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)

An endochitinase from centrifuged autolyzed cultures of Aspergillus nidulans has been purified 100 times. The enzyme has Mw 27,000, pI of 4.8 units, pH optimum around 5 pH units. It is unstable at temperature greater than 70 degrees C and does not have a cation requirement. It is inhibited by Hg2+, Cu2+, Ca2+ and Ag+ and it does not have muramidase activity. The enzyme depolymerizes chitin rapidly with production of high molecular weight polysaccharides, and then slowly degrades these with production of N,N'-diacetylchitobiose. The enzyme hydrolyzes N,N',N''-triacetylchitotriose with production of N,N'-diacetylchitobiose and N-acetylglucosamine and this hydrolysis is inhibited by other chitin oligomers and N-acetylglucosamine. This enzyme hydrolyzes in the same way the chitin obtained from the cell wall of Aspergillus nidulans.
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PMID:Endochitinase from Aspergillus nidulans implicated in the autolysis of its cell wall. 267 5

In athletes of high skills, a 5-percent decline of the body weight over 5 days by means of restricting water, fats and carbohydrates consumption was followed by reduced activity of ceruloplasmin and lysozyme of blood serum. After sauna attendance with a purpose of lessening the body weight, there was, along with a certain rise of the immunologic responsiveness of the body, a decrease in peroxidase activity, in the content of iron and copper in blood cells in the presence of appreciable losses of trace elements with sweat. Enrichment of the athletes' diets with trace elements combined with vitamins and bendasole hydrochloride in the course of sauna-induced body weight lessening not only prevented the negative alterations but also exerted a beneficial action on the function of certain body systems.
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PMID:[The effect of a rapid decrease in body weight and enriching rations with microelements on various functions of the athlete's body]. 281 9

Quantitative or analytical affinity chromatography has been successful primarily for the analysis of biologically determined macromolecular affinity relationships. Quantitative approaches are also needed to better characterize simpler, chemically defined immobilized ligands with potential for selective interaction with specific, predetermined protein surface groups. Protein interaction with immobilized metal is a rather selective and versatile, high-affinity adsorption technique for which there is little quantitative information. Using model protein interactions with immobilized Cu2+ ions, we have compared analytical frontal affinity chromatographic methods to a simple, nonchromatographic protocol for the rapid determination of quantitative affinity relationships. Values obtained for the equilibrium dissociation constant (Kd) and binding capacity (Lt) characterizing the interaction of lysozyme with immobilized Cu2+ were quite similar by frontal analysis (Kd = 37-42 X 10(-6) M; Lt = 6.8-7.4 X 10(-6) mol protein/ml gel) and by equilibrium binding analyses (Kd = 33 +/- 4.7 X 10(-6) M; Lt = 5.8-6.1 X 10(-6) mol protein/ml gel; 14 determinations). The interaction of ovalbumin with immobilized Cu2+ was characterized by an affinity (Kd = 4.2-4.8 X 10(-6) M) and capacity (Lt = 1.5-2.1 X 10(-6) mol protein/ml gel) which were also the same regardless of the method for affinity analysis. These values indicate that the total protein bound at saturation corresponds to as much as 17% of the total immobilized Cu2+ ions (approximately 40 X 10(-6) mol/ml gel). Thus, depending on the fraction of total immobilized Cu2+ available for interaction with a given protein (e.g., lysozyme), the number of individual immobilized ligands actively participating as well as those rendered unavailable upon individual protein binding events may be greater than 1. Linear Scatchard plots obtained for both lysozyme and ovalbumin (purified) suggest the presence of only a single type of immobilized Cu2+-protein interaction operative under the experimental conditions employed. However, Scatchard analyses of data obtained by the nonchromatographic equilibrium binding method also demonstrated the ability to simultaneously resolve the contribution of two components whose presence was predicted by frontal chromatography. Our results support the validity and utility of equilibrium binding data analyzed according to the equations outlined by Scatchard and others as an alternative to analytical chromatographic methods.
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PMID:Protein interaction with immobilized ligands: quantitative analyses of equilibrium partition data and comparison with analytical chromatographic approaches using immobilized metal affinity adsorbents. 338 9

