Complexos de Dopamina com Albumina como modelo para etiquetagem eletroquímica de proteínas desprovidas de centros redox metálicos

Abstract

A very simple strategy for studying electrochemical properties for any protein was developed by cross-linking dopamine with BSA. The results were evaluated by cyclic voltammetry, spectrofluorimetry and first-derivative spectrophotometry in the visible range. Unmodified carbon paste electrodes were used for identify the BSA-5-Cys-DA complexes in solution. This approach allowed overlapping the sluggish kinetics of electron transfer exhibited by proteins with non-metalic redox centers near the surface electrode. Furthermore, a marked increased in fluorescence signal at 350 nm emission together with the appearance of a BSA absorption signal at 370 nm arouse from the protein adducts. In this sense the covalent linkage between a test protein with dopamine show it as a dual candidate able to display both electrochemical and spectroscopic signals, and allow the use of this approach for identify and analyze proteins either in solution or immobilized.