Abstract
Extracts of codling muscle with solvents of pH 6.5 and 7.5 and of ionic strengths from 0.05 to 0.50 were analyzed by electrophoresis and ultracentrifuging and the results compared with previous data. There are indications of a differential extractability of the proteins soluble at low ionic strength (0.2 or less). Actomyosin is extractable from very fresh codling muscle at ionic strengths as low as 0.1 and pH 7.5, but quickly becomes insoluble. It is not extractable from fish under the same conditions after rigor mortis. Monodisperse myosin is present in extracts of codling muscle made at an ionic strength of 0.3 or higher, pH 6.5 and 7.5. Codling myosin is extremely labile and rapidly aggregates either on standing in the cold or during precipitation.