Actomyosin solution isolated from carp muscle was frozen and stored with 20 amino acids. The cryoprotective effect of the additives was studied by following the changes in the solubility and the electron microscopic pictures of the protein.
The results with the solubility change were classified into six groups with respect to the rate of the change; those with the electron microscopic pictures were classified into three groups depend-ing on the extent of the deformation of the filaments. Glu, Asp, and some others showed good cryoprotective effects in both the solubility and the electron microscopic pictures. Phe, Leu, and some others were less effective. Changes in solubility and in electron microscopic pictures were generally found to proceed in parallel to each other, but some exceptional cases were found for Pro, Gly, etc.