Gentamicin inhibits HSP70-assisted protein folding by interfering with substrate recognition.
We previously reported that gentamicin (GM) specifically binds to heat-shock protein with subunit molecular masses of 70 kDa (HSP70). In the present study, we have investigated the effects of GM binding on HSP70-assisted protein folding in vitro. The C-terminal, and not the N-terminal of HSP70 was found to bind to GM. GM significantly suppressed refolding of firefly luciferase in the presence of HSP70 and HSP40, although the ATPase activity of HSP70 was unaffected by GM. A surface plasmon resonance analysis revealed that GM specifically interferes with the binding of HSP70 to a model peptide that mimics the exposed hydrophobic surface of the folding intermediates. These results indicated that GM inhibits the chaperone activity of HSP70 and may suppress protein folding via inhibition of HSP70 in vivo.
Yamamoto
Soh
S
Department of Life Science, Faculty of Engineering and Resource Science, Akita University, Akita City, Japan.
Nakano
Shunsuke
S
Owari
Kensuke
K
Fuziwara
Kazuhiko
K
Ogawa
Nobuaki
N
Otaka
Michiro
M
Tamaki
Kumiko
K
Watanabe
Sumio
S
Komatsuda
Atsushi
A
Wakui
Hideki
H
Sawada
Ken-Ichi
K
Kubota
Hiroshi
H
Itoh
Hideaki
H
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D001665:Binding Sites; D002846:Chromatography, Affinity; D005839:Gentamicins / Q000737:chemistry / Q000378:metabolism*; D050956:HSP40 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D049409:Luciferases, Firefly / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D017510:Protein Folding; D020349:Surface Plasmon Resonance
D005839:Gentamicins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D049409:Luciferases, Firefly; D000251:Adenosine Triphosphatases