Tropomyosin pp 95-109 | Cite as

Tropomyosin and the Steric Mechanism of Muscle Regulation

Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 644)


Contraction in all muscles must be precisely regulated and requisite control systems must be able to adjust to changes in physiological and myopathic stimuli. In this chapter, we outline the structural evidence for a steric mechanism that governs muscle activity. The mechanism involves calcium and myosin induced changes in the position of tropomyosin along actin-based thin filaments. This process either blocks or uncovers myosin crossbridge binding sites on actin and consequently regulates crossbridge cycling on thin filaments, the sliding of thin and thick filaments and muscle shortening and force production.


Muscle Regulation Myosin Binding Troponin Complex Vertebrate Striate Muscle Crossbridge Cycle 
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© Landes Bioscience and Springer Science+Business Media 2008

Authors and Affiliations

  1. 1.Department of Physiology and BiophysicsBoston University School of MedicineBostonUSA
  2. 2.Department of Cell BiologyUniversity of Massachusetts Medical SchoolWorcesterUSA

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