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)

The human leukemic cell line LAMA-84 was established and characterized as an erythromegakaryocytic cell line. In the present study we show that these cells can differentiate in estrone-treated athymic mice and give rise to an erythroeosinophilic cell line (LAMA-87). This new cell line expressed glycoporin A, alpha beta and gamma globin chain mRNA but also eosinophilic peroxidase. Hemin slightly increased the total hemoglobin production of the cells and phorbol diester (TPA), dimethyl sulfoxide (DMSO) and sodium butyrate (SB) increased the expression of megakaryocytic markers (gpIIb/IIIa complex). When inoculated into non-treated athymic mice, LAMA-87 cells can differentiate to give rise to eosinomonocytic cells (LAMA-88). This new cell line expresses eosinophilic peroxidase, Luxol fast blue stain and synthesizes lysozyme. Depending on the inducer used, LAMA-88 can differentiate along a monocytic lineage (TPA, DMSO, SB and vitamin D3). These three LAMA cell lines should be useful in further studies of the molecular regulation of the pluripotent cell commitment and may provide a model for the understanding of human hematopoiesis.
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PMID:Selection and characterization of an erythroeosinophilic subclone (LAMA-87) and an eosinophilic subclone (LAMA-88) from the multipotential cell line LAMA-84. 799 72

Dehydroepiandrosterone (DHEA) and pregnenolone (PREG) were both metabolized by homogenates of brain, spleen, thymus, perianal skin, ventral skin, intestine, colon, coecum and muscle tissues from mice. The use of 2H-labeled substrates and of the twin ion technique of gas chromatography-mass spectrometry permitted identification of 7 alpha-hydroxy-DHEA and of 5-androstene-3 beta, 17 beta-diol as DHEA metabolites in digests of all tissues. The extent of PREG metabolism was much lower than for DHEA with all tissues but amounts of the main transformation product were sufficient in brain, spleen and ventral skin digests for identification with 7 alpha-hydroxy-PREG. Dimethylsulfoxide (DMSO) solutions of DHEA, PREG and of their 7-hydroxylated metabolites were injected at different doses and time intervals prior to proximal subcutaneous administration of a lysozyme antigen. Quantities of anti-lysozyme IgG were measured in the serum of treated mice and compared with that from sham-treated animals. Increase of anti-lysozyme IgG was obtained with DHEA and PREG (1 g/kg) when injected 2 h prior to lysozyme. Much lower doses (160 times less) of 7 alpha-hydroxy-DHEA and -PREG were also found to be significantly active when administered at the moment of lysozyme injection. A larger dose of 7 beta-hydroxy-DHEA (50 mg/kg) was necessary for a similar effect. These results suggest that in tissues where immune response takes place, the locally-produced 7-hydroxy metabolites of PREG and DHEA are involved in a process which may participate in the physiological regulation of the body's immune response.
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PMID:Pregnenolone and dehydroepiandrosterone as precursors of native 7-hydroxylated metabolites which increase the immune response in mice. 804 38

An influence of DMSO on lysozyme structure in solution was studied by fluorescence and optical rotary dispersion methods. Change in the protein structure was shown to proceed at DMSO concentration in water greater than 60% and result in an increase of the protein helicity. However, this structural state of lysozyme is similar to that of the unstructured peptides obtained by its complete proteolysis and is characterized by parameters of accessibility to solvent and mobility of their intrinsic chromophores. The data obtained evidenced that long range interactions have a little influence on the maintenance of the residual secondary structure of lysozyme in the presence of DMSO.
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PMID:[Denatured state of lysozyme in dimethyl sulfoxide]. 865 52

N alpha-Fmoc serine and its corresponding pentafluorophenyl ester were glycosylated with the 1,2-trans peracetates of the disaccharides galabiose and cellobiose. Complete stereoselectivity and 52-75% yields were obtained under boron trifluoride etherate promotion. Lower yields and loss of stereoselectivity were obtained when thioglycosides, trichloroacetimidates or glycosyl bromides were employed as glycosyl donors. The glycosylated building blocks were used in solid-phase synthesis of derivatives of a helper T cell immunogenic peptide consisting of amino acids 52-61 from hen-egg lysozyme. 1H-NMR spectroscopy in DMSO-d6 showed that the peptide moiety of the glycopeptides assumed random conformations which were not influenced by glycosylation at different positions.
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PMID:Solid-phase synthesis and conformational studies of helper T cell immunogenic peptides that carry carbohydrate haptens linked to serine. 879 Nov 56

