Properties of glycolytic and related enzymes of normal and malignant human uterine tissues studied to optimise assay conditions.

The properties of 12 enzymes related to the glycolytic and oxidative metabolism of glucose were examined in normal and malignant epithelium of human uterine tissues to develop optimised assays suitable for both types of tissue and to delineate important kinetic differences that may exist between them. All assays gave acceptable long-term precision, although instability of phosphofructokinase and 6-phosphogluconate dehydrogenase prevented proper assessment; and all were linear with concentration to an absorbance change of 0.04/min, or more in the case of several enzymes. Notable differences between pyruvate kinase of normal and malignant uterine epithelium were found with D-fructose-1,6-diphosphate (FDP) which caused significantly greater activation of the latter as well as a dramatic reduction in Km for phosphoenol pyruvate; inhibition by DL-alanine was greater for pyruvate kinase of malignant than normal cervix epithelium, whereas endometrium did not show this difference. The ratio of aldolase activity with FDP to that with D-fructose-1-phosphate was greater in malignant than in normal cervix epithelium, no significant difference being apparent in endometrium.