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Chemical structure of the peptidoglycan of Vibrio parahaemolyticus A55 with special reference to the extent of interpeptide cross-linking.

The chemical structure of the cell wall peptidoglycan of Vibrio parahaemolyticus A55 was studied. Estimation of cross linkages between peptide subunits in the peptidoglycan by dinitrophenylation showed that about 30% of the total 2,6-diaminopimelic acid (A2pm) residues were involved in cross linkages. The presence of interpeptide bridges was also demonstrated by isolating bisdisaccharide peptide subunit dimers from Chalaropsis muramidase digests of the cell wall peptidoglycan by gel filtration followed by ion-exchange column chromatography, although most of the building blocks obtained were uncross-linked disaccharide peptide monomers. The chain length of a glycan moiety of the peptidoglycan obtained by treatment with the L-11 enzyme and gel filtration of the digest was also studied. The chain length varied from 7 to 44, but 30% of the glycan fragments had muramic acid at the reducing end and a chain length of 28 to 44. In conformity with the above structural study it was demonstrated that a particulate enzyme fraction obtained by differential centrifugation of a sonicated preparation of V. parahaemolyticus catalyzed a penicillin-sensitive transpeptidation reaction, using UDP-MurNAc-14C-pentapeptide and UDP-GlcNAc as substrates.

Amino Acids↗

The incidence and significance of pseudoparaproteins in a community hospital.

Pseudoparaproteins were observed in 129 (10.5%) of 1,229 high resolution protein electrophoretic fractionations of serum (N = 847), urine (N = 368), or cerebrospinal fluid (N = 14) performed in this laboratory during a 12-month period. The pseudoparaproteins identified in serum electrophoretic patterns included fibrinogen, C-reactive protein, hemoglobin-haptoglobin complex, elevated beta-globulins (transferrin and C3), lysozyme (muramidase), and an extended migration artifact. In the electrophoretic patterns of urine, the pseudoparaproteins consisted of nonspecific gamma zone bands of varying intensity. Gamma zone trace protein in the cerebrospinal fluid was often of sufficient intensity to cause potential confusion with oligoclonal bands. Awareness of the characteristic electrophoretic migration positions of these pseudoparaproteins helps to avoid unnecessary ancillary testing and expense.

Adult↗

Antibody response to an autogenous vaccine and serologic profile for Streptococcus suis capsular type 1/2.

An autogenous vaccine was developed, using sonicated bacteria, with a strain of Streptococcus suis capsular type 1/2. The objectives of this study were to evaluate the antibody response following vaccination and to assess the changes in antibody levels in pigs from a herd showing clinical signs of S. suis capsular type 1/2 infection in 6- to 8-week-old pigs. An enzyme-linked immunosorbent assay using the vaccine antigen was standardized. Results from a preliminary study involving 2 control and 4 vaccinated 4-week-old pigs indicated that all vaccinated pigs produced antibodies against 2 proteins of 34 and 43 kDa, respectively, and, in 3 out of 4 vaccinated pigs, against the 117-kDa muramidase-released protein. For the serologic profile, groups of 30 pigs from the infected herd were blood sampled at 2, 4, 6, 8, and 10 weeks of age. The lowest antibody level was observed between weeks 6 and 8, presumably corresponding to a decrease in maternal immunity. A marked increase was seen at 10 weeks of age, shortly after the onset of clinical signs in the herd. For the vaccination field trial, newly weaned, one-week-old piglets were divided into 2 groups of 200 piglets each (control and vaccinated); blood samples were collected from 36 piglets in each group at 2-week intervals for 12 weeks. A significant increase (P < 0.05) in antibody response was observed 4 weeks following vaccination and the level of antibodies stayed high until the end of the experiment. In the control group, the increase was only observed at 13 weeks of age, probably in response to a natural infection. The response to the vaccine varied considerably among pigs and was attributed, in part, to the levels of maternal antibodies at the time of vaccination. No outbreak of S. suis was observed in the control or vaccinated groups, so the protection conferred by the vaccine could not be evaluated.

Animals↗

Clonal distribution of an atypical MRP+, EF*, and suilysin+ phenotype of virulent Streptococcus suis serotype 2 strains in Brazil.

Streptococcus suis is considered one of the most important bacterial swine pathogens worldwide. The distribution of the 35 described serotypes in diseased animals may vary in different regions. Data regarding S. suis isolation from pigs in South America is not available. In the present study, 51 isolates of S. suis recovered in pure culture or as the predominant species from diseased animals in Brazil, were analyzed. These isolates were classified as serotypes 2 (58.8%), 3 (21.5%), 7 (13.7%), 1 (3.9%), and 14 (2%). Serotype 2 isolates were further studied for their production of virulence-related proteins muramidase-released protein (MRP), extracellular factor (EF), and suilysin. In addition, the genetic diversity was studied by randomly amplified polymorphic DNA. All but 1 of the serotype 2 isolates showed a clonal distribution of an atypical phenotype (MRP+, EF*, suilysin+), different from the known European (MRP+, EF+, suilysin+), and North American (MRPv, EF-, suilysin-), phenotypes.

Animals↗

[New method for the determination of anti-lactoferrin activity of microorganisms].

A new method for the determination of the antilactoferrin activity (ALfA) of microorganisms, based on the detection of lactoferrin by the enzyme immunoassay, is proposed. The new method widens the spectrum of microorganisms to be tested, makes it possible to detect lactoferrin inactivation by bacteria producing antagonistically active substances (muramidases, organic acids, hydrogen peroxide, etc.), increases the reliability of the determination of the ALfA antilactoferrin activity of microorganisms due to the increased accuracy of its quantitative characterization. Testing of the culture fluid for lactoferrin following the growth of microorganisms in a medium with this protein revealed the capacity to inactivate lactoferrin in bacteria (Escherichia coli, Salmonella sp.) and yeast-like fungi (Candida sp.), isolated from feces and clinical material, of persons with carrier states, dysbiotic disturbances and pyoinflammatory diseases.

Candida↗

Purification and properties of chitinase from cabbage.

Chitinase has been purified from the extract of cabbage through successive steps of ammonium sulfate fractionation, chromatofocusing and Sephadex G-75 gel filtration. By these steps, the purity of the enzyme increased by 93.3 fold and the recovery of the enzyme activity was 20%. The purified enzyme had an optimal pH of 5.0, an optimal temperature between 40 to 50 degrees C and a Km of 76 microM for hydrolysis of ethylene glycol chitin. The molecular weight of the enzyme determined from filtration through Sephadex G-75 was 30,000 daltons. Heavy metal ions, Hg2+ (0.5 mM) and Ag+(2.5 mM) significantly inhibited the activity of the enzyme. NBSI1 (1.0 mM), DNFB (0.5 mM) and PMSF (0.5 mM) completely inhibited the activity of the enzyme. The enzyme also showed muramidase activity for hydrolysis of Micrococcus lysodeikticus cell wall. The presence of chitinase in cabbage may function as a defense enzyme against potential pathogens.

Ammonium Sulfate↗

Prevention of streptococcal pharyngitis by anti-Streptococcus pyogenes bacteriocin-like inhibitory substances (BLIS) produced by Streptococcus salivarius.

