Monomeric chaperonin-60 and its 50-kDa fragment possess the ability to interact with non-native proteins, to suppress aggregation, and to promote protein folding.

摘要: Chaperonin-60 is usually isolated as a tetradecameric form arranged two stacked seven-member rings, and this structure has been considered to be required for promoting protein folding. However, monomeric chaperonin-60 (cpn60m), from holo-chaperonin of Thermus thermophilus, its proteolytic 50-kDa fragment, which lacks amino-terminal 78 amino acid residues, can interact with non-native rhodanese lactate dehydrogenase, suppress formation aggregates, promote productive folding under the appropriate conditions. different chaperonin-60, promoted by cpn60m fragment produces lower yields active enzymes does not require ATP or chaperonin-10. These effects are due transient reassembly into tetradecamer during reaction, since immobilized both reassemble tetradecamer, still An excess amount shows an inhibitory effect on MgATP-triggered holochaperonin-dependent folding, indicating same species proteins. Thus, intrinsic activity molecular chaperone region cpn60 dispensable activity.