Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activities of urinary N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) were measured in 207 diabetic patients and 57 healthy controls, and the relationship of these enzymes to different stages of diabetic microangiopathy was studied. Diabetics with clinical proteinuria had higher urinary NAG and AAP (17.7 +/- 1.9 and 42.8 +/- 4.9 U/g creatinine, mean +/- SE, respectively) than healthy controls (1.8 +/- 0.1 and 10.0 +/- 0.4) or diabetics without proteinuria. Among diabetics without proteinuria, NAG excretion in those with retinopathy was slightly higher than in those without (6.4 +/- 0.5 v 5.4 +/- 0.4), and AAP in those with retinopathy was significantly higher than in those without (23.0 +/- 1.5 v 17.4 +/- 0.8, P less than 0.01). Urinary albumin measured by radioimmunoassay and lysozyme in diabetics with retinopathy but without proteinuria was higher than those without retinopathy (P less than 0.001 and P less than 0.01). The increase in albumin was the greatest in diabetics with long duration of the disease (greater than or equal to 8 years); however, NAG and AAP increased more significantly in those with high hemoglobin A1c than in patients with long duration.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparison of N-acetyl-beta-D-glucosaminidase and alanine aminopeptidase activities for evaluation of microangiopathy in diabetes mellitus. 288 Nov 86

Secretory immunoglobulin A, lactoferrin, lysozyme and tear specific pre-albumin were analyzed in stimulated tear fluid of 25 diabetic patients without retinopathy and in 29 diabetic patients with (pre) proliferative retinopathy using high performance liquid chromatography. Results were compared to those obtained in 26 healthy controls to determine the effect of diabetes mellitus on the exocrine function of the main lacrimal gland. Sodium dodecyl sulfate polyacrylamide gel electrophoresis onto minigels was performed on 20 tear samples for verification of high performance liquid chromatography fractions recorded. The mean total protein values in tear fluid (Bradford assay) of diabetics without retinopathy, with retinopathy and healthy controls did not differ significantly (mean in mg/ml +/- SD: 6.4 +/- 2.2, 5.9 +/- 2.0 and 5.7 +/- 1.7, respectively; Mann-Whitney; p > 0.02). High performance liquid chromatography showed an increased secretory immunoglobulin A and decreased peak 5 OD280 (+56% and -38%, respectively; p < 0.02) in patients without retinopathy, whereas in patients with retinopathy lysozyme was increased (+27%; p < 0.01) and tear specific pre-albumin and peak 5 OD280 decreased (-24% and -42%, respectively; p < 0.04), when compared to healthy controls. These inconsistent differences do not uniformly suggest an exocrine dysfunction of the main lacrimal gland in diabetic patients.
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PMID:Analysis of tear fluid proteins in insulin-dependent diabetes mellitus. 797 68

Protein glycation has been implicated in the aging process as well as the complications of diabetes (retinopathy, neuropathy, nephropathy, and atherosclerosis). The nitrogen substituents of Lys, Arg, and His residues and the N-terminus of proteins are known to be readily glycated. As the thiol group of Cys is a powerful nucleophile, we hypothesized that Cys residues should also be targets of glycation and that low molecular mass thiols may act as protective agents. In this study the role of thiol glycation, induced by dicarbonyls, in protein cross-link formation and damage prevention is examined. It is shown that incubation of creatine kinase with glyoxal results in protein cross-link formation, with this occurring concurrently with loss of thiol groups, enzyme inactivation, and formation of S-carboxymethylcysteine, a product of glyoxal adduction to Cys residues. Cross-links have also been detected between N-acetylcysteine and the Lys-rich protein histone H1, demonstrating the formation of thiol-glyoxal-amine cross-links. Mass spectrometry has been used to characterize some of these cross-links as 2-(alkylthio)acetamides. A range of low molecular mass thiols have been shown to inhibit dicarbonyl adduction to, and cross-linking of, the thiol-free protein lysozyme, consistent with these thiols being alternative (sacrificial) targets of glycation. Some of these thiols are more efficient modulators of glycation than established glycation inhibitors such as aminoguanidine. These data demonstrate that thiols are facile targets of glycation and that low molecular mass thiols are potent glycation inhibitors. These data may aid the design of therapeutic agents for the treatment of the complications of diabetes.
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PMID:Protein and low molecular mass thiols as targets and inhibitors of glycation reactions. 1717 81