pH-induced changes of the structure of small heat shock proteins with molecular mass 24/27kDa (HspB1).
The effect of pH on the structure of recombinant chicken Hsp24, human Hsp27 and their 3D mutants mimicking phosphorylation at Ser15, Ser77/78, and Ser81/82 was analyzed. Circular dichroism and fluorescent spectroscopy indicate that changes of pH in the range 6.0-7.5 weakly affected the secondary and tertiary structure of the wild type proteins, but induced noticeable changes in the structure of their 3D mutants. According to size-exclusion chromatography and analytical ultracentrifugation variation of pH-induced pronounced changes in the quaternary structure of small heat shock proteins and acidification resulted in accumulation of large oligomers of Hsp24/27. It is concluded that small changes of pH strongly affect the quaternary structure of small heat shock proteins and by this means can influence their functioning in the cell.
Chernik
Ivan S
IS
Department of Biochemistry, School of Biology, Moscow State University, Moscow 119992, Russia.
Panasenko
Olesya O
OO
Li
Yi
Y
Marston
Steven B
SB
Gusev
Nikolai B
NB
D000818:Animals; D002850:Chromatography, Gel; D002942:Circular Dichroism; D031541:Fluorescence Resonance Energy Transfer; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D018832:Molecular Chaperones; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000737:chemistry*; D020836:Protein Structure, Quaternary; D013050:Spectrometry, Fluorescence; D014461:Ultracentrifugation
D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins