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)

A monoclonal antibody was used to characterize a serogroup 1 specific Legionella pneumophila Philadelphia strain 1 antigenic determinant. A quantitative fluorometric assay was developed to quantitate the antibody sites (2.7 +/- 0.4 X 10(5)) on Legionella bacteria and to determine the physico-chemical parameters of the antibody-antigen interaction (at 4 degrees C: delta G = -10.9 Kcal X mol-1, delta H = 1.7 Kcal X mol-1, delta S = 45 cal X K-1 X mol-1). The same method was used to study the modification or the removal of the antigen by chemical and enzymatic means (trypsin, papain, lysozyme, acetone, chloroform-methanol and Tris-EDTA); only Tris-EDTA extraction resulted in a significant decrease in antibody binding sites. Inhibition studies of the fluorescein-labelled antibody binding were performed with different sugars of which only L-fucosylamine was inhibitory, and with other monoclonal antibodies to Legionella pneumophila serogroup 1 in order to compare their fine specificity and affinity. The results indicate that the epitope recognized was an immunodominant carbohydrate including an aminodideoxyhexose and carried by the lipopolysaccharide.
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PMID:Partial characterization of a Legionella pneumophila serogroup 1 immunodominant antigenic determinant recognized by a monoclonal antibody. Legionella specific antigenic determinant. 243 83

We have studied protein acylation in neutrophils of guinea pigs using [3H]myristate. A large number of neutrophil proteins were acylated with exogenously added myristic acid. The myristoylation was detected on 110, 77, 56, 54, 52, 42, and 37 kDa proteins. These myristoylations were stronger in peripheral blood than in peritoneal cells. Myristic acid was found to be covalently linked by an amid bond to these proteins since the proteins were resistant to boiling, chloroform/methanol and hydroxylamine treatment. Most myristoylated proteins appeared to be associated with the membrane fraction, while some of the proteins such as 77 kDa one was distributed also in the cytoplasm and translocated from the cytoplasm to the plasma membrane by stimulation. Lysozyme was myristoylated in vitro by the N-hydroxysuccinimide ester of myristic acid. The myristoylated lysozyme had an ability to be associated with phospholipid liposomes, and the membrane-associated lysozyme became a substrate of the rat brain Ca2+- and phospholipid dependent protein kinase (protein kinase C). These results indicate that myristoylation in neutrophil proteins may have an important role in metabolic regulation through their membrane association.
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PMID:Myristoylation of neutrophil proteins and their biological characteristics. 285 65

Two rapid methods were evaluated for their extraction of plasmids from Clostridium perfringens. The first method involved lysis of 1 to 2 ml of C. perfringens culture by treatment with hyaluronidase, lysozyme, and sarcosyl. DNA, extracted with phenol-chloroform, was treated with RNase, boiled, and electrophoresed in a 1.2% agarose gel. The second method involved lysis of 2 ml of culture by lysozyme treatment and extraction with alkaline sodium dodecyl sulfate (SDS). Extracted DNA was treated with RNase, boiled, and electrophoresed in a 0.7% agarose gel. Of 57 strains of C. perfringens analyzed by both extraction procedures, 11 were shown to have plasmids by the alkaline SDS method which were missed by the phenol-chloroform extraction method. These new plasmids were of higher molecular mass and ranged up to 68 megadaltons. Use of the DNase inhibitor diethyl pyrocarbonate did not further improve the yield of plasmid DNA. An additional 159 isolates of C. perfringens screened by the alkaline SDS method revealed plasmids up to 80 megadaltons in mass and an overall plasmid carriage rate of 69%.
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PMID:Rapid extraction of plasmids from Clostridium perfringens. 287 Jun 80

A method for the isolation of DNA from mycobacteria propagated in vitro is described that utilizes organic solvents to extract lipoidal components from the outer membrane, and digestion with a protease (nagarse) and lysozyme to penetrate the cell wall. The mycobacterial cells were lysed by the addition of detergent and the DNA was purified by digestion with pronase, sequential phenol and chloroform extractions, and digestion with RNAase A. The isolated DNA, which was obtained in good yields, was of a relatively high Mr and could be readily digested by restriction endonucleases. By this method, the genomes of Mycobacterium avium, M. intracellulare, M. lepraemurium, 'M. lufu', M. marinum, M. phlei, M. scrofulaceum, M. smegmatis and M. tuberculosis were isolated and the restriction endonuclease digestion patterns analysed. Each species could be distinguished by the digestion patterns, indicating that this approach can be used for identifying mycobacterial species. This approach is also sufficiently sensitive to differentiate strains since we were able to distinguish two independently isolated strains of M. tuberculosis, H37 and H4. In addition, no evidence was obtained for the presence of methylcytosine residues in the sequences 5'.CCGG.3',5'.CCCGGG.3',5'.CC(A/T) GG.3' or for methyladenine at 5'.GATC.3' in the DNA of the nine mycobacterial species examined using pairs of restriction enzymes that recognize and cleave at the same nucleotide sequence but differ in their sensitivity to 5-methylcytosine or 6N-methyladenine.
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PMID:Isolation and restriction endonuclease analysis of mycobacterial DNA. 301 65

