title: Refolding of target proteins from a "rigid" mutant chaperonin demonstrates a minimal mechanism of chaperonin binding and release.
abstract: One of the most interesting facets of GroEL-facilitated protein folding lies in the fact that the requirement for a successful folding reaction of a given protein target depends upon the refolding conditions used. In this report, we utilize a mutant of GroEL (GroEL T89W) whose domain movements have been drastically restricted, producing a chaperonin that is incapable of utilizing the conventional cyclic mechanism of chaperonin action. This mutant was, however, still capable of improving the refolding yield of lactate dehydrogenase in the absence of both GroES and ATP hydrolysis. A very rapid interconversion of conformations was detected in the mutant immediately after ATP binding, and this interconversion was inferred to form part of the target release mechanism in this mutant. The possibility exists that some target proteins, although dependent on GroEL for improved refolding yields, are capable of refolding successfully by utilizing only portions of the entire mechanism provided by the chaperonins.
authors.affiliation: Department of Biotechnology, Faculty of Engineering, Tottori University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mizobata
authors.forename: M
authors.initials: M
authors.lastname: Kawagoe
authors.forename: K
authors.initials: K
authors.lastname: Hongo
authors.forename: J
authors.initials: J
authors.lastname: Nagai
authors.forename: Y
authors.initials: Y
authors.lastname: Kawata
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D018834:Chaperonin 60 / Q000378:metabolism; D018833:Chaperonins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009711:Nucleotides / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D013050:Spectrometry, Fluorescence; D013210:Staphylococcus / Q000201:enzymology; D013884:Thiosulfate Sulfurtransferase / Q000737:chemistry / Q000378:metabolism; D013912:Threonine / Q000737:chemistry; D014364:Tryptophan / Q000737:chemistry / Q000378:metabolism
chemical_list: D018834:Chaperonin 60; D009711:Nucleotides; D013912:Threonine; D014364:Tryptophan; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase; D013884:Thiosulfate Sulfurtransferase; D018833:Chaperonins; D010751:Phosphopyruvate Hydratase