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. (C) 2000 Elsevier Science B.V.
|Original language||English (US)|
|Number of pages||11|
|Journal||Biochimica et Biophysica Acta - Protein Structure and Molecular Enzymology|
|State||Published - Feb 9 2000|
ASJC Scopus subject areas
- Structural Biology
- Molecular Biology