BACKGROUND & OBJECTIVES: Streptococcus salivarius is a numerically prominent member of the human oral microbiota that produces a variety of bacteriocin-like inhibitory substances (BLIS) having in vitro inhibitory activity against S. pyogenes. Our previous studies of S. salivarius isolates from children using a deferred antagonism BLIS production (P)-typing scheme showed that the 9 per cent of children having large populations of P-type 677 S. salivarius experienced fewer S. pyogenes acquisitions than either the 11 per cent of children having predominant P-type 226 populations or the 60 per cent of children with largely non-inhibitory (P-type 000) S. salivarius. Amongst the other BLIS P-types detected were a number of strongly-inhibitory (P-type 777) S. salivarius. In the present study the inhibitory agents produced by prototype strains of P-types 226, 677 and 777 S. salivarius are compared. METHODS: The prototype BLIS-producing S. salivarius strains SN, 20P3, and K12 were isolated from tongue swabbings. BLIS P-typing was done using standard procedures. The BLIS molecules were purified and characterized. RESULTS: S. salivarius SN (P-type 226) produces a heat-labile muramidase. S. salivarius 20P3 (P-type 677) produces the 2315 Da lantibiotic salivaricin A and S. salivarius K12 (P-type 777) produces two lantibiotics; salivaricin A2 (2368 Da) and salivaricin B (2733 Da). INTERPRETATION & CONCLUSION: The P-type 777 S. salivarius strain produced salivaricin A2 and salivaricin B. The combined production of two anti-S. pyogenes BLIS activities by this strain indicates that it could be adopted as a colonizing strain in bacterial interference trials.

Amino Acid Sequence↗

Analysis of the murein of a Listeria monocytogenes EGD mutant lacking functional penicillin binding protein 5 (PBP5).

Cells of a mutant of Listeria monocytogenes lacking functional PBP5, an enzyme with DD-carboxypeptidase activity, make thicker cells walls. In this study we show that the muropeptide profile of the mutant, obtained after HPLC analysis of a muramidase digest of cell wall murein, differs from that for the wild type strain. The main differences embrace strongly reduced disaccharide-tripeptide content, strongly increased amounts of pentapeptide-containing muropeptides and a shift in profile from less cross-linked muropeptides (monomers, dimers) towards more highly cross-linked ones.

Cell Wall↗

[Hydrolysis of a Staphylococcus aureus cell wall peptidoglycan by 209 P lysoamidase].

Hydrolysis of Staphylococcus aureus 209 P cell wall peptidoglycan was accompanied by the liberation of 1.3 mol of C-terminal and 1.2 mol of N-terminal glycine per mole of Glu as well as of 0.5 mol of N-terminal and 0.3 mol of C-terminal alanine. Gel chromatography on Sephadex G-25, ion-exchange chromatography on QAE-Sephadex A-50 and paper electrophoresis of S. aureus peptidoglycan hydrolysates gave seven homogeneous fractions; these fractions were structurally defined. Lysoamidase hydrolyzed bonds Mur-Ala, Gly-Gly and Mur-GlcN in the peptidoglycan molecule. Hydrolysis of glycan chains was accompanied by the formation of large fragments, (GlcN-Mur)9 and (GlcN-Mur)28. The lytic effect of lysoamidase on S. aureus peptidoglycan is coupled with bacteriolytic enzymes of lysoamidase: acetmuramyl amidase, glycyl--glycine endopeptidase and acetyl--muramidase.

Amino Acid Sequence↗

Growth pattern of the murein sacculus of Escherichia coli.

The mechanism by which the murein sacculus of Escherichia coli is being enlarged during growth was investigated by pulse and pulse-chase labeling with [3H]diaminopimelic acid. Changes in the composition of the sacculus during aging were analyzed in detail by high performance liquid chromatography separation of the muropeptide subunits released after complete muramidase digestion. After pulses as short as 10 s, a group of novel phosphorylated muropeptides was detected. The kinetics of their appearance is consistent with these structures being derived from the undecaprenylphosphate-linked growing points of murein. A complex maturation process of murein took place including a rapid decay of pentapeptide side chains and a 10-fold increase in tripeptidyl moieties. In addition, the total degree of cross-linkage increased from 16 to 25%, partly due to a 3-fold increase in the formation of LD-A2pm-A2pm cross-links. In pulse-chase experiments the cross-linkage started to decrease after a maximum at about 35 min of chase. The kinetics in the distribution of the radioactivity among acceptor and donor part in the major cross-bridges Tetra-Tetra and Tetra-Tri differed from each other substantially, indicating that the latter structure is completely cleaved within three generations, whereas only 40% of Tetra-Tetra is cleaved during the same time. Furthermore, the attachment of the lipoprotein to murein was delayed by about one generation. It is proposed that these findings reflect an inside-to-outside growth mechanism of the murein sacculus of E. coli.

