Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Disulphide-rich proteins of widely differing functions were aligned with the aid of their half-cystinyl residues. This led to the grouping of ribonuclease, phospholipase A, lysozyme, snake venom toxins, bee and scorpion venom peptides, and the plant proteins potatoe carboxypeptidase inhibitor, ragweed pollen allergen, mistletoe toxins and pineapple sulfhydryl protease inhibitor into one super-family of proteins. Very few deletions/insertions were needed to effect alignment and probabilities were calculated for random occurrence of the matches that were found.
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PMID:Homology of functionally diverse proteins. 89 36

The nature of the abnormal elastotic materials seen in pingueculae and their insensitivity to elastase are poorly understood. The authors investigated their composition by immunoelectron microscopy using antibodies to elastic fiber components, serum and tissue components known to be associated with elastosis in other sites. The abnormal elastic fibers showed labeling for elastin, microfibrillar protein, and amyloid P where these components never co-localize normally, indicating the fibers are not simply immature but aberrant in organization. There was mild positivity for the serum protease inhibitor alpha-1 antitrypsin at the edges of the abnormal elastic tissue and marked positivity for lysozyme. The more superficial region of pingueculae had similar elastic constituents but no fiber formation and a paucity of elastic microfibrils. The subepithelial dense concretions showed strong staining for lysozyme, the first component to be identified in these aggregates. Amyloid P and lysozyme are characteristic components of dermal elastosis, postulated to have an inhibitory effect on elastolytic processes, indirectly affecting the control of elastogenesis. The greater prominence of nonfiber-forming aggregates in pingueculae may be related to their marked deficiency of elastic microfibrils compared with dermal elastoses. This difference speaks for more severe actinic cellular damage in the poorly protected conjunctival tissue.
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PMID:Elastic fiber components and protease inhibitors in pinguecula. 201 39

We investigated the effect of the extracellular protease of Serratia marcescens on human serum constituents such as immunoglobulins, fibronectin, alpha 1-protease inhibitor, alpha 2-macroglobulin, lysozyme, and transferrin. At a very low concentration of Serratia 56-kilodalton protease (56K protease), purified human plasma fibronectin was degraded rapidly into three structural domains or small fragments. Immunoglobulin G3 (IgG3) and IgA1 were also degraded within 30 min with 1 microgram of this protease per ml, more rapidly than their other subclass of IgG or IgA. alpha 1-Protease inhibitor, which did not inhibit the 56K protease, was degraded similarly by the protease. These events were demonstrated by fluorescence polarization and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The protease was considerably inhibited by human alpha 2-macroglobulin and chicken ovomacroglobulin. However, when there was a 2 M excess of ovomacroglobulin or a 4 M excess of alpha 2-macroglobulin over the 56K protease, about 25 or 40% proteolytic activity remained, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the protease degraded the alpha 2-macroglobulin extensively during prolonged incubation, which paralleled with regeneration of the protease activity. The protease also cleaved human lysozyme, although moderately. Human serum transferrin was degraded slightly, and human serum albumin was almost resistant to the 56K protease. The enzyme seemed to have no effect on reconstituted collagen, but it degraded rat tropocollagen and yielded fragments of beta and gamma chains by cleaving the intramolecular cross-links. Most of the above proteolysis by the 56K protease appears to result in a limited type of substrate specificity. Thus, the present study demonstrates that the protease is capable of degrading defense-oriented humoral proteins and tissue constituents. Furthermore, it is toxic to fibroblasts. These findings also clarified the possible role of Serratia protease as a virulence factor in the pathogenesis of serratial infections. We recently demonstrated this notion in vivo with rabbit cornea (R. Kamata et al., Ophthalmology 92:1452-1459, 1985).
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PMID:Degradation of protease inhibitors, immunoglobulins, and other serum proteins by Serratia protease and its toxicity to fibroblast in culture. 242 50

The effect of a protease inhibitor, leupeptin, on the presentation of hen egg lysozyme (HEL) to cloned T cells was investigated. We found that leupeptin-sensitive thiol proteases are apparently less involved when HEL is presented by the I-Ad molecule, than when it is presented by the I-Ed molecule. This selectivity was more of a function of the antigen than that of the Ia molecule because presentation of denatured or fragmented HEL was not sensitive to leupeptin whereas antigen presentation to a number of I-A-restricted T cell clones specific to other antigens was sensitive to leupeptin. These data demonstrate that the particular combination of major histocompatibility complex/nominal antigen recognized by a certain T cell clone may require processing of the antigen molecule through a certain group of proteases and that other combinations are independent of that particular processing pathway. Furthermore, there is a preference for a certain type of processing depending on the Ia molecule involved.
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PMID:Antigen-Ia interaction and the proteolytic processing of antigen: the structure of the antigen determines its restriction to the A or E molecule of the major histocompatibility complex. 242 26

The ability of pepstatin A, a protease inhibitor produced by Streptomyces testaceus, to elicit a number of responses by the human PMN has been studied. In lysozyme and beta-glucuronidase release, pepstatin A 10(-5)M is equivalent to the synthetic oligopeptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) 10(-7)M. In superoxide release, pepstatin A 10(-5)M produces 80% of that originated by FMLP 10(-7). After two minutes of incubation the superoxide release is important, there being no further increase after 10 minutes. Preincubation of the cells with cytochalasin B before stimulation with pepstatin A elicits a noticeable increase in O2- release. In chemotaxis, pepstatin A 10(-6) originates the same cell motility as FMLP 10(-9). Pepstatin A produces a cross deactivation with FMLP which adds further evidence to the hypothesis that both stimuli compete for the same receptor in the PMN.
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PMID:[Effects of pepstatin A on neutrophils; cross-deactivation with FMLP]. 298 85

