Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.4.17 (adenosine deaminase)
 5,206 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Changes in hepatic purine enzyme activities of chicks fed diets containing 11%, 20%, 43% and 80% protein were correlated with protein intake and uric acid production in order to identify those enzymes with activities that parallel closely and may regulate uric acid production. Nucleoside phosphorylase, xanthine dehydrogenase, adenylosuccinate synthetase and adenosine kinase correlated positively with protein intake and uric acid production. Adenosine deaminase, 5'-nucleotidase (AMP), adenylate deaminase and adenine phosphoribosyltransferase correlated negatively with protein intake and uric acid production. Hypoxanthine phosphoribosyltransferase and 5'-nucleotidase (IMP) were unaffected by protein intake and did not correlate with uric acid production. The ratio of adenosine kinase to adenosine deaminase correlated positively with protein intake and uric acid production. The increased activities of adenylosuccinate synthetase and adenosine kinase, along with the reduced activities of 5'-nucleotidase and adenylate deaminase, in liver from chickens fed the 80% compared with the 11% protein diet demonstrate enhanced synthesis of adenine nucleotides. Since adenine nucleotides are essential cofactors for de novo purine synthesis, it is proposed that adenylosuccinate synthetase, adenosine kinase, 5'-nucleotidase and adenylate deaminase are key enzymes involved in the regulation of purine biosynthesis.
 ...
PMID:Protein intake, hepatic purine enzyme levels and uric acid production in growing chicks. 61 42

Adenosine deaminase is an important enzyme in purine metabolism, and patients with abnormal lymphocyte and erythrocyte adenosine deaminase levels have been shown to have impaired immune competence. Since immune factors have been shown to be important in patients with transitional cell carcinoma of the bladder we studied adenosine deaminase activity in the hemic cells of 48 patients with this tumor. Lymphocyte adenosine deaminase levels were elevated in patients with transitional cell carcinoma and correlated with stage, activity, clinical course and tumor resection but not with tumor grade. Erythrocyte adenosine deaminase levels also were elevated in patients with transitional cell carcinoma but did not correlate with other disease parameters. Lymphocyte adenosine deaminase activity in patients with transitional cell carcinoma may be a sensitive indicator of disease activity and further studies may provide insight into the host-tumor relationship at the enzyme level.
 ...
PMID:Adenosine deaminase activity in patients with carcinoma of the bladder. 64 89

Immobilised inosine (6a) and adenosine (6c) and their 5'-phosphates have been synthesized. Reaction of the nucleosides with ethyl levulinate, followed by saponification or phosphorylation and then saponification, gave the 2',3'-O-[1-(2-carboxyethyl)ethylidene] derivatives 3 and 4 and the corresponding 5'-phosphates 2b and 2d. 6-Aminohexylagarose (5) was severally coupled to 2b, 2d, 3, and 4 through the carboxyl groups to give the polymers 6a-d. Adenosine deaminase converts 3 into 4, and 6c into 6a. The polymers can be used as affinity resins for adenosine deaminase, which is bound more strongly to 6c than to 6a. The operational capacity of 6a for adenosine deaminase is constant at 15--25 degrees, but decreases by approximately 16% from 25 degrees to 35 degrees. The resin 6a has been used to separate adenosine deaminase from mixtures containing other enzymes, for example, guanase or alcohol dehydrogenase.
 ...
PMID:Substrate- and product-affinity resins for adenosine deaminase obtained by immobilisation of adenosine and inosine via 2',3'-cyclic acetal derivatives. 64 8

A number of adenine nucleosides with exocyclic double bonds either at the 4',5' position in pentofuranosyl nucleosides or at the 5',6' position of hexofuranosyl nucleosides have been found to act as substrates for adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4) from calf intestinal mucosa. Most of the results obtained are contrary to the accepted minimal structural requirements for substrate activity. These nucleosides had either incorrect anomeric configurations or no hydroxyl group at C-5' or C-3' in the proper configuration; some compounds incorporated both structural changes. There is a possiblity that the unsaturated group has a special role in binding to the enzyme.
 ...
PMID:Unusual substrates for adenosine deaminase from calf intestinal mucosa. 68 43

