Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The urinary excretion of adenosine-deaminase-binding protein, a constituent of the brush border of proximal renal tubule cells, has been investigated in 39 patients with disorders associated with malfunction of the renal tubules, and its excretion has been compared with that of two low molecular mass plasma proteins and an enzyme derived from renal tubular cells. None of the 36 patients with disorders associated with chronic renal tubular malfunction were found to be excreting significantly increased quantities of adenosine-deaminase-binding protein but 30 had increased excretion of retinol-binding protein, alpha 1-microglobulin, or N-acetyl-beta-D-glucosaminidase. Measurement of urinary adenosine-deaminase-binding protein may be useful in the assessment of acute renal tubular injuries but it is not of value in the detection of chronic renal tubular disorders.
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PMID:Absence of increased urinary excretion of adenosine-deaminase-binding protein by patients with chronic renal tubular malfunction. 172 56

Tests commonly used to assess the glomerular filtration rate (GFR) and to detect renal tubular damage are critically reviewed. Creatinine clearance which is frequently used for assessment of the GFR is prone to several errors. The plasma creatinine can be used to provide a rough guide but for reliable measurement of the GFR, 51Cr-EDTA clearance is recommended. Measurements of the urinary excretion of low molecular weight proteins, enzymes and kidney tissue proteins have been used to detect tubular damage. Of the low molecular weight proteins excreted, beta-2-microglobulin is unstable and measurement of retinol-binding protein or alpha-1-microglobulin is recommended for the detection of chronic renal tubular malfunction. Of the many enzymes that have been studied, urinary N-acetyl-beta-D-glucosaminidase or alanine aminopeptidase are recommended as being the most useful for the early detection of acute renal tubular damage. Among renal tissue proteins that have been measured in urine adenosine-deaminase-binding protein, a tubular brush border antigen appears to have considerable potential for providing early warning of renal allograft rejection.
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PMID:Assessment of renal function: selected developments. 218 56

A perfused rat liver was used to study the effects of 5-diazo-4-oxo-L-norvaline on lysosomal glycoprotein catabolism. Addition of this compound (1.0 mM) to the perfusate reduced activity of beta-aspartyl-N-acetylglucosylamine amidohydrolase by 99% in 1 h. Treated livers were unable to completely degrade endocytosed N-acetyl[14C]glucosamine-labeled asialo-alpha 1-acid glycoprotein as evidenced by a 50% reduction in radiolabeled serum glycoprotein secretion compared to controls. This decreased degradation was matched by a lysosomal accumulation of glycopeptides with the structure: GlcNAc beta(1-4)GlcNAc-Asn. The result suggested the presence of an unrecognized glycosidase in rat liver lysosomes, since this remnant was extended by one more GlcNAc residue than would have been expected after specific inactivation of the amidohydrolase. Such a novel enzyme would therefore catalyze cleavage of the N-acetylglucosamine residue at the reducing end of alpha 1-acid glycoprotein oligosaccharides only following removal of the linking Asn. The activity was then detected in lysosomal extracts by using intact asialo-biantennary oligosaccharides labeled with [3H] galactose or N-acetyl[14C]glucosamine residues as a substrate. To prevent simultaneous digestion of the material from its nonreducing end, beta-D-galactosidase in the enzyme extract was first inactivated with the irreversible active site-directed inhibitor, beta-D-galactopyranosylmethyl-p-nitrophenyltriazene. The observed di-N-acetylchitobiose cleaving activity worked optimally at pH 3.4 and was uniquely associated with the lysosomal fraction of the liver homogenate. The enzyme also cleaved triantennary chains and di-N-acetylchitobiose, but failed to hydrolyze substrates that had been reduced with NaBH4. The new glycosidase was well separated from N-acetyl-beta-D-glucosaminidase (assayed with p-nitrophenyl-beta-D-glucosaminide) by gel filtration chromatography and had an apparent molecular weight of 37,000. A similar enzyme that hydrolyzes di-N-acetylchitobiose had previously been found in extracts of human liver (Stirling, J. L. (1974) FEBS Lett. 39, 171-175).
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PMID:A di-N-acetylchitobiase activity is involved in the lysosomal catabolism of asparagine-linked glycoproteins in rat liver. 308 72

Endo-N-acetyl-beta-D-glucosaminidase (ENGase, EC 3.2.1.96) and peptide-N4-(N-acetyl-beta-D-glucosaminyl) asparagine amidase (PNGase, EC 3.5.1.52) activities were monitored during germination and postgerminative development in Raphanus sativus. The PNGase activity was found in dry seeds and its level was constant during germination and postgermination. The ENGase activity was first detected about 18 hr after the start of imbibition (HAI) and displayed a maximum level at 36 HAI. After 36 HAI the production of both enzymes was constant until days 4-5. Both enzymes displayed substrate specificities corresponding to the potential glycoprotein substrates found in plants. They are in agreement (i) with the hypothesis that ENGase and PNGase are at the origin of the production of 'unconjugated N-glycans' and (ii) with the possibility that protein activity could be regulated by the removal of N-glycans.
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PMID:Endo-N-acetyl-beta-D-glucosaminidase and peptide-N4-(N-acetyl-glucosaminyl) asparagine amidase activities during germination of Raphanus sativus. 757 49