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)

In order to probe the cause and nature of conformational changes induced by the chemical modification of amino groups in proteins, five acylated derivatives of ovalbumin namely 21% acetylated, 32% succinylated, 90% butyrated 92% succinylated, and 95% acetylated ovalbumins were prepared and their molecular and immunological properties were systematically investigated. As evidenced by the ultraviolet difference spectral, solvent perturbation, gel filtration, and viscosity data, acylation of the amino groups produced a definite conformational change in native ovalbumin whose extent was higher for higher degrees of chemical modification. The solvent pertubation data showed an exposure of 0.5 tryptophan and 3 tyrosine residues in native ovalbumin; the exposure increased to 1 tryptophan and about 5 tyrosine residues in the maximally modified proteins (i.e. 90% butyrated, 92% succinylated, and 95% acetylated ovalbumins). The Stokes radius (2.7 nm) and intrinsic viscosity (3.9 ml/g) of ovalbumin increased, respectively, to about 3.4 nm and 7.7 ml/g upon acylation of its 18 lysine residues; the intrinsic viscosity of 95% acetylated ovalbumin was 7.2 ml/g. The reduced viscosity of ovalbumin (4.2 ml/g) which remained unaltered on raising the pH to pH 11.2, increased to 7.9 ml/g on succinylation of 18 lysine residues. On raising the ionic strength from 0.15 to 1.0, the value decreased from 7.9 to 6.2 ml/g. These observations taken together with the fact that the intrinsic viscosities of 92% succinylated and 90% butyrated ovalbumins are identical, argue against the presently prevalent proposal that electrostatic effects alone are responsible for the disruption of native protein conformation during chemical modification. The immunological activity of ovalbumin towards rabbit anti-ovalbumin expectedly decreased with acylation of its amino groups but the three maximally modified ovalbumins retained 40% immunological activity. This taken along with the spectral and viscosity data showed substantial native structure (format) in the three maximally acylated derivatives. The rabbit antiserum against 95% acetylated ovalbumin did not cross-react with acetylated lysozyme and reacted poorly with the native and 92% succinylated ovalbumins suggesting that the antigenic make-up of the three maximally modified ovalbumins is different.
Biochim Biophys Acta 1978 Sep 26
PMID:Changes in conformation and immunological activity of ovalbumin during its modification with different acid anhydrides. 10 Dec 49

The germination rate of spores of C. difficile which is usually lower than 10(-5) is raised to about 5.10(-3) in presence of lysozyme. All spores are initiated by lysozyme when previously treated by sodium thioglycolate. These spores are indeed lysozyme-dependent for germination.
C R Acad Hebd Seances Acad Sci D 1978 Sep 25
PMID:[Initiation of germination of Clostridium difficile spores by lysozyme]. 10 45

The antibacterial activity of purified rabbit lysozyme was kinetically investigated at concentrations comparable to those in normal rabbit serum and plasma serum. The bactericidal capability, lysozyme content, and electrophoretic composition of "purified beta-lysin," fractionated from normal rabbit serum, were also examined. In contrast to the extensive antibacterial activity of dilute normal rabbit serum observed in vitro, rabbit lysozyme was only weakly bactericidal for Bacillus subtilis. Inhibition of lysozyme enzymatic and bactericidal activities in normal rabbit serum by antilysozyme immunoglobulin G slightly reduced the initial rate of killing. The addition of neutralizing antibody or histamine (another lysozyme inhibitor) to partially purified bactericidal serum fractions had no effect on killing kinetics. Increasing the ionic strength of reaction mixtures containing normal serum or partially purified bactericidal fractions to levels which completely inhibited lysozyme activity resulted in stimulation of their respective killing kinetics. The addition of inhibitors to normal rabbit plasma serum completely eliminated its bactericidal activity. With regard to the killing of B. subtilis by rabbit and human blood fractions, these analyses clearly demonstrated that (i) although lysozyme is not a significant antibacterial component of normal rabbit serum, it represents the principal factor in normal rabbit plasma serum; (ii) different primary bactericidal mechanisms which are not detectable by singlepoint analyses operate in the sera of different species; and (iii) purified beta-lysin isolated from normal rabbit serum by the classical procedure is a heterogenous mixture of components.
Infect Immun 1979 Sep
PMID:Role of rabbit lysozyme in in vitro serum and plasma serum bactericidal reactions against Bacillus subtilis. 11 89

The most common cyanobacterium contaminating drinking water systems in southwestern Pennsylvania is Schizothrix calcicola. Lipoplysaccharides (LPS) were isolated from this species by hot phenol-water extraction. The polysaccharide moiety was composed of glucosamine, galactose, glucose, mannose, xylose and rhamnose. The lipid A part contained beta-hydroxylauric, myristic, pentadecanoic, palmitic, beta-hydroxypalmitic, stearic, oleic, and linoleic acids. In contrast to many LPS isolated from Enterobacteriaceae, the dominant component was not beta-hydroxymyristic but beta-hydroxypalmitic acid. The LPS induced Limulus lysate gelation and Schwartzman reaction but was nontoxic to mice. The identity of LPS was verified by alkali and lysozyme treatment. The results suggest that S. calcicola is one of the principal sources of endotoxins in water systems using open finished-water reservoirs.
Appl Environ Microbiol 1979 Sep
PMID:Composition and biological properties of lipopolysaccharides isolated from Schizothrix calcicola (Ag.) Gomont (Cyanobacteria). 11 86

