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)

Weanling crossbred pigs (n = 216, 6.9 kg initially) were used in three 5-wk trials to evaluate the effect of supplemental biotin (0, 220, 440 and 880 ppb) and Cu (0, 200 and 400 ppm) on performance, hemoglobin concentrations, serum and liver Cu levels and immune response (humoral and cell-mediated). Feeding 200 ppm Cu increased growth rate (P less than .01) and feed intake (P less than .01) during the 5-wk trials; 400 ppm Cu depressed growth and feed intake after wk 2. Efficiency of feed utilization, however, was improved (P less than .05) when either 200 or 400 ppm Cu diets were fed. Whereas supplemental biotin generally did not affect pig performance, an interaction (P less than .01) during the first 2 wk was detected; ADG and feed intake were highest for 200 and 400 ppm Cu dietary levels in combination with the 440 and 880 ppb biotin levels. Hemoglobin concentration was depressed (P less than .01) when 400 ppm Cu was fed, and liver Cu levels were increased (P less than .01) 8- and 35-fold for pigs fed 200 and 400 ppm supplemental Cu, respectively. Although the magnitude of the immune response was small and inconsistent, diets containing 220 and 440 ppb biotin seemed to increase the immune response to sheep red blood cells, but 880 ppb biotin appeared to depress the response; there was no effect of biotin level on lysozyme titers. Addition of Cu to the diet tended to depress the immune response to lysozyme and phytohemagglutinin but did not affect sheep red blood cells.
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PMID:Effects of biotin and high copper levels on performance and immune response of weanling pigs. 276 3

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

Spectral changes of hemoproteins in the near ultraviolet region on binding to a ligand and on oxidation-reduction of the heme-iron were studied by computer-controlled spectrophotometry. Near ultraviolet difference spectra between the low spin and high spin forms of ferric hemoproteins were classified into three groups: Those showing two absorption peaks having maxima at around 285 and 295 nm, those showing a peak at around 275 nm, and those showing a peak at around 300 nm. No corresponding absorption peak was observed with model heme complexes of low molecular weight. The intensity of the peak in cyanide difference spectra of catalase and horseradish peroxidase in the near ultraviolet region was dependent on the concentration of added cyanide and paralleled the intensity of the spectral changes in the Soret region. The spectral changes in both the near ultraviolet and Soret regions developed within 6 ms after the addition of cyanide. Difference spectra between the reduced and oxidized forms of cytochrome c, cytochrome oxidase-cyanide complex, hemoglobin, and lactoperoxidase-cyanide complex showed a characteristic peak at around 285-290 nm. Various difference spectra of hemoglobin in the near ultraviolet region were also measured. The observed positions, shapes, combinations, and relative intensities of the peaks were compared with those of solvent perturbation difference spectra and pH difference spectra of proteins and aromatic amino acids and also with the diacetylchitobiose-induced difference spectrum of lysozyme. The kinds of aromatic amino acid residues possibly responsible for the observed difference peaks were discussed on the basis of the results of the comparison. Based on the results obtained, the common occurrence of a heme-linked functional response of the hemoprotein conformation was suggested.
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PMID:Heme-linked spectral changes of the protein moiety of hemoproteins in the near ultraviolet region. 298 98

We have prepared several silica-based cation-exchange materials that were suitable for the high-performance liquid chromatography of basic proteins. Two synthetic routes were examined. Central to both procedures was the adsorption of a low molecular weight polyamine. One method crosslinks the adsorbed polyamine with a multifunctional oxirane, which is then extensively derivatized with a monomeric cyclic anhydride. The second involves an adsorbed uncrosslinked polyethyleneimine layer which is reacted with polyacrylic anhydride, thereby crosslinking and imparting anionic character simultaneously. The resulting media prepared by either of these methods bound more than 40 mg of hemoglobin per gram of support depending on the reaction conditions. These cation-exchange stationary phases also exhibited good chromatographic performance, successfully resolving (horse heart) cytochrome c and lysozyme. Two of the more promising support materials were effectively used to isolate cytochrome c553 from a crude extract of cyanobacteria.
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PMID:Synthesis of cation-exchange stationary phases using an adsorbed polymeric coating. 301 12

Monkey pepsinogen A, monkey progastricsin, and porcine pepsinogen A were activated in the presence of two different protein substrates, namely, reduced and carboxymethylated lysozyme and hemoglobin. In each case, an extensive delay in activation was observed. The intermolecular activation reaction required for the generation of pepsin or gastricsin was strongly inhibited and this inhibition was essentially responsible for the delay. However, the intramolecular reaction required for the generation of the intermediate forms of the proenzymes was scarcely affected. The delay was longer at pH 3.0 than at pH 2.0. Irrespective of the delay in activation of pepsinogen, the digestion of substrates proceeded rapidly, evidence of the significant proteolytic activity of pepsinogen itself. Kinetic experiments demonstrated that pepsinogen changed from an enzymatically inactive species to an active species before the release of the activation segment. The proteolytic activity of the active pepsinogen was highest at pH 2.0, at 37 degrees C and the activity under these conditions was comparable to that of pepsin.
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PMID:Analysis of the activation of pepsinogen in the presence of protein substrates and estimation of the intrinsic proteolytic activity of pepsinogen. 313 9

