“…Enzymes that function extracellularly and intracellularly, and from unicellular and multicellular organisms drawn from all three phylogenetic domains have been successfully renatured and assayed. Since many oligomeric proteins express catalytic function only when complexed to their companion polypeptides (15,16), as a class these enzymes are less amenable to successful renaturation following SDS-PAGE than monomeric ones (17). Nevertheless, in many instances ''catalytic'' subunits from both homoand hetero-oligomeric enzymes have been successfully renatured and assayed (18 -22).…”