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)

This work was undertaken to investigate whether or not antigen processing and presentation are important in channel catfish in vitro secondary immune responses elicited with structurally defined proteins, namely, pigeon heart cytochrome C (pCytC), hen egg lysozyme, and horse myoglobin. The use of in vitro antigen-pulsed and fixed B cells or monocytes as antigen presenting cells (APC) resulted in autologous peripheral blood leukocytes (PBL) responding with vigorous proliferation and antibody production in vitro. In addition, several long-term catfish monocyte lines have been found to function as efficient APC with autologous but not allogeneic responders. Subsequent separation of the responding PBL into sIg- (T-cell-enriched) and B (sIg+) cells subsets showed that both underwent proliferative responses to antigen-pulsed and fixed APC. Moreover, allogeneic cells used as APC were found to induce only strong mixed leukocyte reactions without specific in vitro antibody production. Initial attempts at identifying the immunogenic region(s) of the protein antigens for catfish indicated there are two such regions for pCytC, namely, peptides 66-80 and 81-104.
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PMID:Phylogeny of immune recognition: processing and presentation of structurally defined proteins in channel catfish immune responses. 166 58

Diabetes in the non-obese diabetic (NOD) mouse is a multigenic autoimmune disease and is possibly controlled by three recessive loci, including one that is linked to the major histocompatibility complex (MHC). The first external domain of the Class II MHC I-A beta chain in these mice is unique and has been suggested as being responsible for autoimmunity. The I-A alpha chain in these mice is I-A alpha d, and they lack the expression of I-E molecules. We have investigated immune responses to various Ir gene control antigens in NOD mice to determine the influence of the NOD Ia and particularly the I-A beta chain. We find that sheep insulin is highly immunogenic while other insulins are weakly immunogenic in these mice. Hen egg lysozyme, pigeon cytochrome C and the synthetic polypeptide Poly 18, Poly EYK(EYA)5 antigen produce good antibody responses. Apart from H-2d, NOD are the only mice where Poly 18 antigen is immunogenic. In these mice Poly 18 induced good T-cell proliferative response, which was inhibited by anti-Ia antibody, and the mice were able to respond to tyrosine-containing polypeptide Poly EYA but not to the phenylalanine-containing antigen Poly EFA. We also found that synthetic peptide 48-60 of the NOD I-A beta chain is highly immunogenic in syngeneic NOD mice both for T cells and B cells. Using an I-A beta chain-specific monoclonal antibody, we are able to prevent induction of diabetes when the antibody was administrated in prediabetic, young mice. Our results suggest that the immune response to various antigens and autoimmune diabetes in NOD mice is directly influenced by the I-A beta chain.
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PMID:Role of the first external domain of I-A beta chain in immune responses and diabetes in non-obese diabetic (NOD) mice. 170

The partial molar volumes of various compounds that model protein constituent groups, such as tripeptides (Gly-X-Gly, where X = Gly, Ala, Val, Leu, Ile, Pro, Met, His, Ser), homopeptides (Glyn, n = 3,4,5), and simple organic analogues of amino acid side chains (methanol, acetamide, propanamide, acetic acid, propanoic acid, n-butanamine, n-butanamine nitrate, n-propylguanidine nitrate, 4-methylphenol), have been determined in aqueous solution with a vibrational densimeter in the temperature range of 5-85 degrees C. The partial molar volumes of amino acid side chains and the peptide unit were estimated from the data obtained. Assuming additivity of component groups, the partial molar volumes of polypeptide chains of several proteins over a broad temperature range were calculated. The partial molar volume functions of four proteins (myoglobin, cytochrome C, ribonuclease A, lysozyme) were compared with those determined experimentally for the unfolded and native forms of these proteins. It has been shown that the average deviation of the calculated functions from the experimental ones does not exceed 3% over the temperature range studied.
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PMID:Partial molar volumes of polypeptides and their constituent groups in aqueous solution over a broad temperature range. 208 Dec 62

The selectivity of the renal reabsorption of proteins has been investigated by competition experiments in conscious rats. The animals were intravenously injected with increasing doses of proteins over a wide range of net charge and size, including lysozyme, cytochrome C, metallothionein, beta 2-microglobulin, retinol-binding protein, albumin and IgG. The urinary excretion of exogenous proteins injected concomitantly (human beta 2-microglobulin, retinol-binding protein, albumin and/or egg white lysozyme depending on the experiment) and of rat beta 2-microglobulin, albumin and IgG was determined with specific immunoassays. The results show that low molecular weight cationic proteins and low or high molecular weight anionic proteins can increase each other's urinary excretion. Several observations strongly suggest that these effects result from a competitive inhibition of renal uptake. The phenomenon is dose-related in most cases and, as evidenced by cytochrome C injection, transient, reproducible and saturable. In addition, the injected proteins induce a tubular type proteinuria irrespective of their net charge and size. In the case of cationic proteins, this finding excludes the possibility of an enhanced glomerular permeability due to a partial neutralization of the glomerular polyanion which, as demonstrated with protamine sulfate, entails a glomerular type proteinuria. These quantitative data on the mutual inhibition of renal uptake of a wide spectrum of specific proteins lead us to challenge the concept of charge- and size-selective tubular reabsorption of proteins, and to postulate that proteins filtered through the glomeruli are taken up by common tubular endocytotic sites irrespectively of their physicochemical features. As demonstrated by the ability of beta 2-microglobulin and IgG to inhibit the uptake of lysozyme, the affinity of a protein for reabsorption sites is not simply related to its size and net positive charge. Evidence is also presented that proteins, when administered intravenously at high doses, induce a lysosomal enzymuria most likely reflecting a stimulated exocytosis.
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PMID:The renal uptake of proteins: a nonselective process in conscious rats. 246 Jun 61

