Effect of H2O2 on the formation of irreversible SDS-resistant Cu(II)-induced IgG aggregates

LOPEZ MONTAÑANA, L; PAGANO, GUADALUPE; FACIO ML; REPETTO MG; SAPORITO MAGRIÑA C

Congreso; VI International Congress in Translational Medicine. Maestría Internacional en Ciencias Biomédicas (IMBS). Universidad de Freiburg (Alemania) y Universidad de Buenos Aires.; 2023

Cupric ions (Cu(II)) promote the formation of protein aggregates which in plasma can be found as detergent resistant aggregates (DRA). Due to its reactivity with hydrogen peroxide (H2O2), free Cu(II) have to be negligible within cells. In plasma, Cu(II) is found in the micromolar range. However, in pathologies such as Wilson disease, it may drastically rise up to concentrations as high as 45 µM. In previous work we have shown that IgGs are selectively aggregated by Cu(II). Therefore, oscillations in plasma free Cu(II) may drive IgG reversible aggregation. Objective: To determine whether Cu(II)-induced IgG aggregates become irreversibly aggregated by H2O2. Methods: Optic density (OD), Lowry assay, SDS-PAGE, bidimensional electrophoresis, silver staining, western blotting. Results: Cu(II) and Zn(II) induce IgG aggregation at 5 µM and 20 µM, respectively (p