Calponin reduces shortening velocity in skinned taenia coli smooth muscle fibres

FEBS Letters

Jaworowski, Åsa²  Gimona, Mario¹  Strasser, Peter¹  Anderson, Kurt I.¹  Arner, Anders²  Engström, Martin²  Small, J.Victor¹ 

[1] Institute of Molecular Biology, Austrian Academy of Sciences, Salzburg, Austria;Department of Physiology and Biophysics, Lund University, Sölvegatan 19, S-223 62 Lund, Sweden

关键词: Calponin;    Motility assay;    in vitro;    Shortening velocity;    Smooth muscle;   

DOI  :  10.1016/0014-5793(95)00451-E

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Calponin (4.1–5.9 μM, pig stomach) inhibited maximal shortening velocity (V _max) by 20–25% with only minor influence on force in skinned smooth muscle from guinea-pig taenia coli activated at different Ca²⁺ levels and with thiophosphorylation. Similar results were obtained with a fragment of the N-terminal 1–228 amino acids engineered using a mouse cDNA construct (5.4 μM). Both the native calponin and the fragment inhibited actin filament sliding in a graded manner in an in vitro motility assay. We conclude that calponin influences the kinetics of the actin-myosin interaction in the organised smooth muscle contractile system and that engineered fragments of calponin can be used to probe its action in muscle fibres. The effects can be due to an introduction of an internal load during filament sliding, possibly by decreasing the detachment rates and increasing the cross-bridge time spent in the attached state.

【 授权许可】

Unknown