tailieunhanh - Báo cáo khoa học: Small heat shock protein Hsp27 prevents heat-induced aggregation of F-actin by forming soluble complexes with denatured actin

Previously, we have shown that the small heat shock protein with apparent molecular mass 27 kDa (Hsp27) does not affect the thermal unfolding of F-actin, but effectively prevents aggregation of thermally denatured F-actin [Pivovarova AV, Mikhailova VV, Chernik IS, Chebotareva NA, Levitsky DI & Gusev NB (2005)Biochem Biophys Res Commun331, 1548–1553], and supposed that Hsp27 prevents heat-induced aggregation of F-actin by forming soluble complexes with denatured actin. | ỊFEBS Journal Small heat shock protein Hsp27 prevents heat-induced aggregation of F-actin by forming soluble complexes with denatured actin Anastasia V. Pivovarova1 2 Natalia A. Chebotareva1 Ivan S. Chernik3 Nikolai B. Gusev3 and Dmitrii I. Levitsky1 4 1 A. N. Bach Institute of Biochemistry Russian Academy of Sciences Moscow Russia 2 Schoolof Bioengineering and Bioinformatics Moscow State University Russia 3 Department of Biochemistry Schoolof Biology Moscow State University Russia 4 A. N. Belozersky Institute of Physico-ChemicalBiology Moscow State University Russia Keywords actin analyticalultracentrifugation dynamic light scattering size exclusion chromatography small heat shock proteins Correspondence D. I. Levitsky A. N. Bach Institute of Biochemistry Russian Academy of Sciences Leninsky prosp. 33 119071 Moscow Russia Fax 7 495 954 2732 Tel 7 495 952 1384 E-mail levitsky@ Received 24 July 2007 revised 10 September 2007 accepted 24 September 2007 doi Previously we have shown that the small heat shock protein with apparent molecular mass 27 kDa Hsp27 does not affect the thermal unfolding of F-actin but effectively prevents aggregation of thermally denatured F-actin Pivovarova AV Mikhailova VV Chernik IS Chebotareva NA Levitsky DI Gusev NB 2005 Biochem Biophys Res Commun 331 1548-1553 and supposed that Hsp27 prevents heat-induced aggregation of F-actin by forming soluble complexes with denatured actin. In the present work we applied dynamic light scattering analytical ultracentrifugation and size exclusion chromatography to examine the properties of complexes formed by denatured actin with a recombinant human Hsp27 mutant Hsp27-3D mimicking the naturally occurring phosphorylation of this protein at Ser15 Ser78 and Ser82. Our results show that formation of these complexes occurs upon heating and accompanies the F-actin thermal denaturation. All the methods show that the size of actin-Hsp27-3D complexes decreases with .