Tropomyosin‐troponin complex stabilizes the pointed ends of actin filaments against polymerization and depolymerization

FEBS Letters

Weigt, Christiane¹  Schoepper, Beate¹  Wegner, Albrecht¹ 

[1] Institute of Physiological Chemistry, Ruhr-University Bochum, PO Box 102148, D-4630 Bochum, FRG

关键词: Actin;    Tropomyosin;    Troponin;    Polymerization;    Fluorescence;   

DOI  :  10.1016/0014-5793(90)80119-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown