THE BIOCHEMICAL PROPERTIES OF THE MACROAMYLASES IN THREE PATIENTS

The biochemical properties of the macroamylases found in three patients were exermined. The class of heavy chain of the amylase-linked immunoglobulin was proved to be alpha in all the cases, and the type of light chain was determined to be lambda in two cases, kappa in the other. The amylase-immunoglobulin complexes were completely dissociated at pH 5.0 or by Con-A affinity chromatography. The zymograms of dissociated amylase were normal. When free immunoglobulins released by acidification were mixed with purified salivary or pancreatic amylase, the immunoglobulins recombined with both amylases in two cases, but only with pancreatic amylase in one case. In maltopentaose hydrolysis, the Km values of these macroamylases were slightly smaller than those of normal serum, salivary, and pancreatic amylase.