The conformation of a chicken egg lysozyme molecule (dimensions, stoichiometry of its associates, and the degree of helicity) in DMSO was studied by small-angle neutron scattering, dynamic light scattering, and optical rotatory dispersion in the visible region of the spectrum. At high DMSO concentrations (70%), the protein was shown to exist as a dimer. The monomer molecules in the dimer adopt a partially unfolded conformation, with dimensions substantially greater than those in the native state and a high content of secondary structure (the degree of helicity is close to that of native lysozyme). This approach provides a unique possibility to assess the compactness of molecules in associates, which may be very useful in studying protein self-organization.
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PMID:[Partially unfolded state of lysozyme with a developed secondary structure in dimethylsulfoxide]. 897 70

Myxococcus xanthus is a Gram-negative, soil-dwelling bacterium with a complex life cycle which includes fruiting body formation and sporulation in response to starvation. This developmental process is slow, requiring a minimum of 24-48 h, and requires cells to be at high cell density on a solid surface. It is known that, in the absence of starvation, vegetatively growing cell suspensions can form 'glycerol spores' when exposed to high levels of glycerol, usually 0.5 M. The cells differentiate from rods to resistant spheres rapidly (2-4 h) and synchronously. We have found that the chromosomally encoded beta-lactamase of M. xanthus can be induced by numerous beta-lactam antibiotics as well as by non-specific inducers including glycine and many D-amino acids. In addition, D-cycloserine, phosphomycin, and hen egg-white lysozyme also induce beta-lactamase in this bacterium. Unexpectedly, agents which induce beta-lactamase can induce 'glycerol spores'; all of the agents tested which induce glycerol spores (glycerol, DMSO, ethylene glycol) also induce beta-lactamase. During the induction of sporulation, beta-lactamase activity increases, reaching a peak during the morphological transition from rod-shaped cells to spherical spores. These spores are viable and resistant to many treatments which disrupt vegetatively growing rods but are not as resistant as fruiting body spores. The concomitant induction of beta-lactamase and starvation-independent sporulation suggests that these processes share a common signal-transduction pathway. These results also suggest that starvation-independent sporulation may be an adaptation of cells in order to resist agents that damage peptidoglycan structure and therefore threaten cell survival.
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PMID:Starvation-independent sporulation in Myxococcus xanthus involves the pathway for beta-lactamase induction and provides a mechanism for competitive cell survival. 919 10

The 2H magnetic relaxation dispersion (NMRD) technique was used to characterize interactions of dimethyl sulfoxide (DMSO) with globular proteins. A difference NMRD experiment involving the N-acetylglucosamine trisaccharide inhibitor, demonstrated that the DMSO 2H NMRD profile in lysozyme solution is due to a single DMSO molecule bound in the active cleft, with a molecular order parameter of 0.47 +/- 0.05 and a residence time in the range 10 ns to 5 ms. With the aid of transverse 2H relaxation data, the upper bound of the residence time was further reduced to 100 microns. A 1H shift titration experiment was also performed, yielding a binding constant of 2.3 +/- 0.3 M-1 at 27 degrees C. In contrast to lysozyme, no DMSO dispersion was observed for bovine pancreatic trypsin inhibitor (BPTI), indicating that a stable DMSO-protein complex requires a cleft of appropriate geometry in addition to hydrogen-bond and hydrophobic interactions.
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PMID:Dimethyl sulfoxide binding to globular proteins: a nuclear magnetic relaxation dispersion study. 926 Feb 88

