among the nitroxides tested, (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), 4-carboxy-TEMPO, and 4-hydroxy-TEMPO offered significant protection against glycoxidation induced by glucose and fructose, while 3-carbamoyl-PROXYL was not protective, enhancing glycoxidation. Lower protection was observed for glycoxidation induced by ribose where only 3-carbamoyl-PROXYL and 4-amino-TEMPO showed some protection. Loss of electron spin resonance signal of the nitroxides was observed during glycoxidation indicating occurrence of free radical reactions in this process. These results suggest for the first time that nitroxides may be promising compounds for preventing glycoxidation.
authors.affiliation: Department of Biochemistry and Cell Biology, University of Rzeszów , Rzeszów , Poland.
authors.forename: I
authors.initials: I
authors.lastname: Sadowska-Bartosz
authors.forename: S
authors.initials: S
authors.lastname: Galiniak
authors.forename: J
authors.initials: J
authors.lastname: Skolimowski
authors.forename: I
authors.initials: I
authors.lastname: Stefaniuk
authors.forename: G
authors.initials: G
authors.lastname: Bartosz
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D003497:Cyclic N-Oxides / Q000494:pharmacology*; D005632:Fructose / Q000737:chemistry; D005947:Glucose / Q000737:chemistry; D006031:Glycosylation / Q000187:drug effects; D009005:Monosaccharides / Q000737:chemistry*; D010084:Oxidation-Reduction / Q000187:drug effects; D062106:Protein Degradation End Products / Q000032:analysis*; D012266:Ribose / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D000975:Antioxidants; D003497:Cyclic N-Oxides; D009005:Monosaccharides; D062106:Protein Degradation End Products; D012710:Serum Albumin, Bovine; D005632:Fructose; D012266:Ribose; D005947:Glucose
keywords: albumin; fructose; glucose; glycoxidation; nitroxides; ribose