Work

Chaperonin Function: Folding by Forced Unfolding

Year: 1999

Type: article

Abstract: The ability of the GroEL chaperonin to unfold a protein trapped in a misfolded condition was detected and studied by hydrogen exchange. The GroEL-induced unfolding of its substrate protein is only partial, requires the complete chaperonin system, and is accomplished within the 13 seconds required for a single system turnover. The binding of nucleoside triphosphate provides the energy for a single unfolding event; multiple turnovers require adenosine triphosphate hydrolysis. The substrate protein is released on each turnover even if it has not yet refolded to the native state. These results suggest that GroEL helps partly folded but blocked proteins to fold by causing them first to partially unfold. The structure of GroEL seems well suited to generate the nonspecific mechanical stretching force required for forceful protein unfolding.

Source: Science

DOI: 10.1126/science.284.5415.822

Authors: Mark Shtilerman, George H. Lorimer, S. Walter Englander

Institutions: University of Pennsylvania, University of Maryland, College Park

Language: English

Topic: Heat shock proteins research

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funder: National Institute of General Medical Sciences

Awards: G355870977, Protein structure and function by hydrogen exchange mass spectrometry analysis