Properties of the amylase produced in carcinoma of the lung

The properties of the amylase produced by carcinoma of the lung were studied. The abnormal amylase recognized in the serum of a patient with carcinoma of the lung had a mobility with beta-position and showed reduced migration to the cathodic side after neuraminidase digestion. This abnormal amylase had a close affinity for Concanavalin A and this affinity was not retarded by the neuraminidase digestion. However, the purified, tumor-extracted, amylase from the same patient had the same electrophoretic migration as normal human salivary amylase and was not affected by neuraminidase treatment. The abnormal affinity for Concanavalin A was not observed in this purified tumor-extracted amylase. It is suggested that some transglycosidation steps are needed for the appearance of the abnormal amylase in the patient's serum, and that the terminal sialic acid is independent of the affinity for Concanavalin A. The dissociation constants of the tumor amylase for several substrates were smaller than those of normal pancreatic or salivary amylases. Moreover, maltotriose had no affinity for the tumor-extracted amylase and it was not digested to maltose and glucose by the purified tumor extracted amylase. These differences in the kinetic properties and in the mode of digestion were of interest in the study of tumor-produced amylases.