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Tropomyosin‐troponin complex stabilizes the pointed ends of actin filaments against polymerization and depolymerization
Author(s) -
Weigt Christiane,
Schoepper Beate,
Wegner Albrecht
Publication year - 1990
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(90)80119-4
Subject(s) - depolymerization , tropomyosin , actin , polymerization , chemistry , polymer chemistry , biophysics , polymer science , polymer , biochemistry , organic chemistry , biology
In striated muscle the pointed ends of polar actin filaments are directed toward the center of the sarcomer. Formed filaments keep a constant length of about 1 μm. As polymerization and depolymerization at free pointed ends are not sufficiently slow to account for the constant length of the filaments, we searched for proteins which occur in sarcomers and can stabilize the pointed ends of actin filaments. We observed that tropornyosintroponin complex reduces the rate of association and dissociation of actin molecules at the pointed ends more than 30‐fold. On the average, every 600 s one association or dissociation reaction has been found to occur at the pointed ends near the critical actin monomer concentration.