Macroamylasemia: Variation in the Response of the Macroamylase Complex to Acidification 1

Summary

Acidification had a variable effect on the integrity of the large amylase component in the sera of 21 patients with macro-amylasemia. Reduction of pH to 3.4 resulted in complete dissociation of the macroamylase in 13 cases; partial dissociation occurred in six while two remained unchanged. The response to acidification could be correlated with the sedimentation coefficients of the complexes: macroamylases with the highest coefficients tended not to be affected by acidification; those with the lowest values tended to be completely dissociated, while those with intermediate values tended to be partially dissociated. The variable response to lowering of the pH provides further evidence pointing to heterogeneity of the macroamylase complexes.