Coxiella burnetii, the etiological agent of Q fever, possesses immunomodulatory activity which positively and negatively regulates host immune responses. We wish to determine the Coxiella strain differences and the chemical nature of cellular components suppressing lymphocyte responsiveness. The bacterial components responsible for the immunomodulatory activity are associated with phase I cells. In its natural state, the phase I cell-associated, immunosuppressive complex (ISC) was resistant to chemical and enzymatic treatment. The ISC was inactivated and rendered accessible by chloroform-methanol (CM) (4:1) extraction of phase I cells which produced a CM residue (CMRI) and CM extract (CME). The suppressive components in either CMRI or CME did not induce ISC activity in the host when injected separately. Reconstitution of the CMRI with CME prior to injection produced the same pathological reactions characteristic of phase I cells. The CMRI suppressive component was sensitive to alkali, acid, periodate, lysozyme, and neuraminidase, but resistant to lipase and protease. An active component of CMRI was attached to the cell matrix by disulphide bonds. The amphipathic, lipophilic, CME suppressive component was ubiquitously distributed in procaryotes and eukaryotes because ISC activity of CMRI was regained after association with reagent-grade lipids and different CMEs. The ISC was expressed by phase I strains with smooth lipopolysaccharide (LPS) but not by phase II strains with rough LPS. Phase I heart valve strains carrying significant amounts of rough LPS did not express all of the biological properties of the ISC. The LPS molecule induced immune enhancement without immunosuppression. Thus, expression of the ISC showed strain variation and may be under genetic control. The complete details of the chemical composition and active components of the ISC should prove useful for biological-response-modification studies.
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PMID:Immune modulation by Coxiella burnetii: characterization of a phase I immunosuppressive complex differentially expressed among strains. 317 Nov 7

A method for detecting superoxide dismutase activity in individual colonies of Escherichia coli was developed. The assay involves the lysis of individual cells in colonies on filter papers by a series of lysozyme, chloroform, and freeze-thaw treatments. Filters are placed on agar plates to allow diffusion of cellular enzymes into a solid matrix. A nitroblue tetrazolium overlay is applied to detect superoxide dismutase activity. Colonies possessing activity produce achromatic zones against a dark Formazan background. The assay can detect the presence of superoxide dismutase and the relative amount of enzyme as well. This assay provides a method for screening a population of cells for mutants deficient in or overproducing superoxide dismutase.
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PMID:An assay for the detection of superoxide dismutase in individual Escherichia coli colonies. 328 15

A murine monoclonal antibody, VM-1, which binds to basal cells of normal human epidermis, reduces the ability of human squamous cell carcinoma cells (SCL-1) derived from the skin to attach and spread on collagen by about 50% and causes cell rounding. Similar effects have been previously shown using normal human keratinocytes. The attachment of cell lines derived from human lung squamous cell carcinomas (SW1271 and SW900), melanoma A375, glioblastoma 126, and fibrosarcoma HT1080 is also inhibited by this antibody. VM-1 antibody does not bind to normal human fibroblasts, benign nevus cells, or the human B-cell-derived line 8866. VM-1 antibody inhibits the growth of SCL-1 cells in vitro as measured by cell numbers and [3H]thymidine ([3H]TdR) incorporation. It is not cytolytic in the presence of complement as measured by 51Cr release. Repeated treatment of SCL-1 cells with VM-1 antibody significantly reduces the proportion of SCL-1 cells that attach to collagen. In addition, after treatment of SCL-1 cells with VM-1 antibody, several proteins can no longer be demonstrated by gel electrophoresis of the cell-free supernatant. The VM-1 antibody effect on attachment and spreading is partially reversed by pretreatment of the collagen surface with laminin and fibronectin, but not with the carbohydrates chondroitin-6-sulfate or hyaluronic acid or with the protein lysozyme. By fluorescence staining, the antigen recognized by VM-1 antibody is membrane-bound and Triton X-100 extractable. The VM-1 antigen is excluded from Bio-Sil TSK-400 and sediments at about 10.5 S. It has a covalent molecular weight on the order of 10(6). Proteinase K digestion produces VM-1 antibody reactive fragments, assumed to be polysaccharides, with a polydisperse molecular weight distribution in the range 5000 to 30,000. The VM-1 antigen is partially lost from solution on boiling and is no longer detectable in the aqueous or organic phase after chloroform-methanol extraction. The properties of the VM-1 antigen are consistent with those of a proteoglycan involved in attachment and spreading of keratinocytes and certain tumor cells on collagen.
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PMID:Inhibition of attachment and growth of tumor cells on collagen by a monoclonal antibody. 369 49