A partly folded state of hen egg-white lysozyme has been characterized in 50% DMSO. Low concentrations of DMSO (< 10%) have little effect on the overall folded conformation of lysozyme as seen from 1H NMR chemical shift dispersion. At increasing DMSO concentrations (> 10%) a cooperative transition of the structure to a new, partially folded state is observed. This transition is essentially complete by approximately 50% DMSO. NMR studies show an overall decrease in chemical shift dispersion with marked broadening of many resonances. A substantial number of backbone and side chain-side chain NOEs suggests the presence of secondary and tertiary interactions in the intermediate state. Tertiary organization of the aromatic residues is also demonstrated by enhanced near-UV circular dichroism and limited exposure of tryptophans as monitored by iodide quenching of fluorescence. The intermediate state exhibits enhanced binding to hydrophobic dyes. Further, the structural transition from this state to a largely unfolded conformation is cooperative. H/D exchange rates of several amide protons and four indole protons of tryptophans (W28, W108, W111, and W123), measured by refolding from 50% DMSO at different time intervals reveal that protection factors are high for the helical domain, whereas NH groups in the triple stranded antiparallel beta-sheet domain are largely solvent-exposed. An ordered hydrophobic core in the intermediate state comprising of helix A, helix B, and helix D is consistent with the high protection factors observed. The structured intermediate in 50% DMSO resembles the early kinetic intermediate observed in the refolding of hen egg white lysozyme, as well as a molten globule state of equine lysozyme at low pH. The results demonstrate the potential use of non-aqueous structure perturbing solvents like DMSO to stabilize partially folded conformations of proteins.
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PMID:Effects of organic solvents on protein structures: observation of a structured helical core in hen egg-white lysozyme in aqueous dimethylsulfoxide. 940 46

A new method for encapsulating a model protein, lysozyme into hydrophilic uncapped poly(d,l-lactic-co-glycolic acid) (PLGA) microspheres was developed using an oil/water (O/W) single emulsion technique. Lysozyme powder, which was prepared from lyophilization after adjusting a lysozyme solution pH at 3, was molecularly dissolved in a co-solvent system composed of dimethylsulfoxide (DMSO) and methylene chloride. The resulting organic solution containing PLGA was directly emulsified into an aqueous phase, and the organic solvent phase was extracted and evaporated. Various lysozyme-loaded PLGA microspheres having different morphologies were obtained depending on the relative mixing ratio of the two co-solvents used. In vitro release experiments indicated that an initial lysozyme release rate from the microspheres was mainly controlled by ionic interaction between basic amino acid residues in lysozyme and free carboxylate groups in PLGA polymer chain ends, which was probed by incubating the microspheres in a series of media having different NaCl concentrations. However, the protein release leveled off after about 15 days' incubation. To determine the reason for the protein 'no-release' from biodegradable microspheres, a systematic analysis was carried out. By separately adding 0.5 M NaCl, 5 M guanidine HCl, or 5 mM sodium dodecyl sulfate into the release media during the non-release period, it was possible to selectively identify a specific protein non-release mechanism: ionic interaction, non-covalent aggregation, and/or surface adsorption, respectively. It was found that non-covalent aggregation and surface adsorption of lysozyme within the microspheres were the main cause of no further release, whereas ionic interaction between degrading polymer and protein played an insignificant role in the later stage of the release period. The greater amount of additional lysozyme release by sodium dodecyl sulfate than by guanidine hydrochloride suggested that protein surface adsorption was a more critical factor in protein release than aggregation.
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PMID:A new preparation method for protein loaded poly(D, L-lactic-co-glycolic acid) microspheres and protein release mechanism study. 979 50

Gaseous CO2 was used as an antisolvent to induce the fractional precipitation of alkaline phosphatase, insulin, lysozyme, ribonuclease, trypsin, and their mixtures from dimethylsulfoxide (DMSO). Compressed CO2 was added continuously and isothermally to stationary DMSO solutions (gaseous antisolvent, GAS). Dissolution of CO2 was accompanied by a pronounced, pressure-dependent volumetric expansion of DMSO and a consequent reduction in solvent strength of DMSO towards dissolved proteins. View cell experiments were conducted to determine the pressures at which various proteins precipitate from DMSO. The solubility of each protein in CO2-expanded DMSO was different, illustrating the potential to separate and purify proteins using gaseous antisolvents. Polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS-PAGE) was used to quantify the separation of lysozyme from ribonuclease, alkaline phosphatase from insulin, and trypsin from catalase. Lysozyme biological activity assays were also performed to determine the composition of precipitates from DMSO initially containing lysozyme and ribonuclease. SDS-PAGE characterizations suggest that the composition and purity of solid-phase precipitated from a solution containing multiple proteins may be accurately controlled through the antisolvent's pressure. Insulin, lysozyme, ribonuclease, and trypsin precipitates recovered substantial amounts of biological activity upon redissolution in aqueous media. Alkaline phosphatase, however, was irreversibly denaturated. Vapor-phase antisolvents, which are easily separated and recovered from proteins and liquid solvents upon depressurization, appear to be a reliable and effective means of selectively precipitating proteins.
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PMID:Protein purification with vapor-phase carbon dioxide. 1009 36


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