The galactose binding toxin (RCAII) from Ricinus communis was affinity-immobilised at varying densities on a polysaccharide matrix and reacted with glutaraldehyde. The critical density below which inter-molecular cross-links were not formed was determined. At this density RCAII was monoconjugated to lysozyme. This approach could serve as a prototype for enzyme-lectin and enzyme-antipolysaccharide antibody monoconjugation.
Biochim Biophys Acta 1979 Sep 29
PMID:Critical density for protein-protein monoconjugation on a polysaccharide matrix. 12 Oct 56

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.
Infect Immun 1975 Sep
PMID:Characterization of monkey peripheral neutrophil granules during infection. 17 Feb 8

Polymyxin B resistance in Bacillus subtilis can be suppressed by the synergistic action of lysozyme or of an analogous cell wall lytic activity released by B. subtilis spores during germination. Such a synergistic effect is probably due to partial cell-wall digestion by lysozyme that allows polymyxin to reach its site of action and is therefore distinct from the analogous synergistic effect described by other authors in Escherichia coli. In the latter case polymyxin B probably damaged the outer membrane, allowing lysozyme to reach and digest the cell wall.
Antimicrob Agents Chemother 1975 Sep
PMID:Mode of action of polymyxin B: physiological studies with Bacillus subtilis-resistant mutant. 17 Aug 57

The lysozyme level in tears of patients with HSV eye infection was examined and correlated with the clinical findings and presence of virus. The concentration of the enzyme in tears of patients during acute attack was 2.83 mg./ml. This value was significantly lower than that in tears from healthy controls (6.1 mg./ml.) and tears from the patient's healthy eye (4.46 mg./ml.). After termination of treatment with either IUDR or poly I:C, the lysozyme level rose to an average of 4.34 mg./ml. During the latent period of the disease the level increased (5.34 mg./ml.), but it remained lower than in healthy subjects who had never suffered from HSV eye infection. This may be an indicator of possible future recurrences.
Invest Ophthalmol Vis Sci 1977 Sep
PMID:Lysozyme tear level in patients with herpes simplex virus eye infection. 19 44

The thermal resistance of spore crops produced from each of two ileal loop-reactive strains of Clostridium perfringens type A was determined in two suspending vehicles consisting of 0.067 M (pH 7.0) phosphate buffer and a commercial beef gravy. D115.6 values obtained in buffer and enumerated after pretreatment with sodium ethylenediaminetetraacetate and recovery in plating medium containing lysozyme were two- to threefold greater than those obtained without this treatment. D115.6 values obtained with beef gravy were less than those obtained in buffer with or without lysozyme; however, the D98.9 and D104.4 values were 1.3 to 2 times greater than those obtained in buffer with lysozyme. The z values were within the ranges reported by previous investigators.
Appl Environ Microbiol 1977 Sep
PMID:Thermal inactivation of ileal loop-reactive Clostridium perfringens type A strains in phosphate buffer and beef gravy. 19 13

A neoplastic cell line (designated HuT11) has been established in continuous culture from an involved lymph node of a patient with Stage IIA Hodgkin's disease of the mixed cellularity type. The HuT11 line has been morphologically heterogeneous, consisting of mononucleate lymphoid-like cells, polygonal epithelioid cells, and mono-, bi-, and multinucleate giant cells. Four clones initiated from isolated binucleate giant cells of the HuT11 line also have been successfully established as continuous cell lines. The cloned lines have been morphologically distinct and more homogeneous, although typical giant cells have consistently appeared throughout the long-term culture of each. The HuT11 lines have grown as monolayers in McCoy's Medium 5A supplemented with 10% fetal calf serum, with generation times of 12 to 14 hr and high saturation densities. Cytogenetic studies showed that early and later passages of HuT11 cells were aneuploid, and all cell lines were successfully heterotransplanted in the hamster cheek pouch. Repeated indirect immunofluorescence examinations have shown each cell line to be negative for Epstein-Barr virus nuclear antigen. Indirect immunofluorescence tests in which monospecific immunoglobulins were used revealed positive membrane reactions for the gamma (heavy)-chain and kappa (light)-chain of human immunoglobulin G in approximately 20% of viable cells in each line; however, direct immunofluorescence with anti-human immunoglobulin G F(ab')2 reagent failed to confirm these reactions. Rosette tests for B- and T-lymphocyte and macrophage membrane receptors yielded negative results. All cell lines were strongly phagocytic for latex particles and neutral red dye. Cytochemical stains of the monolayers revealed abundant esterase, fluoride-resistant nonspecific esterase, acid phosphatase, and leucine aminopeptidase activities, while lysozyme assays were negative. Although some properties of the HuT11 lines have suggested a macrophage derivation, an undifferentiated lymphoid cell origin of the Hodgkin's neoplastic cell remains a possibility.
Cancer Res 1978 Sep
PMID:Cultural, morphological, cell membrane, enzymatic, and neoplastic properties of cell lines derived from a Hodgkin's disease lymph node. 20 94


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