Incubation of isolated rat epididymal fat cells is associated with the accumulation of adenosine in the incubation medium. To more clearly define the effect of adenosine on lipolysis, isolated rat epididymal adipocytes were studied with the perifusion system. Various combinations of epinephrine, adenosine, and adenosine deaminase were perifused through the adipocytes. Exogenous adenosine, 0.001-10.0 muM, had no discernible influence upon unstimulated lipolysis; but exogenous adenosine inhibited epinephrine-sensitive lipolysis in a concentration-dependent manner. Cells perifused with 0.3 muM epinephrine plus 0.001 muM adenosine did not show any impairment of the lipolytic response to 0.3 muM epinephrine alone. Adenosine, 0.01 muM, inhibited the response to epinephrine by 50%; response to 0.3 muM epinephrine plus 0.1 muM adenosine was similar to the basal rate. Perifusion with adenosine deaminase significantly increased basal lipolysis to 30% of the epinephrine response. Adenosine deaminase and epinephrine were synergistic in stimulating lipolysis to 180% of the response to epinephrine alone. Isolated fat cells were incubated for 30 min, and the cell-free used medium was perifused through fresh fat cells. Epinephrine in used medium was less effective in promoting lipolysis than epinephrine in fresh buffer. High-pressure liquid chromatography identified adenosine in the used medium. Bovine serum albumin possessed adenosine deaminase activity but accounted for negligible conversion of adenosine to inosine. Adenosine is shown to have a modulating effect upon basal and hormone-stimulated lipolysis in the perifusion system. Sufficient endogenous adenosine (<0.01 muM) is present to maximally affect basal lipolysis. Hormone-stimulated lipolysis, although inhibited somewhat by endogenous adenosine, requires the addition of exogenous adenosine for complete inhibition.
 ...
PMID:Perifusion of isolated rat adipose cells. Modulation of lipolysis by adenosine. 87 2

Adenosine deaminase (adenosine aminohydrolase EC 3.5.4.4) has been purified 468,000-fold from pooled human erythrocytes. The procedure developed was used to isolate the enzyme from up to 23 liters of packed erythrocytes at one time. An easily prepared affinity column bed material employing adenosine as the ligand was used as the final step in the purification. During elution from the affinity column there was approximately a 3:1 partition of adenosine deaminase between gel bed and column buffer. There was no apparent difference in the partitioning of unresolved or partially resolved preparations of the electrophoretically different forms of the enzyme on the affinity column. Gel filtration and electrophoresis on polyacrylamide gels of increasing concentration revealed no differences in the Mr of these electrophoretically different forms. The four bands resolved by electrophoresis of the different forms on polyacrylamide gels under nondenaturing conditions yielded a single band when electrophoresis was carried out in the presence of sodium dodecyl sulfate and 2-mercaptoethanol. Partially resolved preparations of the different electrophoretic forms of adenosine deaminase also gave rise to a single band of the same mobility when electrophoresed on polyacrylamide gels under these conditions. The band had the mobility of a protein of Mr of 36,000. This Mr is approximately the same as estimated for the nondenatured enzyme.
 ...
PMID:Purification of human erythrocyte adenosine deaminase by affinity column chromatography. 93 20

The red cell lysates of two children with severe combined immunodeficiency disease (SCID) exhibited a virtually total absence of adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4) when standard volumes were assayed. Under these conditions the parents exhibited depressed specific activity except for one mother, whose lysate showed a normal value for activity. Upon storage of the lysate at 4 degrees, a significant amount of activity appeared in one of the SCID children, and the activity of the heterozygous carriers was stimulated. With the use of a sensitive spectrophotometric assay based on conversion of inosine to uric acid, it was shown that the specific enzymatic activity in each of the SCID patients increased progressively as the volume of lysate assayed was lowered. With the smallest amount of lysate this specific activity was in the normal range. Similarly, the specific activity of each of the parents' lysates increased to the level of normal (or, in one case, about twice normal) as smaller volumes were assayed. The activity in the SCID patient was inhibitable by 2-fluoroadenosine and N6-methyladenosine, known competitive inhibitors of human red cell adenosine deaminase. The lysate from the SCID patient was also shown to inhibit adenosine deaminase partially purified from a normal individual. The results are interpreted in terms of a genetically programmed production of an adenosine deaminase inhibitor in at least one variant of the severe combined immunodeficiency disease.
 ...
PMID:A normal level of adenosine deaminase activity in the red cell lysates of carriers and patients with severe combined immunodeficiency disease. 106 Nov 4

