Ca‐dependent binding of actin to gelsolin

FEBS Letters

Khaitlina, Sofia¹  Hinssen, Horst² 

[1]Institute of Cytology RAS, St. Petersburg, Russia

[2]Biochemical Cell Biology Group, Faculty of Biology, University of Bielefeld, D33501 Bielefeld, Germany

关键词: Gelsolin;    Actin;    Ca-dependence;    Conformational change;    Complex formation;    Limited proteolysis;   

DOI  :  10.1016/S0014-5793(02)02657-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Ca²⁺ of 0.3–1.0 μM induces both the exposure of tryptic cleavage sites within the gelsolin molecule inaccessible in the Ca-free conformation, and binding of one actin monomer to the N-terminal half of gelsolin. On the other hand, gelsolin-induced enhancement of pyrene actin fluorescence was observed only above 50 μM Ca²⁺, and a ternary actin/gelsolin complex preformed in 200 μM Ca²⁺ was stable only above 30 μM Ca²⁺. These results provide direct evidence for Ca-induced transitions from closed to open conformation of the gelsolin molecule in the range of 3×10^-7 to 10⁻⁶ M Ca²⁺. They also suggest that Ca²⁺>10⁻⁵ M is required to stabilize actin–actin contacts in the 2:1 actin/gelsolin complex.

【 授权许可】

Unknown