IgG becomes irreversibly aggregated in the presence of hydrogen peroxide and Cu(II) ions: implications in vivo

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

Congreso; Conference of Free Radicals in Biology and Medicine.Metallome and Redox Regulation: Its Systemic Health Effects,Redox Mechanisms and Systems Biology: Building an Atlas of the Redox Highways Title:; 2023

Cupric ions (Cu(II)) promote protein aggregation which in plasma can be found as detergent resistant aggregates (DRA). Due to its reactivity with hydrogen peroxide (H2O2), free Cu(II) are negligible within cells. In plasma, Cu(II) is found in the micromolar range and may rise in pathologies such as Wilson Disease. 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, silver staining, western blotting. Results: Cu(II) and Zn(II) induce IgG aggregation at 5 µM and 20 µM, respectively (p