A proportion of patients suffering from the autosomal recessive form of severe combined immunodeficiency have an inherited deficiency of adenosine deaminase (EC 3.5.4.4; adenosine aminohydrolase) (erythrocyte isoenzyme). We have, however, found residual adenosine deaminase activity in fibroblasts derived from four such patients. The enzyme responsible for this activity is biochemically homologous with the high-molecular-weight tissue isoenzyme of adenosine deaminase found in normal fibroblasts and tissues other than erythrocytes. The residual adenosine deaminase has an altered electrophoretic mobility, increased heat stability as compared to normals, and can be detected in fibroblasts of obligate heterozygotes. Our previous studies have indicated that the tissue and erythrocyte adenosine deaminase isoenzymes contain a common catalytic unit controlled by the gene affected in severe combined immunodeficiency with absent adenosine deaminase (erythrocyte isoenzyme). This residual adenosine deaminase therefore represents, most likely, a "mutant" enzyme in fibroblasts of patients with severe combined immunodeficiency. The data support the hypothesis that, in these patients, severe combined immunodeficiency is due to a mutation at the adenosine deaminase locus.
 ...
PMID:Characterization of residual enzyme activity in fibroblasts from patients with adenosine deaminase deficiency and combined immunodeficiency: evidence for a mutant enzyme. 106 Nov 19

Purine and pyrimidine metabolites were measured in erythrocytes, plasma, and urine of a 5-month-old infant with adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4) deficiency. Adenosine and adenine were measured using newly devised ion exchange separation techniques and a sensitive fluorescence assay. Plasma adenosine levels were increased, whereas adenosine was normal in erythrocytes and not detectable in urine. Increased amounts of adenine were found in erythrocytes and urine as well as in the plasma. Erythrocyte adenosine 5'-monophosphate and adenosine diphosphate concentrations were normal, but adenosine triphosphate content was greatly elevated. Because of the possibility of pyrimidine starvation, pyrimidine nucleotides (pyrimidine coenzymes) in erythrocytes and orotic acid in urine were measured. Pyrimidine nucleotide concentrations were normal, while orotic acid was not detected. These studies suggest that the immune deficiency associated with adenosine deaminase deficiency may be related to increased amounts of adenine, adenosine, or adenine nucleotides.
 ...
PMID:Purine metabolism in adenosine deaminase deficiency. 106 99

1. Erythrocyte adenosine deaminase (EC 3.5.4.4) and purine nucleoside (inosine) phosphorylase (EC 2.4.1.1) were measured in 33 healthy controls and 43 primary gouty subjects. Adenosine deaminase activity in controls and gouty subjects was 0.373 plus or minus 0.108 and 0.457 plus or minus 0.140 A unit per 5-10-3 ml packed red cells per h, respectively. The difference was statistically significant (P less than 0.01). Mean adenosine deaminase: inosine phosphorylase (X10) in primary gout was also significantly higher than in controls (P less than 0.05). Inosine phosphorylase activities in the two groups were not significantly different. 2. When gouty patients were divided into two groups according to weight, normal weight gouty subjects had a higher adenosine deaminase activity and an increased ration of adenosine deaminase to inosine phosphorylase when compared with overweight patients (P less than 0.10). In two control groups divided according to the percentage overweight, such differences were not found. In the case of two gouty groups divided according to the existence of gouty heredity, tophi or renal impairment, adenosine deaminase and inosine phosphorylase activity in the two groups were not significantly different. The possible biochemical role of adenosine deaminase activity in primary gout is discussed.
 ...
PMID:Erythrocyte adenosine deaminase and purine nucleoside phosphorylase activity in gout. 111 66


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>