Chromatography, High Pressure Liquid↗

[Low-molecular cysteine protease inhibitors in the human palatal tonsil].

2 low-molecular cysteine-proteinase inhibitors were purified from human tonsillar tissues: an acid cysteine proteinase inhibitor (ACPI), and a neutral cysteine proteinase inhibitor (NCPI). Their biochemical and immunological characteristics appeared to be identical to those inhibitors which we have identified in other human tissues in previous studies (epidermis and spleen). An immunohistological analysis revealed in tonsillar squamous epithelium a strong and consistent immunoreactivity for both inhibitors. In the tonsillar lymphatic tissue, ACPI-immunoreactivity appeared to be a characteristic mainly of dendritic reticulum cells whereas a prominent NCPI-immunoreactivity was confined mostly for the histiocytic reticulum cells in lymphoid secondary follicles. We also compared the distribution of the 2 immunoreactive inhibitors with the immunohistology as revealed by antisera raised against keratin and muramidase. Limitations of the immunohistochemistry of cysteine proteinase inhibitors are discussed in the light of an extensive trial of various fixation procedures. We deem that proposal of Barrett (1984) for the nomenclature of cysteine proteinase inhibitors is appropriate. According to it the ACPI is the cystatin A, and the NCPI is the cystatin B.

Child↗

Eye parameters for the diagnosis of xerophthalmos.

The anatomic aspects of the lacrimal apparatus are reviewed in relation to tear production, discussing the concept of xerophthalmos, its etiology and tests for its diagnosis. The authors use two diagnostic tests which quantify the serous secretion (Schirmer's or Jones's tests) and demonstrate epithelium damage (fluorescein or rose Bengal dye test). In cases of presumed xerophthalmos, other tests such as determination of lactoferrin, muramidase, IgA, TISC/BUT, etc. may also be performed to confirm the diagnosis.

Endothelium, Corneal↗

[Multicentric reticulohistiocytosis: histochemical, histoenzymatic and immunocytochemical study].

Report of a case of multicentric reticulohistiocytosis with clinical, histopathologic, histochemical and immunohistochemical study. Neutral mucins and lipids were demonstrated in the cytoplasm of dermal histiocytes. The monocyte-histiocytic nature of the cells was shown by means of acid phosphatase, ATP-ase, muramidase and alpha-1-antitrypsin. Due to the immunohistochemical results, the relationship with Langerhans cells was rejected. No secretory activity of immunoglobulins was shown and the proliferation qualified as benign. The cells among the histiocytic population were typified as mature T lymphocytes.

Adult↗

[Complete clinical remission over 50 months of a patient with acute monocytic leukaemia (author's transl)].

A case of Schilling type pure acute monocytic leukaemia (M5 variety of the FAB classification) in a 38-year-old man is presented. The initial predominant clinical manifestation was an increase hypertrophic gingivitis. The cytological type was established according to the morphologic and cytochemical criteria currently in use. The patient was treated with daunomycin (60 mg/m2 one day) and ARA-C (100 mg/m2/12 hours for 7 days) in a 2-week interval cycles. Total remission was achieved after the fifth series. The series have been repeated over 4 years with intervals of up to 6 or 8 weeks. Complete haematologic remission has been constant, with normalization of the serum muramidase levels. A gingival biopsy taken at the same time has shown no evidence of leukaemic infiltration. The high incidence of malignancy in this cytological variety of acute leukaemia is pointed out; it is normally less sensitive to chemotherapy than the myeloid types. Remission has been total over a long period of time, which is exceptional in this type of leukaemia. The mean survival rate as recorded in the literature is only a little over 3 months.

