The protein-folding activity of chaperonins correlates with the symmetric GroEL14(GroES7)2 heterooligomer

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 92; no. 26; pp. 12021 - 12025
• Main Authors: Azem, A, Diamant, S, Kessel, M, Weiss, C, Goloubinoff, P
• Format: Journal Article
• Language: English
• Published: United States National Acad Sciences 19.12.1995; National Academy of Sciences
• Subjects: Adenosine Diphosphate - metabolism; Adenosine Triphosphate - metabolism; Animals; Biochemistry; Chaperonin 10 - chemistry; Chaperonin 10 - isolation & purification; Chaperonin 10 - metabolism; Chaperonin 60 - chemistry; Chaperonin 60 - isolation & purification; Chaperonin 60 - metabolism; Chaperonins - metabolism; Cross-Linking Reagents; Kinetics; Macromolecular Substances; Malate Dehydrogenase - chemistry; Malate Dehydrogenase - metabolism; Mitochondria, Heart - enzymology; Molecular biology; Protein Folding; Proteins; Recombinant Proteins - chemistry; Recombinant Proteins - metabolism; Ribulose-Bisphosphate Carboxylase - chemistry; Ribulose-Bisphosphate Carboxylase - metabolism; Swine
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.92.26.12021

Chaperonins GroEL and GroES form, in the presence of ATP, two types of heterooligomers in solution: an asymmetric GroEL14GroES7 "bullet"-shaped particle and a symmetric GroEL14(GroES7)2 "football"-shaped particle. Under limiting concentrations of ATP or GroES, excess ADP, or in the presence of 5'-adenylyl imidodiphosphate, a correlation is seen between protein folding and the amount of symmetric GroEL14(GroES7)2 particles in a chaperonin solution, as detected by electron microscopy or by chemical crosslinking. Kinetic analysis suggests that protein folding is more efficient when carried out by a chaperonin solution populated with a majority of symmetric GroEL14(GroES7)2 particles than by a majority of asymmetric GroEL14GroES7 particles. The symmetric heterooligomer behaves as a highly efficient intermediate of the chaperonin protein folding cycle in vitro.