Actin may contribute to the power stroke in the binary actomyosin system.
At the physiological protein osmotic pressure, the angle formed between the long axis of the actin monomer and the pointed end of the filament axis is roughly 61 degrees in F-actin and about 90 degrees in the myosin subfragment 1--decorated F-actin. This implies that, in the course of the contractile cycle, actin itself contributes, by about 4 nm, to the displacement of the actin filament toward the center of the sarcomer.
Grazi
E
E
Instituto di Chimica Biologica, Università di Ferrara, Italy.
Magri
E
E
Schwienbacher
C
C
Trombetta
G
G
D000199:Actins / Q000502:physiology*; D000205:Actomyosin / Q000502:physiology*; D000818:Animals; D008954:Models, Biological; D009119:Muscle Contraction; D009132:Muscles / Q000502:physiology*; D015879:Myosin Subfragments / Q000502:physiology*; D009997:Osmotic Pressure; D011817:Rabbits; D013314:Stress, Mechanical
D000199:Actins; D015879:Myosin Subfragments; D000205:Actomyosin