Adult↗

[Bacteriolytic enzymes produced by actinomycetes. I. The physicochemical properties of the enzymes and the spectrum of their lytic action].

This review is devoted to the bacteriolytic enzymes produced by many actinomycetes, mainly by Streptomyces genus. The bacteriolytic enzymes hydrolyse the specific bonds in bacterial peptidoglycans and cause the solubilization of the cellular walls and the disintegration of the bacterial cells. Many of the enzymes are purified to the electrophoretic homogeneity. The actinomycetes form the endo-N-acetylmuramidases more often, then the endopeptidases follow according to the frequency of occurrence, while the amidases and endo-N-acetylglucosaminidases are met rather seldom among the streptomycete-producers. The known amidases and exo-enzymes which are also produced by some species of actinomycetes are not related to the lytic enzymes proper. Almost all known endopeptidases from streptomyces hydrolyse the bridge peptide bonds in which the carboxyl group of terminal D-alanyl of peptide chain is involved. The bacteriolytic spectra of the different muramidases differ from each other and essentially differ from the spectrum of the egg-white lysozyme. Some endomuramidases from streptomyces are able to hydrolyse streptococci and some other important from the practical point of view microorganisms resistant to the action of lysozyme.

Actinomycetales↗

The biochemistry of bacteriolysis: paradoxes, facts and myths.

Degradation of cell wall components of certain microbial species following phagocytosis by neutrophils and macrophages might involve the activation, by leucocyte cationic proteins, of the bacterial autolytic wall enzymes, leading to bacteriolysis. Lysozyme (a distinct cationic agent), which is the main muramidase present in leucocytes and in body fluids, might function not only as an enzyme but also as a potent activator of autolysis. Sulphated polyelectrolytes, proteolytic enzymes and oxygen radicals, which are released in inflammatory sites, might inactivate the autolytic wall enzymes, leading to the accumulation of peptidoglycan-polysaccharide complexes within macrophages. Activated macrophages are instrumental in initiating chronic inflammatory reactions. Undegraded microbial cell wall components also function as immunomodulators and as enhancers of non-specific resistance to infections and to malignancy.

Anions↗

Histiocytosis X in 9 children: clinical aspects and laboratory evaluations including an analysis of monocytopoiesis.

Nine children with histiocytosis X were observed. The course of the disease largely depended upon the degree of dissemination at the time of diagnosis. Bone and skin involvement healed completely with a relatively simple therapy using prednisone in combination either with vincristine or vinblastine. Complete or long lasting partial remissions could be achieved up to involvement of 4 organs. Three patients demonstrating histiocyte infiltrations in 5 organs died. They all were less than 2 years of age. Hyperproliferation of monocytopoiesis was present in all patients manifesting itself by a rise in the fraction of mononuclear phagocytes in bone marrow. This variation was paralleled by monocytosis in the peripheral blood in 5 of 7 cases. Serum muramidase levels were increased in 5 of 6 patients. However, there was no clearcut correlation to the degree of disease dissemination.

Adolescent↗

Malakoplakia in ulcerative colitis.

Classic malakoplakia was found in the colon of a patient with a 30-year history of proven ulcerative colitis. She had undergone total proctocolectomy after failure of medical treatment to control her illness. Immunoperoxidase studies showed immunoglobulins and muramidase within the malakoplakic histiocytes, and electron microscopy showed bacteria resembling Escherichia coli in the same cells. Immunologic studies on the patient showed an unusually high E coli antibody titer (1:512) in her serum and reduced numbers of circulating T-lymphocytes with reduced cytotoxic activity. This case shows the paradoxical rarity of malakoplakia in ulcerative colitis and reaffirms the presence of an immunologic defect that may be pathogenetically significant.

Antibodies, Bacterial↗