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Interaction of smooth muscle calponin and desmin
Author(s) -
Wang Peiyi,
Gusev Nikolai B.
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00824-1
Subject(s) - desmin , calponin , intermediate filament , chemistry , tropomyosin , actin , cytoskeleton , biophysics , neurofilament , microbiology and biotechnology , biochemistry , biology , vimentin , immunohistochemistry , cell , immunology
Interaction of smooth‐muscle calponin and desmin was analyzed by means of ultracentrifugation, fluorescent spectroscopy and affinity chromatography. At low and intermediate ionic strength (30–50 mM NaCl) calponin is cosedimented with desmin with an apparent dissociation constant 3–15 μM and stoichiometry of 1 calponin/4–6 desmin. Calmodulin decreases the quantity of calponin bound to desmin. Increase of ionic strength up to 150 mM weakens calponin‐desmin interaction, but even at this ionic strength part of calponin remains bound to desmin. Calponin increases the rate and extent of fluorescence quenching induced by polymerization of 5‐iodoacetamidofluorescein‐labeled desmin. Affinity chromatography data indicate that desmin‐binding sites are located in the N‐terminal 22 kDa fragment of calponin. Since calponin interacts with desmin with an affinity comparable with that of, e.g., tropomyosin and myosin we suppose that calponin‐desmin interaction may be important for cytoskeleton organization.