title: Effects of divalent cations on encapsulation and release in the GroEL-assisted folding.
abstract: Chaperonin GroEL assists protein folding in the presence of ATP and magnesium. Recent studies have shown that several divalent cations other than magnesium induce conformational changes of GroEL, thereby influencing chaperonin-assisted protein folding, but little is known about the detailed mechanism for such actions. Thus, the effects of divalent cations on protein encapsulation by GroEL/ES complexes were investigated. Of the divalent cations, not only magnesium, but also manganese ions enabled the functional refolding and release of 5,10-methylenetetrahydroforate reductase (METF) by GroEL. Neither ATP hydrolysis nor METF refolding was observed in the presence of zinc ion, whereas only ATP hydrolysis was induced by cobalt and nickel ions. SDS-PAGE and gel filtration analyses revealed that cobalt, nickel and zinc ions permit the formation of stable substrate-GroEL-GroES cis-ternary complexes, but prevent the release of METF from GroEL.
authors.affiliation: Department of Applied Biological Chemistry, School of Agriculture, Kinki University, 3327-204, Nakamachi, Nara, 631-8505, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Okuda
authors.forename: Chihaya
authors.initials: C
authors.lastname: Sakuhana
authors.forename: Risa
authors.initials: R
authors.lastname: Yamamoto
authors.forename: Rika
authors.initials: R
authors.lastname: Kawai
authors.forename: Yuko
authors.initials: Y
authors.lastname: Mizukami
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Matsuda
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry*; D002412:Cations; D018835:Chaperonin 10 / Q000737:chemistry; D018834:Chaperonin 60 / Q000737:chemistry* / Q000378:metabolism; D018833:Chaperonins / Q000737:chemistry; D003001:Cloning, Molecular; D003035:Cobalt / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D006868:Hydrolysis; D008345:Manganese / Q000737:chemistry; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000737:chemistry; D009532:Nickel / Q000737:chemistry; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry; D015032:Zinc / Q000737:chemistry
chemical_list: D002412:Cations; D018835:Chaperonin 10; D018834:Chaperonin 60; D011994:Recombinant Proteins; D003035:Cobalt; D008345:Manganese; D009532:Nickel; D000255:Adenosine Triphosphate; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D018833:Chaperonins; D015032:Zinc