o:25997 Albumin at the intersection between antioxidant and pro-oxidant in patients on peritoneal dialysis Albumin na raskrsnici izmedju antioksidanta i pro-oksidanta kod pacijenata na peritoneumskoj dijalizi en ABSTRACT Albumin (HSA) is a multifunctional protein and due to its free Cys34 thiol group, represents a main source of free thiols in the circulation. This property of HSA, combined with its ability to sequester redox active Cu(II) ions, makes HSA a dominant circulatory antioxidant. End stage kidney disease (ESRD) is a condition accompanied by elevated oxidative stress. The aim of the present study was to examine changes in the antioxidative capacity of HSA and Cu(II) binding affinity in patients on peritoneal dialysis (PD), and relate it to the Cys34 thiol group content and other structural changes of this molecule. HSA molecules are modified in ESRD patients subjected to PD, having significantly lower thiol group and bound Cu(II) content, reduced antioxidant capacity, an increased content of advanced glycation end-products and altered conformation. Also, Cu(II) binding capacity of HSA in these patients is impaired, since a significant portion of the high-affinity metal-binding site is unable to interact with Cu(II). Taking into account that the concentration of Cu(II) in the circulation of ESRD patients is much higher than in healthy persons and that Cu(II) binding capacity of HSA in these patients is significantly impaired, HSA may be considered as a novel circulatory pro-oxidant, thus exacerbating oxidative stress. Sažetak end stage renal disease, peritoneal dialysis, albumin, copper, thiols, antioxidative capacity 1552099 10.1016/j.freeradbiomed.2022.05.019 2022-06-09T17:08:17.667Z 44 yes 46 Marko Baralić University of Belgrade, School of Medicine, Serbia Ana Penezić University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia doktor biohemijskih nauka person 0000-0002-2539-4507 Olgica Nedić University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia doktor biohemijskih nauka person 0000-0003-2042-0056 Nikola Gligorijević University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia doktor biohemijskih nauka person 0000-0002-8691-2486 Zorana Dobrijević University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia doktor bioloških nauka person 0000-0002-4652-7719 Dragana Robajac University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia doktor biohemijskih nauka person 0000-0002-6423-4645 Miloš Šunderić University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia doktor biohemijskih nauka person 0000-0002-0940-9481 Goran Miljuš University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia doktor biohemijskih nauka person 0000-0001-6417-8711 Ivan Spasojević University of Belgrade, Institute for Multidisciplinary Research, Serbia person application/pdf 104195 https://phaidrabg.bg.ac.rs/o:25997 no yes 1 70 92000001 11A32 11A27 11A29 11A2905 Free Radical Biology and Medicine 187 105 112 Elsevier 2022