Amino-6-oxypurine

The bases found in RNA (ribonucleic acid) are the purine heterocyclics adenine (6-aminopurine) and guanine (2-amino-6-oxypurine) and their complementary pyrimidine bases uracil (2,4-dioxypyrimidine) and cytosine (2-oxy-4-aminopyrimidine), respectively (Section 1, Appendix). In RNA double-stranded duplexes adenine (A) base-pairs with uracil (U) via two hydrogen bonds (A=U) and guanine base-pairs with cytosine (C) via 3 hydrogen bonds (G=C). Adenine forms the nucleoside adenosine by an N-glycosidic link with the... 

Guanine (2-amino-6-oxypurine) Guanosine Deoxyguanosine Guanosine monophosphate (GMP) Deoxyguanosine monophosphate (dGMP)... 

Synonyms cas 73-40-5 2-amino-6-oxypurine 2-aminohypoxanthine mearlmaid Guanylic Acid Sodium Salt... 

Amino-6-oxypurine. See Guanine 2-Aminopentanaoic acid. See L-Norvaline... 

CAS 73-40-5 EINECS/ELINCS 200-799-8 Synonyms 2-Amino-1,7-dihydro-6H-purin-6-one 2-Amino-6-hydroxypurine 2-Aminohypoxanthine 2-Amino-6-oxypurine Cl 75170... 

DNA and RNA both contain the two substituted purines adenine (6-aminopurine) and guanine (2-amino-6-oxypurine). Small amounts of other bases including hypoxanthine and a variety of methylated purines and pyrimidines are found in certain types of RNA (page 299). 

The enzyme has been isolated from both eukaryotic and prokaryotic organisms [2] and functions in the purine salvage pathway [1,3]. Purine nucleoside phosphorylase isolated from human erythrocytes is specific for the 6-oxypurines and many of their analogs [4] while PNPs from other organisms vary in their specificity [5]. The human enzyme is a trimer with identical subunits and a total molecular mass of about 97,000 daltons [6,7]. Each subunit contains 289 amino acid residues. 

Amino and oxypurines couple at their 8-position a weakly alkaline medium is... 

Amino and oxypurines couple at their 8-position a weakly alkaline medium is necessary, so it seems likely that the reactive entity is an anion. ... 

A total of 6,629 consecutive serum urate determinations were monitored at two large hospitals in Durham, North Carolina. Hypouricemia was defined as a serum urate concentration of 2 mg/100 ml or less. Periodic checks showed that a value in this range was always more than two standard deviations below the mean of measurements made at either hospital on a given day. When significant hypouricemia was noted, the patient and his record was examined to determine the cause. If an obvious cause could not be ascertained by this method, another serum sample was obtained for measurement of uric acid, creatinine, phosphate, and salicylate, and a 24 hour urine specimen was collected in order to estimate uric acid, oxypurine, creatinine, phosphate, glucose, amino acid, and porphobilinogen excretion. 

Four of the subjects with neoplastic disease were studied in more detail (Table 3 and Table 4). In each subject, the ratio of urate creatinine found to be increased (Table 3). There was no evidence of renal glucosuria, hyperphosphaturia, or bicarbonate wasting, which would suggest a generalized defect of tubular transport in these patients (Table 4). One patient, however, patient W.G., had a generalized amino aciduria and another, patient A.H., had an increase in alanine excretion. Two of the patients, J.L. and W.G., with neoplastic disease and an increased Curate/ creatinine ratio had evidence of obstructive jaundice, with plasma bilirubin levels of 15 and 20 mg/100 ml, respectively. In these same two patients with extensive hepatic involvement there was also an increase in the urinary excretion of oxypurines (Table 4). 

Patient Diagnosis Tubular Reabsorption of Phosphate Urinary Glucose Urinary Amino Acids Urinary Oxypurines... 

The pathway of purine catabolism involves the hydrolysis of amino purines to oxypurines and ammonia. From the available evidence, this... 

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