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 post-nuclear fraction of rat heart tissue was fractionated by isopycnic zonal centrifugation in sucrose gradients, followed by differential centrifugation of the zonal fractions (rho-S fractionation). The distribution of 5 lysosomal acid hydrolases, a protease with neutral and alkaline activity and several marker enzymes for cell organelles (catalase, Ca2+-ATPase, cytochrome oxidase, glucose-6-phosphatase and muramidase) were studied. Three major lysosomal populations were described with equilibrium densities of 1.09, 1.17, and 1.23 gms cc-1 (omega2t = 1.54 X 10(11) rad2 sec-1), and a continuum in the size of these particles at the three different densities.
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PMID:Distribution of lysosome populations in rat cardiac tissue. 0 60

Urinary MDH, LDH, gamma-GT, LAP and muramidase levels were studied in 11 healthy persons with a wide age range and in 51 male Winstar rats weighing 300 to 400 g. Normal ranges of these urinary enzymes were determined and compared with the results of other authors.
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PMID:[Urinary enzyme levels in healthy human subjects and in rats (author's transl)]. 0 74

1. Lysozyme from eggs of the Dipterous Ceratitis capitata (Wiedeman) has been purified by ion-exchange chromatography and gel filtration and its physicochemical properties have been investigated. This is the first insect lysozyme characterized so far and it exhibits some properties different to those described for other animal lysozymes. 2. Lysozyme from the insect eggs has a molecular weight of about 23200 and a sedimentation coefficient of 2.4 S. Molecular weight determination by sodium dedecylsulphate gel electrophoresis indicates that the molecule consists of a single polypeptide chain. 3. This lysozyme preparation shows notable stability at acidic pH values and lability at alkline pH values. It shows a single optimum pH at about 6.5.4. Chitinase/muramidase specific activity ratio is around 350 times higher for the insect lysozyme than for the hen egg-white enzyme. 5. The amino-acid composition shows the presence of one tryptophan residue per molecule of enzyme. This fact differentiates the lysozyme from insect eggs from other animal and plant lysozymes. From the amino acid composition, the absorption coefficient and the partial specific volume are calculated. 6. Glycine is the N-terminal residue.
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PMID:Lysozyme from the insect Ceratitis capitata eggs. 1 78

A species of lysozyme (SE lysozyme) was purified from culture filtrate of Streptomyces erythraeus. The enzyme has a molecular weight of 18,500 as determined by ultracentrifugation. Its isoelectric point is 9.5, and it shows optimal activity at pH 4.0 with an optimal ionic strength of 0.1. Investigation of the substrate specificity showed SE lysozyme to be an N-acetyl-muramidase. The simplest product in the digest of cell walls of Micrococcus lysodeikticus was identified as a disaccharide, [GlcNAcbeta(1 leads to 4) MurNAc]. While S. aureus as well as M. lysodeikticus was lysed by this lysozyme, chitin and its derivatives were not.
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PMID:Purification and characterization of lysozyme produced by Streptomyces erythraeus. 2 74

Treatment of cells grown to exponential phase with 4% sodium dodecyl sulfate for 3 h at 100 degrees C resulted in solubilization of all cellular components except for peptidoglycan. In most strains, cells cultured in liquid gonococcal broth at pH 7.2 yielded a peptidoglycan composed primarily of N-acetylmuramic acid N-acetylglucosamine, alanine, glutamic acid, and diaminopimelic acid in a molar ratio of 1:1:2:1:1. The peptidoglycan in these cells accounted for 1 to 2% (dry weight) of the cells. However, in cells cultured at pH 6.0, the dry weight of peptidoglycan increased to 4 to 13%. Preliminary investigations indicated that the apparent increase in weight is strain dependent and is due in part to associated protein(s). Neisseria gonorrhoeae strain CS7 had elevated amounts of protein associated with the peptidoglycan regardless of growth pH. The peptidoglycan-protein complex could not be dissociated by additional extraction with sodium dodecyl sulfate, 10 M LiCl2, or ethylenediaminetetraacetate or by 7.5% polyacrylamide gel electrophoresis. The complex could be degraded by lysozyme, trypsin, chymotrypsin, Pronase B, and Chalaropsis sp. muramidase.
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PMID:Cell envelope of Neisseria gonorrhoeae CS7: peptidoglycan protein complex. 3 3

1. A glycol-chitin-splitting enzyme without lysozyme (muramidase) activity has been found in calf serum. The enzyme also degrades colloidal chitin and is thus a true chitinase, 1,4-beta-poly-N-acetylglucosaminidase, without exo-beta-N-acetylglucosaminidase effect. 2. The enzyme is purified 1000-fold by ion-exchange chromatography and gel filtration. Its optimal activity is between pH 1.5-2.0 with glycol chitin and between pH 3-6 in a rather broad optimum with colloidal chitin as substrate. The optimal stability of the enzyme is in the pH interval 3.0-6.5 when tested by incubation with glycol chitin at 50 degrees C for 60 min. The optimal temperature for the degradation of glycol chitin is 40 degrees C when assayed at pH 1.5 and 51 degrees C when assayed at pH 3.5. 3. The enzyme is activated by moderate heating at pH 6.5. The highest relative activity, 135% is reached after 45 min incubation at 30 degrees C, pH 5 or after 30 min at 40, pH 2.4. By incubation with small amounts of trypsin at pH 6.5 at 3m degrees C the enzyme was temporarily activated. 4. The isoelectric point, pH 5.3, and the molecular weight, 47,000 +/- 3,000 were determined by respectively isoelectric focusing and gel filtration. 5. The Michaelis-Menten constant, Km = 0.76 +/- 0.05 (S.E.) mg/ml, was measured with glycol chitin as substrate.
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PMID:Bovine serum chitinase. 4 11