Superoxide formation and lysosomal enzyme liberation circulating neutrophils has been assessed in healthy subjects. Blood samples were obtained at 8:00, 14:00, and 20:00 o'clock. The formation of superoxide followed a circadian rythm. Lowest concentration was found a 14:00 hours (4.59 +/- 2.09 nM reduced cytochrome/10(6) neutrophils). No 24 hour variation of betaglucuronidase and lysozyme liberation was proven. The number of neutrophil receptors for formyl-methyonil-leucyl-phenyl-alamine (FMLP) at the same hours did not show any circadian variation. The circadian changes of the functional capacity of the neutrophils might be one of the mechanisms that could justify the 24 hour variation of symptomatology characteristic of some diseases.
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PMID:[Circadian variations in the production of superoxide and liberation of lysosomal enzymes of neutrophils in peripheral blood]. 253 12

Polycationic molecules were studied either for their ability to displace the binding of basic fibroblast growth factor (bFGF) to high- and low-affinity membrane interaction sites and/or to modulate bFGF-induced proliferation of fibroblasts. Heparin-binding polypeptides, such as polylysine, protamine, histones, and thrombin-displaced [125I]bFGF bound to bovine brain membrane receptors. The most displacing polypeptides were those with the strongest affinity to heparin. Two of these polypeptides, protamine and polylysine, inhibited (at 5 microM) by more than 90% the mitogenic effect induced by bFGF on Chinese hamster lung fibroblast cells (CCL39). At the same dose, no effect was observed with basic proteins that do not bind to heparin, such as cytochrome C and lysozyme. An interesting observation was that protamine at 1 microM potentiated by 1.5-fold the mitogenic activity of bFGF, while it acted as an inhibitor at higher concentration.
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PMID:Modulation of mitogenic activity and cellular binding of basic fibroblast growth factor by basic proteins. 272 69

Experimental investigations indicate that localized forms of staphylococcal, Pseudomonas aeruginosa and associated (Pseudomonas aeruginosa-staphylococcal) infection inhibit the lysozyme activity, cause disorders in the metabolism of P-450 cytochrome, free-radical and iron-containing liver proteins.
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PMID:[Indices of lysozyme activity and of liver metabolic function in staphylococcal and Pseudomonas aeruginosa infection]. 275 Jan 4

Dielectric measurements, as a function of hydration, are reported for collagen, cytochrome-c, elastin and lysozyme powders. The hydration dependence of the dispersion that occurs in the frequency range between 10 kHz and 10 GHz has been used to identify two classes of protein-bound water molecules (namely, rotationally hindered or unhindered), as well as the hydration level for the onset of an increasing protein flexibility. Such studies can aid an understanding of the relationship between enzyme activity and structural flexibility, and of hydration-induced changes in the structure and dynamics of protein structures.
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PMID:Dielectric studies of protein hydration and hydration-induced flexibility. 298 34

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

To study the effect of gentamicin on the renal uptake of proteins, Sprague-Dawley female rats were intravenously injected with solutions containing unlabeled human beta 2-microglobulin (beta 2-m), retinol-binding protein, and increasing amounts of gentamicin (from 0.063 up to 31.5 mg/kg). The concentrations of human proteins and that of endogenous beta 2-m, albumin, and IgG in the urine collected during the 2 hr following the injection were determined by immunoassays. Gentamicin transiently increased the urinary excretion of rat and human beta 2-m in a dose-dependent manner. The mean relative increase of rat beta 2-m excretion ranged from 2 at a gentamicin dose of 0.06 mg/kg up to 500 at a gentamicin dose of 31.5 mg/kg. By contrast, the urinary excretion of other proteins was only increased by a factor of 2 to 5 at the highest dose of gentamicin. The relative increase of the urinary excretion of proteins was positively correlated with the fractional reabsorption of the proteins by the rat kidney. The inhibitory effect of gentamicin on the renal uptake of protein was very similar to that observed in rats injected with polycationic proteins like lysozyme and cytochrome C. These observations, combined with the fact that gentamicin, like proteins, enters the tubular cell by adsorptive endocytosis, strongly suggest that this drug competes with proteins for common binding sites on the apical tubular membrane and for subsequent endocytosis. Furthermore, the iv injection of large amounts of gentamicin and polycationic proteins induces a lysosomal enzymuria which very likely is a manifestation of an increased exocytosis.
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PMID:Effects of gentamicin on the renal uptake of endogenous and exogenous protein in conscious rats. 352 31


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