Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of oxidative stress, a state often resulting from exposure to high levels of reactive oxygen species, e.g. superoxide anions, hydrogen peroxide (H2O2), and hydroxyl radicals.

The process of assisting in the disassembly of non-covalent linkages in a protein or protein aggregate, often where the proteins are in a non-functional or denatured state.

The hydrolysis of proteins into smaller polypeptides and/or amino acids by cleavage of their peptide bonds.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.