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)

Rhesus monkey (Macaca mulatta) neutrophils were shown to contain the azurophilic granule maker enzymes myeloperoxidase and beta-glucuronidase but were deficient in the specific granule markers alkaline phosphatase (AKP) and lysozyme. Isopycnic centrifugation of leukocyte homogenates on linear sucrose gradients resulted in cosedimentation of myeloperoxidase and beta-glucuronidase with an equilibrium density of 1.18. After an intravenous inoculation of monkeys with Salmonella typhimurium AKP activity became marked, whereas that of beta-glucuronidase decreased and myeloperoxidase remained unchanged. Lysozyme was undetected throughout the course of the experiment, but was present in oil-induced peritoneal macrophages and peripheral mononuclear cells. The induced AKP exhibited partial latency and had an equilibrium density of 1.15. It is unclear, however, whether the induced AKP is associated with specific granules or cytoplasmic membranes. Hence, while these data are consistent with the presence of azurophilic granules in polymorphonuclear neutrophils from infected monkeys, the presence of specific granules in polymorphonuclear neutrophils of both uninfected and infected monkeys remains moot.
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PMID:Characterization of monkey peripheral neutrophil granules during infection. 17 Feb 8

The ingestion, bactericidal activity and metabolism of isolated mature neutrophil leucocytes during phagocytosis was studied in 17 patients with chronic granulocytic leukaemia (CGL) with the simultaneous use of normal controls. Seven patients had received no treatment and the others had been treated previously with Busulphan. The phagocytic indices for killed yeast cells did not differ from those of the controls. A diminished bactericidal activity against E. coli was found in nine CGL cases. The bactericidal capacity closely correlated with the degree of leucocytosis since patients with a WBC count of 90 000/mul or higher with one exception showed decreased bactericidal activities while patients with WBC counts below 90 000/mul with two exceptions showed normal bactericidal activities. The [I-14C]-glucose oxidation during phagocytosis was increased in four patients and decreased in three patients. Some correlation was found between abnormally high or low [I-14C]glucose oxidation and diminished bactericidal activity. The intracellular iodination reaction during phagocytosis was decreased in 10 cases while the extracellular iodination was increased in six cases and decreased in one case. The data for granulocyte iodination did not correlate with WBC count, bactericidal capacity or [I-14C]glucose oxidation. The time course for the bactericidal activity and granulocyte iodination seemed to deviate from the controls indicating a slow initial ingestion and/or degranulation phase. The CGL granulocyte content of myeloperoxidase was normal or increased, the lysozyme content was decreased in half of the cases while the amount of antibacterial cationic proteins was increased, normal or low. The present findings indicate a variety of abnormalities in the mature CGL granulocyte, which are not closely interrelated.
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PMID:Granulocyte function in chronic granulocytic leukaemia. I. Bactericidal and metabolic capabilities during phagocytosis in isolated granulocytes. 17 9

The functional significance of granule enzymes in polymorphonuclear leukocytes (PMN) is not fully understood because of the multiplicity of the enzymes and the rare occurrence of deficiencies in man. In order to select appropriate laboratory animals for functional studies, a phylogenetic comparison of enzyme levels in animal and human PMN was undertaken. Neutrophils were obtained from a variety of laboratory animals and man; the activities of alkaline phosphatase, lysozyme, myeloperoxidase, and beta-glucuronidase were determined by histochemical and analytical techniques. Marked interspecies differences in enzyme activity were found; many species were deficient in alkaline phosphatase or lysozyme. Differences in pH optima and metal requirements of alkaline phosphatase were not of sufficient magnitude to explain the variations of this enzyme.
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PMID:Granule enzymes of polymorphonuclear neutrophils: A phylogenetic comparison. 17 39

In 31 patients, covering a wide range of blood neutrophil counts and turnover rates, the plasma concentrations of myeloperoxidase and lactoferrin have been measured with radioimmunoassays and compared to neutrophil kinetic parameters, measured with DF32P-labeled neutrophils. It was found that the plasma concentrations of both proteins correlated significantly with the total number of neutrophils in the blood (TBGP=total blood granulocyte pool) as well as with the neutrophil turnover rate (GTR=granulocyte turnover rate), which is evidence that neutrophilic granulocytes are the main suppliers of myeloperoxidase and lactoferrin to the plasma. In contrast to the previously demonstrated better relationship between the GTR and plasma lysozyme, a protein also originating in neutrophil granules, both myeloperoxidase and lactoferrin correlated better with the TBGP. These differences may reflect differences in the mode of release of intragranular proteins from neutrophils to the plasma. The correlation of the plasma lactoferrin concentration with the TBGP was so good as to suggest its use in the clinical assessment of the TBGP.
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PMID:Plasma myeloperoxidase and lactoferrin measured by radioimmunoassay: relations to neutrophil kinetics. 17 93

The granulocytes of a patient with generalized pustular psoriasis (GPP) were found to have impaired ability to fix iodine after ingestion of yeast particles. Since hexose monophosphate shunt (HMS) activity was increased and the contents of 3 other lysosomal enzymes, beta-glucuronidase, N-acetyl-beta-glucosaminidase and lysozyme, were within normal range, the impaired iodination appeared to be due to a selective defect of myeloperoxidase (MPO) activity within the phagocytic cells. The deficient iodination was accompanied by a decreased intracellular killing of E. coli and C. albicans. Since hexose monophosphate shunt activity was enhanced and azide and cyanide inhibited the intracellular killing of E. coli only moderately, the patient's granulocytes may possess azide- and cyanide-resistant, MPO-independant microbicidal systems coupled to the oxidative metabolism. Assessment of granulocyte iodination and enzyme contents of the relatives of the patient revealed no hereditary transmission. Since GPP is characterized by the development of subcorneal pustules containing granulocytes, the MPO-deficiency may be the cause of or enhance the development of the disease.
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PMID:Function of granulocytes with deficient myeloperoxidase-mediated iodination in a patient with generalized pustular psoriasis. 17 20

