Label-free electrochemical detection of singlet oxygen protein damage

V. VARGOVÁ; R.E. GIMÉNEZ; H. CERNOCKÁ; D. CHITO TRUJILLO; F. TULLI; V.I. PAZ ZANINI; E. PALECEK; C.D. BORSARELLI; V. OSTATNA

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

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

0013-4686

Oxidative damage of proteins results in changes on their structure and function. In this work, the singlet oxygen (1O2)?mediated oxidation of bovine serum albumin (BSA) and urease by blue-light photosensitization of the tris(2,2´-bipyridine) ruthenium (II) cation [Ru(bpy)3]2+ was studied by square wave voltammetry at glassy carbon electrode and by constant current chronopotentiometry at mercury electrode. Small changes in voltammetric oxidation Tyr and Trp peaks did not indicate significant changes in the BSA structure after photo-oxidation at carbon electrode. On the other hand chronopotentiometric peak H of BSA at HMDE increased during blue-light photosensitization, what indicated that photo-oxidized BSA was more susceptible to the electric field-induced denaturation than non-oxidized native BSA. Similar results were obtained for urease, where enzymatic activity was also evaluated. The present results show the capability of label- and reagent-free electrochemical methods to detect oxidative changes in protein, and we believe that they will become soon important tools for detection of various protein damages.