[Extraction and purification of slow myosin from the masseter muscle of Ovis aries].

Ovis aries masseter is a typical muscle consisting of slow-twitch fibres. The muscle homogeneity is well evidenced histochemically by the myosin ATPase reaction. The extraction and purification of myosin from sheep masseter is reported. After its centrifugation and dialysis followed by ion-exchange chromatography, the protein analysed on SDS polyacrylamide gels showed the usual pattern of slow myosin. The light-chain LC2 was present as a double band, a fact which has already been reported and which could be ascribed to SH group oxidation. From the present data sheep masseter can be considered a good source of slow myosin, and we have used it satisfactorily in the preparation of specific antibodies.