Protein-surfactant interactions: A tale of many states

► This review summarizes advances in protein surfactant interactions since the 1990s. ► Shared micelles are key to protein denaturation below the cmc. ► Numerous micellar denaturation mechanisms occur above the cmc. ► Mixed micelles are highly useful tools to reversibly unfold membrane proteins. ► Chain length and micelle composition both modulate protein denaturation mechanisms.