title: Zinc-L-carnosine binds to molecular chaperone HSP70 and inhibits the chaperone activity of the protein.
abstract: In this study, we have investigated the specific binding proteins of Zinc-L-carnosine (Polaprezinc) using Polaprezinc-affinity column chromatography in vitro. A protein having a 70-kDa molecular mass was eluted by the linear gradient of 0-1.0 mM Polaprezinc from the affinity column and the protein was identified as the molecular chaperone HSP70 by immunoblotting. The chaperone activity of HSP70 was completely suppressed by Polaprezinc. The ATPase activity of HSP70 was affected to some extent by the reagent. In the circular dichroism (CD) spectrum, the secondary structure of HSP70 was changed in the presence of Polaprezinc, i.e. it decreased in the α-helix. We have determined the Polaprezinc-binding domain of HSP70 by using recombinant HSP70N- and C-domains. Although Polaprezinc could bind to both the N-terminal and the C-terminal of HSP70, the HSP70N-domain has a high affinity to the drug. Regarding the peptide cleavage of the HSP70N- and C-domains with proteinase K, the intact HSP70N still remained in the presence of Polaprezinc. On the other hand, the quantity of the intact C-domain slightly decreased under the same conditions along with the newly digested small peptides appeared. It has been suggested that Polaprezinc binds to HSP70 especially in the N-domains, suppresses the chaperone activity and delays an ATPase activities of HSP70.
authors.affiliation: Department of Life Science, Graduate School and Faculty of Engineering and Resource Science, Akita University, Akita 010-8502, Japan.
authors.forename: Asami
authors.initials: A
authors.lastname: Haga
authors.forename: Tomoya
authors.initials: T
authors.lastname: Okamoto
authors.forename: Shintaroh
authors.initials: S
authors.lastname: Yamada
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kubota
authors.forename: Ann
authors.initials: A
authors.lastname: Sanpei
authors.forename: Shota
authors.initials: S
authors.lastname: Takahashi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakayama
authors.forename: Miki
authors.initials: M
authors.lastname: Nagai
authors.forename: Michiro
authors.initials: M
authors.lastname: Otaka
authors.forename: Toshio
authors.initials: T
authors.lastname: Miyazaki
authors.forename: Wataru
authors.initials: W
authors.lastname: Nunomura
authors.forename: Ewa
authors.initials: E
authors.lastname: Grave
authors.forename: Hideaki
authors.initials: H
authors.lastname: Itoh
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000302:isolation & purification; D000818:Animals; D001665:Binding Sites; D001923:Brain Chemistry; D002336:Carnosine / Q000031:analogs & derivatives* / Q000737:chemistry; D002846:Chromatography, Affinity; D002942:Circular Dichroism; D019286:Endopeptidase K / Q000737:chemistry; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry* / Q000302:isolation & purification; D007700:Kinetics; D009942:Organometallic Compounds / Q000737:chemistry*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013552:Swine; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D018840:HSP70 Heat-Shock Proteins; D009942:Organometallic Compounds; D017967:Zinc Compounds; C061957:polaprezinc; D002336:Carnosine; D019286:Endopeptidase K; D000251:Adenosine Triphosphatases
keywords: ATPase; HSP70; chaperone activity; molecular chaperone; zinc-l-carnosine