Quantitative analyses of cell walls from Streptococcus mutans Ingbritt grown under carbohydrate limitation in the chemostat showed that growth conditions had no statistically significant effect on the composition of polysaccharide, peptidoglycan, or the proportion of polysaccharide in the cell wall. Lysis of cell wall preparations with a muramidase supported this conclusion and further indicated that there was little difference in their overall structure. In contrast, there was a consistent difference between the rates of lysis by this enzyme of organisms grown in 0.2% glucose and 0.5% glucose. Extremes of pH or dilution rate essentially did not influence the immunogenicity of type c antigen in whole organisms irrespective of whether the carbohydrate source was glucose or sucrose. However, differences were found in the immunogenicity of lipoteichoic acid under similar circumstances. The results indicated there was an inherent phenotypic stability in the cell walls of S. mutans Ingbritt despite changes in pH, generation time, and carbohydrate source, and that any changes that did occur were probably due to associated cell-surface components.
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PMID:Phenotypic stability of the cell wall of Streptococcus mutans Ingbritt grown under various conditions. 4 87

Earlier studies on fetal thymus suggested that certain of the large pyroninophilic cells found there might have a hemopoietic role, and it was decided to determine the nature of these cells using histochemical and immunohistochemical methods. Thymic tissue from aborted fetuses, stillbirths, and neonatal deaths was examined histochemically using methods for the detection of chloroacetate esterase, peroxidase, and pseudoperoxidase, and by staining techniques for mast cells and eosinophils. Tissue was also examined using the indirect immunoperoxidase method for the presence of hemoglobin A (HbA) and F (HbF), for lysozyme (muramidase) and immunoglobins alpha, mu, gamma, kappa, lambda. Positive staining to some degree was seen in cells in the connective tissue stroma using all methods, and the cells stained corresponded to one or another of the types of pyroninophilic cells present. The finding of large cells with positive chloroacetate esterase and antilysozyme indicates the presence of granulopoiesis. Similarly, the presence of large nucleated cells with pseudoperoxidase and anti-hemoglobin (A and F) staining indicates the presence of erythropoiesis. Plasma cells were present in small numbers.
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PMID:Evidence for significant hematopoiesis in the human thymus. 5 99

Monolayer and suspension cell cultures prepared from Hodgkin's disease tumors in the spleen were examined microscopically and by cytogenetics, tested for lymphocyte and monocyte cell surface properties, and assayed for enzymes by histochemical and spectrophotometric techniques. Hodgkin's disease monolayer cultures were composed of rapidly proliferating round and polygonal cells that were capable of propagation in vitro for an indefinite period of time. Abnormal aneuploid chromosomes were found in short-term Hodgkin's disease monolayers that had been passaged 16-20 times, and in established cell lines carried in culture longer than 3 yr and passaged more than 200 times. Cells fromHodgkin's disease monolayers contained lysozyme (muramidase), fluoride-resistant alpha naphthol acetate esterase, acid and alkaline phosphatase, and chymotrypsin-like activity. The monolayers did not exhibit specific cell surface markers or phagocytosis. Suspension cultures derived from Hodgkin's disease monolayers were composed of cells with aneuploid karyotypes and similar enzymes. The Hodgkin's disease suspension culture cells had surface receptors for complement and IgGFc, lacked surface or cytoplasmic immunoglobulin, and did not form Erosettes, react with an antithymocyte serum, nor exhibit phagocytosis. Normal monolayer culture cells, derived from adult spleen and human fetal spleen and thymus, were composed of spindle cells with a diploid number of chromosomes that could be carried for only a finite period of time in vitro. Normal cultured cells contained similar esterases and phosphatases, but were devoid of lysozyme and chymotrypsin-like activity. The morphologic, cytogenetic, cell surface, and enzymatic findings indicate that our Hodgkin's disease monolayer and suspension cultures are composed of cells with many properties suggesting an origin from monocytes (macrophages) rather than lymphocytes or fibroblasts. The presence of aneuploid karyotypes is consistent with a neoplastic origin and derivation from a malignant cell of Hodgkin's disease.
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PMID:Tissue culture studies in Hodgkin's disease: Morphologic, cytogenetic, cell surface, and enzymatic properties of cultures derived from splenic tumors. 6 93

Cytoplasmic immunoglobulins and muramidase (lysozyme) were demonstrated in formalin-fixed tissues by an immunoperoxidase procedure in 3 cases of Burkitt's lymphoma. The Burkitt cells were strongly positive with the full panel of monospecific antisera against human immunoglobulin components (kappa and lambda light chains, gamma, alpha and micron heavy chains). The 'starry-sky' macrophages were weakly positive with antimuramidase antiserum and strongly positive with the antisera against immunoglobulins, thus demonstrating their phagocytic and histiocytic nature. The reasons for the polyclonal increase in immunoglobulins are discussed.
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PMID:Immunohistochemical characterization of Burkitt's lymphoma. 9 95


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