Artificial chaperoning of insulin, human carbonic anhydrase and hen egg lysozyme using linear dextrin chains - a sweet route to the native state of globular proteins

Linear dextrins (alpha-1,4-D-glucopyranoside chains) are known to possess a mphiphilic surfaces and solubilize lipophilic compounds, We have assessed t he ability of this amphiphilic surface of dextrin to inhibit the self-aggre gation and assist the refolding of proteins, Addition of decameric dextrin, or dextrin-10, in the renaturation buffer improves the refolding yield of human carbonic anhydrase from its guanidinium chloride-induced denatured st ate. It is also seen to inhibit the self-aggregation of insulin. The abilit y of dextrin-10 to interact with cetyltrimethylammonium bromide and postpon e its critical micellar concentration allows the use of destrin-10 as a 'de tergent stripping agent' in a no, el artificial chaperoning process describ ed earlier. The aggregation of human carbonic anhydrase and lysozyme upon r efolding is prevented by cetyltrimethylammonium bromide due to the formatio n of a protein-detergent complex; dextrin-10 strips off the detergent from the complex and allow the proteins to fold, thus increasing the renaturatio n yield, Dextran-4 (the alpha-1,6-D-glucopyranoside chain), which does not exhibit amphiphilic properties, does not help in such artificial chaperonin g. (C) 1999 Federation of European Biochemical Societies.