We investigated the possibility that the functional impairment in neutrophil (PMN) chemotaxis which occurs during granulocyte concentrate storage might be due to autotoxicity from the release of neutrophil granule contents during storage. Preliminary experiments confirmed that the exposure of fresh PMNs to the intracellular contents of disrupted PMNs, decreased the subsequent chemotaxis of the fresh PMNs by 63 +/- 5 percent compared to control PMNs (p less than .01). Freshly harvested neutrophils were stored at low (2 X 10(7) PMN/ml) or high cell concentration (8 X 10(7) PMN/ml) with or without 15 mM sodium bicarbonate (in order to maintain pH). Prior to storage, and 24 and 48 hours after storage at 22 to 24 degrees C, we measured the cell and unit plasma content of lactate dehydrogenase (LDH), beta-glucuronidase, and lysozyme. These enzymes served as markers for cell lysis, and primary and specific neutrophil granule contents, respectively. We also measured the effect on neutrophil chemotaxis of adding a protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), to the storage medium. In addition, we measured the ability of PMNs to degranulate in response to an inflammatory stimulus before and after storage. The cell content of granule markers was largely unchanged during storage, except in the case of the units at a concentration of 8 X 10(7) PMN per ml stored without bicarbonate. In these units, lysozyme activity decreased by 15 +/- 7 percent after 48 hours of storage (p less than 0.02 vs. fresh PMNs). Likewise, the plasma content of LDH, beta-glucuronidase, and lysozyme increased significantly during storage, especially in units of high cell concentration stored without bicarbonate.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effect of storage on degranulation by human neutrophils. 398 10

Light microscopically the low molecular weight protease inhibitor (LMI) and lysozyme have both been demonstrated in the cytoplasm of serous cells of bronchial glands. By immunoelectron microscopy LMI was demonstrated in secretory granules of these serous cells. Many granules showed a peripheral or bean-shaped staining pattern, other granules were uniformly stained or not stained at all. In contrast to this latter finding, virtually all granules were found positive for the presence of lysozyme, suggesting that there is no association of LMI with lysozyme at the ultrastructural level.
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PMID:Ultrastructural localization of the low molecular weight protease inhibitor in human bronchial glands. 675 8

We prepared in rabbits an antiserum against low molecular weight protease inhibitor (LMI) purified from the sputum of patients with purulent bronchitis. Using this antiserum in an immunoperoxidase staining method we found that this inhibitor was located exclusively in the serous cells of the submucosal glands of human upper and lower airways. The inhibitor was localized also in serous cells of the sublingual and submandibular glands. In contrast, LMI could not be demonstrated in the serous cells of the parotid gland. In the tissues investigated a strong association between the localization of the protease inhibitor and lysozyme was observed. Our observations indicate that the inhibitor may be present together with lysozyme as a secretory product in the serous cell granules. The possible consequences of the coexistence of these two proteins in the defense mechanism of the respiratory tract is discussed.
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PMID:Localization of low molecular weight protease inhibitor in serous secretory cells of the respiratory tract. 678 37

Rabbit skeletal muscle calcium-dependent protease which requires millimolar Ca2+ concentration for activity is a dimer composed of Mr = 73,000 and 30,000 subunits. The subunit structure has been confirmed by co-elution of the two polypeptide bands on Sephadex G-200 chromatography, and by cross-linking the enzyme with dimethyl suberimidate followed by sodium dodecyl sulfate-disc gel electrophoresis. Preincubation of the enzyme with p-chloromercuribenzoate prior to nondenaturing electrophoresis resulted in dissociation of the subunits. The rabbit muscle calcium-dependent protease was rapidly inactivated when incubated in the presence of 6 mM Ca2+. The half-life of protease activity at 30 degrees C was independent of protease concentrations over the range of 0.005 to 0.272 mg/ml. The rate of inactivation was not affected by a 270-fold molar excess of a substrate protein succinylated lysozyme. Protease activity also rapidly decreased (t1/2 = 8.4 min) during the assay at 37 degrees C as determined by a decrease in linearity of the time course when substrate was limiting. The rate of protease inactivation during the assay was essentially the same as that observed when the protease was incubated at 37 degrees C in the absence of substrate (t1/2 = 7.2 min). The addition of either leupeptin or the calcium-dependent protease inhibitor protein from dog heart prevented protease inactivation. The protease displayed an increase in activity during the time course of autoproteolysis at 30 degrees C when activity was measured in the presence of 0.2 mM Ca2+ instead of 5 mM Ca2+.
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PMID:Rabbit skeletal muscle calcium-dependent protease requiring millimolar CA2+. Purification, subunit structure, and Ca2+-dependent autoproteolysis. 704 2

Increase in the weight of rat parotid glands, decrease in the protein concentration and the activity of alpha-amylase with simultaneous activation of the proteolytic enzymes (caseinolytic activity at pH 7.6, activity of cathepsins at pH 5.5) were observed in pyo-traumatic parotiditis. Local administration of the protease inhibitor (contrical) or intramuscular treatment with trypsin showed the positive medical effect--decrease of the gland weight, increase in the protein concentration and in the alpha-amylase activity together with lowering in the activity of proteinases. Intramuscular administration of antimicrobic enzymes (lysozyme, RNase, DNAase) did not affect the pyo-traumatic parotiditis. Application of proteolytic enzymes or their inhibitors is recommended for clinical treatment of parotidites.
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PMID:[Effect of a number of enzyme preparations on the course of experimental parotitis]. 745 17


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