Chaperonin function--effects of crowding and confinement

Chaperonins assist in the acquisition of native protein structure in the cell by providing a shielded environment for a folding polypeptide chain, generated by the interior surface of their cylindrical structure. The folding chain is isolated from the highly crowded cytoplasm, but at the same time confined within the chaperonin folding cage. Both confinement and macromolecular crowding can affect folding kinetics and yields, the modus operandi of chaperonins and their interaction with their protegés. Recent experimental data, as well as computer simulations, provide increasing evidence that the particular physico-chemical conditions prevailing in the cellular interior have to be taken into account when trying to unravel the processes of cellular protein folding.