title: Small heat shock protein Hsp27 protects myosin S1 from heat-induced aggregation, but not from thermal denaturation and ATPase inactivation.
abstract: We applied different methods, such as turbidity measurements, dynamic light scattering, differential scanning calorimetry and co-sedimentation assay, to analyze the interaction of small heat shock protein Hsp27 with isolated myosin head (myosin subfragment 1, S1) under heat-stress conditions. Upon heating at 43 degrees C, Hsp27 effectively suppresses S1 aggregation, and this effect is enhanced by mutations mimicking Hsp27 phosphorylation. However, Hsp27 was unable to prevent thermal unfolding of myosin heads and to maintain their ATPase activity under heat-shock conditions.
authors.affiliation: A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky prosp. 33, Moscow 119071, Russia.
authors.forename: Denis I
authors.initials: DI
authors.lastname: Markov
authors.forename: Anastasia V
authors.initials: AV
authors.lastname: Pivovarova
authors.forename: Ivan S
authors.initials: IS
authors.lastname: Chernik
authors.forename: Nikolai B
authors.initials: NB
authors.lastname: Gusev
authors.forename: Dmitrii I
authors.initials: DI
authors.lastname: Levitsky
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000737:chemistry*; D000818:Animals; D002152:Calorimetry, Differential Scanning; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics; D006358:Hot Temperature; D006801:Humans; D008027:Light; D018832:Molecular Chaperones; D009154:Mutation; D015879:Myosin Subfragments / Q000037:antagonists & inhibitors / Q000737:chemistry*; D009363:Neoplasm Proteins / Q000737:chemistry* / Q000235:genetics; D010766:Phosphorylation; D011489:Protein Denaturation; D017510:Protein Folding; D051381:Rats; D012542:Scattering, Radiation
chemical_list: D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D015879:Myosin Subfragments; D009363:Neoplasm Proteins; D000251:Adenosine Triphosphatases