Headpieces

The muscle protein, myosin, exhibits aspects of both fibrous and globular proteins, and its functional domains play quite different roles. The tail domains have a pronounced tendency to aggregate, causing myosin molecules to form thick bipolar filaments. The head domains (Figure 8.3) with their attached light chains are often called headpieces. The headpieces have a strong tendency to bind to actin. The link between the headpiece of myosin and actin is an essential part of the process of muscular contraction.

See also: Actin and Myosin, The Structure of Muscle, The Sliding Filament Model