Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.1.3.5 (
5'-nucleotidase
)
3,167
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
The effect of repeated administration of allopurinol (50 mg.kg-1 48, 24, and 4 hours before analysis) on the activity of enzymes of degradation and resynthesis of adenine nucleotides was studied. The activity of
xanthine dehydrogenase
and xanthine oxidase was inhibited in the heart, liver and kidney and the activity of membrane-bound
5'-nucleotidase
was particularly elevated in the heart and brain, suggesting that membrane transport processes may be affected. The increase in the activity of hypoxanthine guanine phosphoribosyl transferase in the liver is indicative of a potential mechanism of positive action of allopurinol upon restoring the purine nucleotide store. The authors present their hypothesis on the mechanism of allopurinol action upon the metabolism of adenine nucleotides. The suggested mechanisms might become operative in protecting tissues against ischemia and reperfusion induced damage.
...
PMID:[Mechanisms of the effect of allopurinol on the metabolism of adenine nucleotides]. 191 98
5'-Nucleotidase which was found first in chicken liver and found to be located in cytosol was purified and characterized. This enzyme is termed cytosol
5'-nucleotidase
for convenience. Some properties of this enzyme are summarized in Table 7. (Table: see text) The specific activity of cytosol
5'-nucleotidase
in chicken liver cytosol is higher than that in rat liver cytosol. In response to a high protein diet the activity of cytosol
5'-nucleotidase
in chicken liver increased, concurrently with those of purine nucleoside phosphorylase and
xanthine dehydrogenase
. Of the three enzymes, the activity of cytosol
5'-nucleotidase
reached a maximum most rapidly. In rat liver, the activities of these three enzymes did not increase on administration of a high protein diet. From these results the principal physiological function of the cytosol
5'-nucleotidase
is assumed to be dephosphorylation of IMP as the first step in the pathway of uric acid formation from IMP, which is important in the elimination of nitrogen of amino acids and proteins in a uricotelic animal. An allosteric property of this enzyme is considered to be important for control of adenine and guanine nucleotide pools, especially in connection with the biosynthetic activity of the purine nucleotides in uricotelic animals.
...
PMID:Properties of cytosol 5'-nucleotidase and its role in purine nucleotide metabolism. 302 48
Soybean (Glycine max) and pea (Pisum sativum) differ in the transport of fixed nitrogen from nodules to shoots. The dominant nitrogen transport compounds for soybean are ureides, while amides dominate in pea. A possible enzymic basis for this difference was examined.The level of enzymes involved in the formation of the ureides allantoin and allantoic acid from inosine 5'-monophosphate (IMP) was compared in different tissues of pea and soybean. Two enzymes,
5'-nucleotidase
and uricase, from soybean nodules were found to be 50- and 25-fold higher, respectively, than the level found in pea nodules. Other purine catabolizing enzymes (purine nucleosidase,
xanthine dehydrogenase
, and allantoinase) were found to be at the same level in the two species. From comparison of enzyme activities in nodules with those from roots, stems, and leaves, two enzymes were found to be nodule specific, namely uricase and
xanthine dehydrogenase
. The level of enzymes found in the bacteroids indicated no significant contribution of Rhizobium japonicum purine catabolism in the overall formation of ureides in the soybean nodule. The presence in the nodules of purine nucleosidase and ribokinase activities makes a recirculation of the ribose moiety possible. In concert with phosphoribosylpyrophosphate synthetase, ribose becomes available for a new round of purine de novo synthesis, and thereby ureide formation.
...
PMID:Enzymes of ureide synthesis in pea and soybean. 1666 81
The appearance of enzymes involved in the formation of ureides, allantoin, and allantoic acid, from inosine 5'-monophosphate was analyzed in developing root nodules of soybean (Glycine max). Concomitant with development of effective nodules, a substantial increase in specific activities of the enzymes
5'-nucleotidase
(35-fold), purine nucleosidase (10-fold),
xanthine dehydrogenase
(25-fold), and uricase (200-fold), over root levels was observed. The specific activity of allantoinase remained constant during nodule development. With ineffective nodules the activities were generally lower than in effective nodules; however, the activities of
5'-nucleotidase
and allantoinase were 2-fold higher in ineffective nodules unable to synthesize leghemoglobin than in effective nodules. Since the expression of uricase has been shown to be regulated by oxygen (K Larsen, BU Jochimsen 1986 EMBO J 5: 15-19), the expression of the remaining enzymes in the purine catabolic pathway were tested in response to variations in O(2) concentration in sterile soybean callus tissue. Purine nucleosidase responded to this treatment, exhibiting a 4-fold increase in activity around 2% O(2). 5'-Nucleotidase,
xanthine dehydrogenase
, and allantoinase remained unaffected by variations in the O(2) concentration. Hence, the expression of two enzymes involved in ureide formation, purine nucleosidase and uricase, has been demonstrated to be influenced by O(2) concentration.
...
PMID:Appearance of purine-catabolizing enzymes in fix and fix root nodules on soybean and effect of oxygen on the expression of the enzymes in callus tissue. 1666 19