An Immunochemical Study of the Distribution of Myosin in Glycerol Extracted Muscle

Recent investigations of the distribution of myosin and actin in the skeletal muscle fiber have relied largely on extraction techniques for the differential removal of specific proteins. This work has been reviewed by Hanson and Huxley (1). Because such extraction techniques may remove much soluble material in addition to myosin or actin, conclusions based on density changes within fibers after extractions have seemed somewhat questionable (2). We have, therefore, attempted a more positive localization of myosin in glycerol fibers by the use of the fluorescent antibody method (3, 4). Methods Myosin was prepared from chicken breast muscle by the procedure of Mommaerts and Parrish (5). The first precipitate of myosin was dissolved and reprecipitated 3 times at an ionic strength of 0.05. Traces of material insoluble at ionic strengths of 0.27 to 0.30 were removed in intermediate steps. Antisera were prepared in rabbits by injecting myosin in saline solutions or with alum or aquaphor adjuvants. Sera of good precipitating power were obtained when a total dose of 33 nag. of myosin was given in two brief courses a month apart. The