Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A blotting method is described to detect enzymes that do not normally yield a colored product. The method can be used for dot blotting as well as blotting after gel electrophoresis of many enzymes if the reactions they catalyze can be coupled to an oxidase or a dehydrogenase. The latter, designated "auxiliary enzymes," are preimmobilized on membranes of nitrocellulose or positively charged nylon and the reaction they catalyze is coupled with reduction of tetrazolium salt to yield colored formazan on areas of the transfer membrane occupied by the blotted enzymes. In the examples reported here, preimmobilized glucose oxidase, L-amino acid oxidase, xanthine oxidase, malate dehydrogenase, and a mixture of hexokinase and glucose-6-phosphate dehydrogenase were used as auxiliary enzymes to detect blotted invertase, leucine aminopeptidase, purine nucleoside phosphorylase, fumarase, and adenylate kinase, respectively. Detection limits varied, but never exceeded 100 ng for these enzymes. After blotting from polyacrylamide gels, the fumarase assay was the most sensitive of those investigated, detecting 10 ng of enzyme used for electrophoresis. Invertase, a glycoprotein, was detected with higher sensitivity on nitrocellulose membranes when concanavalin A was present on the membrane in addition to the auxiliary enzyme, glucose oxidase. On blots from isoelectric focusing gels, the assay detected two isozymes of purine nucleoside phosphorylase in a sample from calf spleen and at least five isozymes of this enzyme in lysates from human red cells.
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PMID:Activity staining of blotted enzymes by reaction coupling with transfer membrane-immobilized auxiliary enzymes. 245 38

The activities of the key glycolytic enzymes phosphofructokinase (PFK), pyruvate kinase (PK) and hexokinase in addition to adenosine deaminase, purine nucleoside phosphorylase (PNP) and lactate dehydrogenase (LDH) have been measured in lymphocytes from 39 cases with B-chronic lymphocytic leukaemia (B-CLL). According to the percentage of circulating large non-granular atypical lymphocytes (AL) the B-CLL cases were classified as: typical (less than 10% of AL; 28 cases) and atypical (10-25% AL; 11 cases). In both groups the median lymphocyte volume (MLV) was assessed and correlated with the correspondent enzyme activities. The MLV of B-CLL lymphocytes was significantly (p less than 0.001) decreased (149.9 +/- 19.4 fl) as compared to normal B lymphocytes (175.1 +/- 14.5 fl) and it was significantly (p less than 0.001) lower in typical B-CLL (141.8 +/- 12.2 fl) than in atypical B-CLL (172.0 +/- 17.2 fl). Furthermore, in patients with typical B-CLL, all enzyme activities when expressed as U/10(9) cells were, with the exception of PFK, significantly decreased compared to normal B lymphocytes. However, when the results were expressed as U/ml cells, only PK, PNP and LDH remained significantly low. These findings demonstrate that the determination of MLV in addition to morphology may be a useful tool to distinguish the two previously described morphological B-CLL variants (typical and atypical) and that these two different B-CLL groups are also distinguishable on the basis of three enzyme activities, PK, PNP and LDH which have been shown to be less dependent on cell size than the other enzymes, also studied here.
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PMID:Relationship between lymphocyte size and enzyme activities in two morphological variants of B-chronic lymphocytic leukaemia. 252 63

Kinetic isotope effects are increasingly applied to investigate enzyme reactions and have been used to understand transition state structure, reaction mechanisms, quantum mechanical hydride ion tunneling and to design transition state analogue inhibitors. Binding isotope effects are an inherent part of most isotope effect measurements but are usually assumed to be negligible. More detailed studies have established surprisingly large binding isotope effects with lactate dehydrogenase, hexokinase, thymidine phosphorylase, and purine nucleoside phosphorylase. Binding reactants into catalytic sites immobilizes conformationally flexible groups, polarizes bonds, and distorts bond angle geometry, all of which generate binding isotope effects. Binding isotope effects are easily measured and provide high-resolution and detailed information on the atomic changes resulting from ligand-macromolecular interactions. Although binding isotope effects complicate kinetic isotope effect analysis, they also provide a powerful tool for finding atomic distortion in molecular interactions.
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PMID:Binding isotope effects: boon and bane. 1786 63

We examined the possible implication of ras in the regulation of the activity of several metabolic enzymes by employing an inducible H-ras expression system (RFLSVrasLAP cell line), in which the addition of IPTG decreases the levels of ras p21 3-fold. We measured the activity of hexokinase (E.C. 2.7.1.1.), glucose phosphate isomerase (E.C. 5.3.1.9), phospho-fructokinase (E.C. 2.7.1.11), aldolase (E.C. 4.1.2.13), phosphoglycerate kinase (E.C. 2.7.2.3), enolase (E.C. 4.2.1.11), pyruvate kinase (E.C. 2.7.1.40), lactate dehydrogenase (E.C. 1.1.1.27), adenosine deaminase (E.C. 3.5.4.4) and purine nucleoside phosphorylase (E.C. 2.4.2.1) from cells grown in the presence and absence of IPTG. We found that the addition of IPTG to RFLSVrasLAP cells led to lower activity of phosphoglycerate kinase (p=0.004), enolase (p=0.027) and pyruvate kinase (p=0.031). Enolase mRNA levels were found to be increased in cells overexpressing either the normal or mutant H-ras. The total rate of glycolysis was not affected by H-ras expression indicating that the implication of H-ras in the activity of phosphoglycerate kinase, enolase and pyruvate kinase may be associated with glycolysis-independent functions of these enzymes. Adenosine deaminase activity was found to increase after IPTG addition (P=0.009), indicating also a possible role for H-ras in the control of the purine nucleotide salvage pathway.
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PMID:T24 h-ras gene-expression increases the activity of phosphoglycerate kinase, enolase and pyruvate-kinase and decreases the activity of adenosine-deaminase in fibroblast cells. 2160 14