A non-competitive inhibition by glucose-6-P1 of brain (1, 2) and other animal tissue (1) hexokinases has been described, as well as a similar inhibition of brain hexokinase by L-sorbose-1-P (3). The present paper is concerned with the specificity for inhibition of brain hexokinase by glucose6-P and related compounds. Ry means of a comparison of the structures of twenty-five compounds, six of xv...

the study on biochemical changes in brain tissue indicates that there are considerable variations in metabolism of energy in this tissue within the first three weeks of life. this phenomenon coincides with the increase of brain energy during that period of life. there are, indeed, various factors, involved in the changing process. hormones and thyroid hormones in particular are of the most impo...

Rat skeletal-muscle hexokinase was partially purified by ammonium sulphate fractionation and gel filtration. The mechanism of the skeletal-muscle hexokinase was studied kinetically by initial-velocity analysis and product inhibition. Glucose 6-phosphate was a non-competitive inhibitor of glucose and ATP. ADP was a non-competitive inhibitor of glucose and a competitive inhibitor of ATP. The data...

In tumoral cells derived from the insulin-producing rat cell line RINm5F, both low- and high-Km glucose-phosphorylating enzymic activities were present. The hexokinase-like enzyme was inhibited by glucose 6-phosphate and displayed a greater affinity for but lower maximal velocity with alpha-D-glucose than beta-D-glucose. A comparable anomeric behavior of hexokinase was observed in breast cancer...

& Rose (1970) have suggested the possibility of negative co-operativity in yeast hexokinase (PI,), an enzyme that appears to be identical with yeast hexokinase B. In view of the increasing prevalence of transient kinetics and the possible significance of such behaviour in co-operativity, we now report experiments documenting a slow change in hexokinase activity during assay and suggest a unique...

I. The activities of hexokinase (EC 2.7.1.1) and phosphofructokinase (EC 2.7.1.11) have been studied in homogenates of adipose tissue taken from human diabetics, fasting and control patients. 2. Three isoenzymes of hexokinase were observed with apparent K; values for glucose of 1·04 x lO-sM, 2·6 X 1O-4M and 2·9 x 10-4M, respectively. 3. No change in activity of hexokinase was found in adipose t...

Previous work has indicated that two types (A and B) of binding sites for hexokinase exist, but in different proportions, on brain mitochondria from various species. Hexokinase is readily solubilized from Type A sites by glucose 6-phosphate (Glc-6-P), while hexokinase bound to Type B sites remains bound even in the presence of Glc-6-P. Type A:Type B ratios are approximately 90:10, 60:40, 40:60,...

Rat liver 'glucokinase' (hexokinase D) catalyses the phosphorylation of fructose with a maximal velocity about 2.5-fold higher than that for the phosphorylation of glucose. The saturation function is hyperbolic and the half-saturation concentration is about 300 mM. Fructose is a competitive inhibitor of the phosphorylation of glucose with a Ki of 107 mM. Fructose protects hexokinase D against i...

PURPOSE Although currently classified as variants of follicular neoplasms (FNs), Hürthle cell neoplasms (HCNs) exhibit distinct biological characteristics. Hence, the metabolism of both neoplasms may also be different. The aims of this study were to investigate and compare the expression of glycolysis-related proteins in HCNs and FNs and to determine the clinical implications of such expression...