The glycation (nonenzymatic glycosylation) of several proteins was studied in various buffers in order to assess the effects of buffering ions on the kinetics and specificity of glycation of protein. Incubation of RNase with glucose in phosphate buffer resulted in inactivation of the enzyme because of preferential modification of lysine residues in or near the active site. In contrast, in the cationic buffers, 3-(N-morpholino)propane-sulfonic acid and 3-(N-tris(hydroxymethyl)methyl-amino)-2-hydroxypropanesulfonic acid, the kinetics of glycation of RNase were decreased 2- to 3-fold, there was a decrease in glycation of active site versus peripheral lysines, and the enzyme was resistant to inactivation by glucose. The extent of Schiff base formation on RNAse was comparable in the three buffers, suggesting that phosphate, bound in the active site of RNase, catalyzed the Amadori rearrangement at active site lysines, leading to the enhanced rate of inactivation of the enzyme. Phosphate catalysis of glycation was concentration-dependent and could be mimicked by arsenate. Phosphate also stimulated the rate of glycation of other proteins, such as lysozyme, cytochrome c, albumin, and hemoglobin. As with RNase, phosphate affected the specificity of glycation of hemoglobin, resulting in increased glycation of amino-terminal valine versus intrachain lysine residues. 2,3-Diphosphoglycerate exerted similar effects on the glycation of hemoglobin, suggesting that inorganic and organic phosphates may play an important role in determining the kinetics and specificity of glycation of hemoglobin in the red cell. Overall, these studies establish that buffering ions or ligands can exert significant effects on the kinetics and specificity of glycation of proteins.
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PMID:Effect of phosphate on the kinetics and specificity of glycation of protein. 358 12

A greater proportion of Escherichia coli strains isolated from clinical extraintestinal infections produce alpha-hemolysin than do strains isolated from normal fecal flora. Proposed mechanisms to explain this observation have stressed the fact that hemolysis liberates hemoglobin, which may provide a nutritional boost for E coli growth. Alternatively, a cytolytic effect of hemolysin upon host neutrophils has been postulated. Our previous studies have suggested a third possibility: Human neutrophils incubated in the supernatant of an alpha-hemolysin-producing E coli strain produced a selective inhibition of chemotaxis toward C5a. Bacteria-free supernatants from 14 clinical strains of E coli were therefore evaluated for an ability to lyse sheep erythrocytes, alter human polymorphonuclear neutrophil (PMN) chemotaxin receptors, and affect release of PMN enzymes. Supernatants possessing hemolytic activity decreased the C5a receptor activity of human PMNs and increased the number of peptide receptors. A stimulation of secondary granule release, as evidenced by the release of PMN lysozyme, may account for the increased expression of peptide receptors. Perturbation of host defenses through a loss of neutrophil migratory function and secondary granule contents may allow for enhanced survival of E coli, which produce alpha-hemolysin.
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PMID:Escherichia coli and human neutrophils. Effect of bacterial supernatant with hemolysin activity upon chemotaxin receptors. 388 51

This paper reviews studies on thermostable proteins from thermophilic bacteria and on mutant proteins of human hemoglobin, tryptophan synthase alpha-subunit of E. coli, T4 phage lysozyme, and phage lambda repressor with respect to the role of the constituting amino acid residues in stabilization of conformation. The stability of a protein is easily affected by single amino acid substitutions, by which the protein undergoes change(s) of one or more of the following: a hydrogen bond, a salt bridge, a hydrophobic interaction, the volume of the residue, a disulfide bond, or the relative position of two aromatic rings.
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PMID:Effect of amino acid substitutions on conformational stability of a protein. 391 32

Intragastric administration to mice of solutions of crystalline T-2 toxin in a dose aqual to the LD50 or in doses from the 1/5 to 1/50 of the LD50 brought about a stable decrease in alkaline phosphatase activity and lysozyme concentration in blood serum. In addition, acute and subacute T-2 mycotoxicoses were characterized by a marked lowering of hemoglobin concentration, the total red cell and leukocyte counts (doses 1/5-1/20 of the LD50) and lymphosytes (doses 1/5-1/50 of the LD50) in the peripheral blood toward the end of experiments. Variation of the hematological and biochemical characteristics after administering the toxin in low doses was detected despite the absence of the clinical symptoms of intoxication. These characteristics are the most sensitive to the toxic action of T-2 toxin.
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PMID:[Toxicological characteristics of acute and subacute T-2 mycotoxicosis in mice]. 403 79

The acoustic absorption of protein solutions in the presence of phosphate and other buffering ions has been studied in the physiological pH range. Buffers containing hydroxyl residues as titratable groups cause a pronounced increase of protein sound absorption, which is attributed to relaxation processes of proton transfer reactions between buffer ions and accessible imidazole and alpha-amino groups of the protein surface. Amino group based buffers like Good's buffers do not induce additional sound absorption. Measurement of the ultrasonic absorption as a function of pH and of buffer concentration, and corresponding parameter fitting of the equation describing proton transfer relaxation processes has been used to evaluate equilibrium parameters. For the imidazole group of the amino acid histidine a pK value of 6.22 and for the imidazole group of the protein lysozyme a pK value of 5.71 have been determined. In hemoglobin the ligand-linked pK changes have been monitored by recording ultrasonic titration curves.
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PMID:Ultrasonic absorption studies of protein-buffer interactions. Determination of equilibrium parameters of titratable groups. 404 4


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