Actin is a protein macromolecule that is one of the basic components of the actin myofilament – a complex structure that forms the contractile apparatus of the muscle fiber (in addition to actin, troponin and tropomyosin - they are also part of the actin myofilament).
Structure[edit | edit source]
The skeleton of the actin myofilament is formed by F-aktin in the form of a 1 μm long double helix. This double helix is made up of more than 400 G-aktin. Each of the G-actin molecules contains a place that is capable of interacting with the „head“ of myosin. This place is blocked by the tropomyosin molecule during the state of relaxation of the contractile complex.
For more detailed information, see Excitation-contraction coupling in skeletal muscle.
Links[edit | edit source]
Related articles[edit | edit source]
- Myofibril ultrastructure, contraction mechanism
- Connection of excitation and contraction
References[edit | edit source]
- KITTNAR, Otomar. Lékařská fyziologie. 1. edition. Praha : Grada, 2011. 790 pp. ISBN 978-80-247-3068-4.