myosin

Term: myosin

Literally meaning: “pertaining to muscle”

Origin: Anc Greek

μυο-/myo-(=combining form meaning muscle) > μυς/mys/ (=muscle) > μύω/myo(=enclosed like the muscle inside body or rat in its nest=epimys)

Coined/History 

The term was coined in 1864 by W. Kuhne who called “myosin” a viscous protein that he had extracted from muscle with concentrated salt solution. Many years later (1939) V. A. Engelhardt and M.N. Lyubimova reported that myosin had ATPase activity. In years 1942 and 1943 A. Szent-Gyogyi and F.B. Straub proved that another protein which was named (by Straub)  “actin” when compined with myosin was responsible for muscle viscosity and contractility.

 Sources

Kühne, W. 1864. Untersuchungen über das Protoplasma und die Contractilitat. W. Engelmann, Leipzig.

Engelhardt, V.A., and M.N. Lyubimova. 1939. Myosin and adenosinetriphosphatase.Nature. 144:668–669.

Straub, F.B. 1942. Actin. Stud. Inst. Med. Chem. Univ. Szeged. II:3–15.

Szent-Györgyi, A. 1943a. The crystallization of myosin and some of its properties and reactions. Stud. Inst. Med. Chem. Univ. Szeged. III:76–85.

Definition

Myosin is any of motor protein from a large family which are involved in motility processes such as muscle  contraction through ATP hydrolysis. Myosins are interact with other motor proteins like actin-filaments. Sarcomeric myosin is a large hexameric protein with two globular heads (conatining binding sites for actin thin filaments and ATP)  and a long coiled-coil a-helical rod.