| 1. |
- Kim, Maria V, et al.
(author)
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Some properties of human small heat shock protein Hsp22 (H11 or HspB8).
- 2004
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In: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 315:4
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Journal article (peer-reviewed)abstract
- Untagged recombinant human small heat shock protein with apparent molecular mass 22 kDa (Hsp22) was obtained in homogeneous state. Size exclusion chromatography and chemical crosslinking with dimethylsuberimidate indicate that Hsp22 forms stable dimers. Being highly susceptible to oxidation Hsp22 forms disulfide crosslinked dimers and poorly soluble high molecular mass oligomers. According to CD spectroscopy oxidation of Hsp22 results in disturbing of both secondary and tertiary structure. Hsp22 possesses a negligibly low autophosphorylation activity and under the conditions used is unable to phosphorylate casein or histone. Hsp22 effectively prevents heat-induced aggregation of yeast alcohol dehydrogenase and bovine liver rhodanese with chaperone activity comparable to that of recombinant human small heat shock protein with apparent molecular mass 20 kDa (Hsp20).
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| 2. |
- Kim, Maria V, et al.
(author)
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Structure and properties of K141E mutant of small heat shock protein HSP22 (HspB8, H11) that is expressed in human neuromuscular disorders.
- 2006
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In: Archives of Biochemistry and Biophysics. - : Elsevier BV. - 0003-9861 .- 1096-0384. ; 454:1
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Journal article (peer-reviewed)abstract
- Some properties of the K141E mutant of human HSP22 that is expressed in distal hereditary motor neuropathy were investigated. This mutation slightly decreased intrinsic fluorescence of HSP22 and induced changes in the far UV CD spectra that correlate with increase of disordered structure. Destabilized K141E mutant was more susceptible to trypsinolysis than the wild type protein. Mutation K141E did not significantly affect the hydrophobic properties measured by bis-ANS binding and did not affect the quaternary structure of HSP22. With insulin as a substrate the chaperone-like activity of K141E mutant and the wild type protein were similar. However with alcohol dehydrogenase and rhodanese the chaperone-like activity of K141E mutant was remarkably lower than the corresponding activity of the wild type protein. It is concluded that K141E mutation induces destabilization of HSP22 structure and probably by this means diminish the chaperone-like activity of HSP22 with certain protein substrates.
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| 3. |
- Panasenko, Olesya O, et al.
(author)
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Interaction of the small heat shock protein with molecular mass 25 kDa (hsp25) with actin.
- 2003
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In: European Journal of Biochemistry. - 0014-2956 .- 1432-1033. ; 270:5
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Journal article (peer-reviewed)abstract
- The interaction of heat shock protein with molecular mass 25 kDa (HSP25) and its point mutants S77D + S81D (2D mutant) and S15D + S77D + S81D (3D mutant) with intact and thermally denatured actin was analyzed by means of fluorescence spectroscopy and ultracentrifugation. Wild type HSP25 did not affect the polymerization of intact actin. The HSP25 3D mutant decreased the initial rate without affecting the maximal extent of intact actin polymerization. G-actin heated at 40-45 degrees C was partially denatured, but retained its ability to polymerize. The wild type HSP25 did not affect polymerization of this partially denatured actin. The 3D mutant of HSP25 increased the initial rate of polymerization of partially denatured actin. Heating at more than 55 degrees C induced complete denaturation of G-actin. Completely denatured G-actin cannot polymerize, but it aggregates at increased ionic strength. HSP25 and especially its 2D and 3D mutants effectively prevent salt-induced aggregation of completely denatured actin. It is concluded that the interaction of HSP25 with actin depends on the state of both actin and HSP25. HSP25 predominantly acts as a chaperone and preferentially interacts with thermally unfolded actin, preventing the formation of insoluble aggregates.
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