Extracts of Mycobacterium bovis ATCC 19210 were prepared from cells following treatment with acetone 3 times, ethyl alcohol-ether 3 times (1:1, v/v), and chloroform 3 times. Cells were dried and suspended in 0.05M Tris-HCl (pH 7.5) containing lysozyme (1 mg/50 mg of dried cells). One aliquot of the lysozyme extract was filter-sterilized and 1 aliquot of the lysozyme extract was autoclaved. Delayed-type hypersensitivity responses elicited in sensitized guinea pigs, using the filter-sterilized lysozyme extract, were significantly greater than responses elicited using the autoclaved lysozyme extract (P less than 0.01). The filter-sterilized lysozyme extract and a purified protein derivative (PPD) of M bovis, at equal protein concentrations, elicited comparable delayed-type hypersensitivity responses in sensitized guinea pigs. Significant differences were not detected between the mean enzyme-linked immunosorbent assay (ELISA) values on sera collected from calves before exposure to M bovis, using each of the lysozyme extracts or the M bovis PPD (P greater than 0.05). Significant differences were detected when ELISA values obtained using each of the antigens on post-exposure serum were compared with ELISA values on serum collected from calves before exposure to M bovis (P less than 0.01). Differences were not detected in mean ELISA values on sera from cattle collected 12 months after exposure to M bovis, using each of the lysozyme extracts or M bovis PPD (P greater than 0.05); however, 8 of 8 calves were identified as positive on ELISA, using the filter-sterilized lysozyme extract, 7 of 8 calves were positive, using M bovis PPD, and 7 of 8 calves were positive, using the autoclaved lysozyme extract.
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PMID:In vitro and in vivo evaluation of lysozyme extracts of virulent Mycobacterium bovis in guinea pigs and calves. 390 33

Small bacteriocin is a low-molecular-weight bacteriocin which is common in fast-growing rhizobia. As its activity could not be detected in chloroform-sterilized culture supernatants (P.R. Hirsch, J. Gen. Microbiol. 113:219-228, 1979), the bacteriocin could not be purified in order to study its mechanism of action. We report here that small is soluble in chloroform, an observation which led to effective and simple (partial) purification. Other properties of small are its low molecular weight, which is estimated to be between 700 and 1,500, its resistance to proteolytic enzymes, pectinase, and lysozyme, and its heat stability at pH 5.5 but not at pH 7.0. Its bactericidal action on exponentially growing sensitive cells was not detected until 11 h after its addition. The bactericidal action was preceded by inhibition of cell division. To determine whether small activity is required for nodulation or nitrogen fixation, a transposon Tn5-induced small-negative mutant was isolated. The observation that this strain formed normal, acetylene-reducing root nodules showed that small production is not a prerequisite for the formation of effective nodules.
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PMID:Bacteriocin small of fast-growing rhizobia is chloroform soluble and is not required for effective nodulation. 399 74

Bacteriophage phiX174 is an icosahedral phage which attaches to host cells without the aid of a complex tail assembly. When phiX174 was mixed with cell walls isolated from the bacterial host, the virions attached to the wall fragments and the phage deoxyribonucleic acid (DNA) was released. Attachment was prevented if the cell walls were treated with chloroform. Release of phage DNA, but not viral attachment, was prevented if the cell walls were incubated with lysozyme or if the virions were inactivated with formaldehyde. Treatment of the cell walls with lysozyme released structures which were of uniform size (6.5 by 25 nm). These structures attached phiX174 at the tip of one of its 12 vertices, but the viral DNA was not released. The virions attached to these structures were oriented with their fivefold axis of symmetry normal to the long axis of the structure. No virions were attached to these structures by more than one vertex. Freeze-etch preparations of phiX174 adsorbed to intact bacteria showed that the virions were submerged to one half their diameter into the host cell wall, and the fivefold axis of symmetry was normal to the cell surface. A second cell could not be attached to the outwardly facing vertex of the adsorbed phage and thus the phage could not cross-link two cells. When the virions were labeled with (3)H-leucine, purified, and adsorbed to Escherichia coli cells, about 15% of the radioactivity was recovered as low-molecular-weight material from spheroplasts formed by lysozyme-ethylenediaminetetraacetic acid. Other experiments revealed that about 7% of the total parental virus protein label could be recovered in newly formed progeny virus.
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PMID:Mode of host cell penetration by bacteriophage phi X174. 410 19


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