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Updated: Sep 23, 2026

Analyzing Protein Dynamics Using Hydrogen Exchange Mass Spectrometry
Published on: November 29, 2013
Heat shock protein (hsp90) interacts with smooth muscle calponin and affects calponin-binding to actin
Y Ma1, N V Bogatcheva, N B Gusev
1Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russia.
Abstract:
Interaction of smooth muscle calponin with 90 kDa heat shock protein (hsp90) was analyzed by means of native gel electrophoresis and affinity chromatography. Under conditions used, calponin and hsp90 form a complex with an apparent dissociation constant in the micromolar range. The major hsp90-binding site is located in the N-terminal (residues 7-144) part of calponin. Addition of calponin to actin-tropomyosin complex results in formation of actin bundles. Hsp90 partially prevents bundle formation without affecting the molar ratio calponin/actin in single actin filaments or actin bundles. At low ionic strength, calponin induces polymerization of G-actin. Hsp90 decreases calponin-induced polymerization of G-actin. It is supposed that hsp90 may be involved in the assembly of actin filaments.
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