Label-free electrochemical detection of singlet oxygen protein damage

VERONIKA VERGOVÁ; RODRIGO E. GIMENEZ; HANA CERNOCKA; DIANA CHITO TRUJILLO; FIORELLA TULLI; VERONICA I. PAZ ZANINI; EMIL PALECEK; CLAUDIO D. BORSARELLI; VERONIKA OSTATNÁ

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2016 vol. 187 p. 662 - 669

0013-4686

Oxidative damage of proteins results in changes of their structures and functions. In this work, the singletoxygen (1O2)-mediated oxidation of bovine serum albumin (BSA) and urease by blue-lightphotosensitization of the tris(2,20-bipyridine)ruthenium(II) cation [Ru(bpy)3]2+ was studied by squarewave voltammetry at glassy carbon electrode and by constant current chronopotentiometry at mercuryelectrode. Small changes in voltammetric oxidation Tyr and Trp peaks did not indicate significant changesin the BSA structure after photo-oxidation at carbon electrode. On the other hand chronopotentiometricpeak H of BSA at HMDE increased during blue-light photosensitization, indicating that photo-oxidizedBSA was more susceptible to the electricfield-induced denaturation than non-oxidized native BSA.Similar results were obtained for urease, where enzymatic activity was also evaluated. The presentresults show the capability of label- and reagent-free electrochemical methods to detect oxidativechanges in proteins. We believe that these methods will become important tools for detection of variousprotein damages.