Extensive carboxypeptidase digestion of clam alpha-paramyosin. The effect on the size and solubility of the residual protein.

The purpose of this paper is to provide further evidence that the C-terminal 1/3 of the alpha-paramyosin molecule is the portion responsible for the low solubility of alpha-paramyosin at neutral pH and low ionic strength. This was accomplished by digesting from the C-terminal end with carboxypeptidases A and B in 2 M urea at pH 8.5. The solubility increased as the molecular weight decreased until a stable segment 2/3 of the size of the molecule remained.