Polymorphonuclear leukocytes of rabbits and chickens after homogenization in 0.34 M saccharose or after multiple freezing and thawing were subjected to differential centrifugation at 150, 800, 10 000 and 50 000 X g. In the fractions obtained in this manner, total bactericidal activity as well as the activity of myeloperoxidase (E.C. 1. 11. 1. 7), catalase (E.C. 1.11.1.6), lysozyme (E.C. 3.2.1.17), cathepsin D (E.C. 3.4.4.23) and E, beta-D-glucuronidase (E.C. 3.2.1.31) and acid phosphatase (E.C. 3.1.3.2) were determined. Antibacterial activity was found in all fractions from rabbit leukocytes, but only in the first fraction from chick leukocytes. The fractions from rabbit leukocytes contained all enzymes under study while in the fractions from chicken leukocytes the presence of myeloperoxidase, catalase or cathepsin E could not be demonstrated. The highest bactericidal activity was found in the second obtained from the homogenate or rabbit leukocytes. The highest specific activity of myeloperoxidase and homogenate of rabbit leukocytes. The highest specific activity of myeloperoxidase and the lowest activity of cathepsin D were also demonstrated in this fraction. The addition of pepstatin to rabbit leukocytes before their disintegration resulted in the inhibition of the activity of cathepsin D and E and in an increase in the specific activity of myeloperoxidase as well as in total bactericidal activity in the individual fractions. These results testify that microbicidal mechanisms of phagocytes from individual species may differ and when the structure of lysosomes is damaged, the liberated hydrolytic enzymes may gradually inactivate antibacterial substances.
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PMID:Localization of antibacterial activity and hydrolytic enzymes in subcellular fractions of rabbit and chicken polymorphonuclear leukocytes. 17 6

The changes in intraneutrophilic and plasma concentrations of the three antibacterial proteins lysozyme, lactoferrin, and myeloperoxidase were studied sequentially during acute bacterial infection in nine patients. Intraneutrophilic concentrations of the three proteins were decreased by more than 50% during the 1st week of infection, followed by a slow increase over the following 2 weeks. Nadir values coincided with maximal toxic granulation of the neutrophils. The data suggest that neutrophilic granulocytes are deficient during early bacterial infection, possibly because of deficient synthesis of antibacterial proteins in the bone marrow, and that neutrophil toxic granulation is the visual counterpart of this defect. The plasma concentrations of the three proteins showed considerable differences: whereas plasma lysozyme did not show any sequential changes, plasma myeloperoxidase was high at the start of infection and quickly decreased towards normal values, and plasma lactoferrin, high in the first samples, showed a secondary peak 1 week after onset of disease, before normalization was seen. These differences may result from differences in the signals are specific for the individual antibacterial protein and not for the different types of neutrophil granules.
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PMID:Neutrophilic granulocytes in acute bacterial infection. Sequential studies on lysozyme, myeloperoxidase and lactoferrin. 18 78

Phagocytosis begins with exocytosis--"extrarapid" discharge of bactericidal proteins and factors of permeability into the extracellular medium. A viewpoint was put forward on an "avalanch-like" character of the outcome of cationic proteins from leukocyte granules in inflammation and their participation in formation of a nonphagocytic type of resistance. In phagocytosis bacteria perish due to the myeloperoxidase system, lysozyme, lactoferin and nonenzymic cationic proteins. Hereditary deficit of the above-mentioned substances leads to intraleukocytic microbicidal insufficiency, a drastic decrease in the nonspecific resistance of the organism and to development of fatal granulomatous disease, and to other forms of pathology associated with genetic defects of the bactericidal systems of leukocytes.
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PMID:[Current trends in the study of phagocytosis and non-specific resistance]. 19 70

Human monocytes, lymphocytes, granulocytes, red cells, and platelets were completely separated from each other by zonal centrifugation on linear sucrose density gradient. The monocytes contained only one tenth the amount of myeloperoxidase, one half the amount of lysozyme, one half the amount of acid ,hosphatase, and one half the amount of beta-glucuronidase found in granulocytes; the monocytes contained no alkaline phosphatase or neutral protease. The lymphocyte fraction contained only acid phosphatase and beta-glucuronidase in amounts one half as much as in the monocytes. Fluctuations in enzyme levels of monocytes and granulocytes were noted following infection. In vitro, the isolated monocytes transformed into macrophages. The results suggest that lymphocytes, monocytes, and granulocytes may be linked biochemically in a differentiation sequence through sets of commonly shared enzymes as well as by groups of enzymes specific for each divergent cell line.
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PMID:Isolation of enzymatically homogeneous populations of human lymphocytes, monocytes, and granulocytes by zonal centrifugation. 20 68

Data on the role of oral lysozyme, ribonuclease, deoxyribonuclease and peroxidase in antimicrobial defense of the macroorganism are reviewed. The biochemical and physiological properties of the enzymes secreted by salivary glands and released from emigrating leukocytes are discussed. Spectra of antimicrobial action of the enzymes and participation of these enzymes in maintaining the stability of oral biocenosis are described as well as the regulation of these enzymatic activities and the pathogenetic significance of impairments in their secretion. The most perspective aspects of the problems discussed are outlined for further investigation.
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PMID:[Enzymatic mechanisms for antimicrobial protection of the oral cavity]. 20 88


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