Enzyme patterns of glycolysis and gluconeogenesis in rabbit gingiva and the effects of pH on the patterns

Abstract

In order to clarity the enzyme patterns of the glycolytic and gluconeogenetic reactions on the, glycolytic pathway in rabbit gingiva, the conditions for the measurements of the enzyme activities were examined and established on the forward and re verse reactions in 15 enzymes associated with the glycolytic pathway. The difference of each enzyme activity tested in triethanolamine, Hepes and Tris buffers were found to bring about a respectable change of the enzyme pattern due to the kind of buffer used in the assay mixture.
The enzyme patterns at pH 7.4 obtained in the present paper were as follows: 1) hexokinase and 6-phosphofructokinase were suspected to operate as the reg ulatory enzymes of the glycolytic reaction 2) The activities of triosephosphate isomerase and lactate dehydrogenase showed an approximately 10 fold difference between the forward and reverse reactions 3) The rabbit gingiva seemed to have no gluconeogenesis because the e nzyme activities of phosphoenolpyruvate carboxykinase, pyruvate carboxylase and glucose 6-phosphatase associated with gluconeogenesis were undetected.
The effects of various pH levels on the enzyme patterns generall y suggested the accumulation of fructose 1, 6-bisphosphate and overall activities of glycolysis at alkaline pH values, and the accumulation of glucose 6-phosphate and the decrease in glycolytic flux at acidic pH values.