The interaction of lysozyme, ovalbumin, bovine and pig serum albumins with Cu2+ immobilized on Chelating Sepharose Fast Flow or TSK gel chelate-5PW was studied by frontal analysis at various initial concentrations of these solutes. The chromatographic data so obtained served as a basis for evaluating some relevant affinity chromatography parameters by adapting previously reported equations to this system. The TSK-based adsorbent had lower adsorption capacity for all the model proteins compared to the agarose-based adsorbent, due primarily to its lower porosity which has a marked influence on the accessibility of the immobilized ligand to the proteins. On the other hand, the TSK-based adsorbent offers almost ideal conditions for studying adsorption equilibria under column chromatographic conditions. The adsorption capacity of these adsorbents for the model proteins ranges from about 0.6 to 7 mumol/ml, equivalent to 40-100 mg/ml, of adsorbent. The following equilibrium constants for the interaction of the proteins with immobilized Cu2+ were obtained: lysozyme, 1.8.10(4); ovalbumin, 1.5.0(5); BSA, 1.7.10(5); PSA, 3.7.10(5) and imidazole, 8.10(3) M-1. Despite the comparatively low affinity of imidazole for the adsorbent, it is an effective competing ligand, at comparatively high concentrations, for adsorbed proteins primarily because all adsorption sites are available to it. The results obtained suggest that about 1/3 to 1/2 of the potential adsorption sites on the model proteins are involved in forming coordination complexes with Cu2+ immobilized to covalently bound iminodiacetate groups on insoluble gel matrices.
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PMID:Interaction of proteins with immobilized Cu2+. Quantitation of adsorption capacity, adsorption isotherms and equilibrium constants by frontal analysis. 368 Apr 9

Hen eggs were used for the preparation of a multicomponent additive to milk mixtures for infants. Lysozyme hydrolysate containing up to 1 mg/ml lysozyme was obtained from egg albumen according to a specially developed technology. The hydrolysate was supplemented with vitamins C and PP. The egg yolk was used for the preparation of a yolk-fatty emulsion enriched with vitamin E, copper sulfate and ferrous lactate. Characteristics of the cow milk and milk mixtures supplemented with the multicomponent additive are maximally close to those of the human milk. The clinical trials of the lactic acid mixtures enriched with the multicomponent additive showed their high effectiveness in the nutrition of normal and sick infants. The technology of the additive production is simple; it is inexpensive and can be easily transported.
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PMID:[A multicomponent additive intended for preparing infant milk mixtures enriched with essential and protective factors]. 373 16

Lysozyme can cause unreliable results in sandwich ELISA procedures, since it strongly associates with proteins with low isoelectric points. As immunoglobulins have an isoelectric point of about 5, lysozyme may form a bridge between the IgG in the coat and the IgG of the enzyme-labeled antibodies. For reliable ELISA results, it is necessary either to remove lysozyme from samples or to mask it. Both Cu2+ ions and ovalbumin were very effective in masking lysozyme and thus avoiding its linkage to immunoglobulins. Ovalbumin was not always as effective as Cu2+ ions because in test samples other proteins with high isoelectric points may be present which may compete with lysozyme for association with ovalbumin.
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PMID:Interference of lysozyme in the sandwich enzyme-linked immunosorbent assay (ELISA). 389 63

Phagocytosis-stimulating factor (PSF) was purified by copper chelate chromatography and characterized in comparison with basic proteins in the granule of polymorphonuclear neutrophils. By copper chelate chromatography, PSF was eluted at pH 3.7; whereas cationic protein, lysozyme, and lactoferrin were eluted at pH 5.6, 5.1, and 4.0, respectively. Purified PSF has an approximate molecular weight of 16,000 and an isoelectric point at 8.7, which differ from those of basic proteins, such as cationic protein, lysozyme, and lactoferrin. Anionic substances such as DNA and heparin did not influence the phagocytosis-stimulating activity of PSF, whereas that of the granule basic protein fraction from resting polymorphonuclear neutrophils was abolished. PSF had little bactericidal activity against Escherichia coli and Staphylococcus aureus, whereas the granule basic protein fraction from resting PMNs had strong bactericidal activity against E. coli and weak activity against S. aureus. These results indicate that PSF is a basic protein which is distinguishable from cationic protein, lysozyme, and lactoferrin.
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PMID:Purification and characterization of a phagocytosis-stimulating factor from phagocytosing polymorphonuclear neutrophils: comparison with granule basic proteins. 399 49

Manganese is accumulated in Bacillus subtilis by a highly specific active transport system. This trace element "pump" is insensitive to added magnesium or calcium and preferentially accumulates manganese in the presence of cobalt, iron, and copper. Manganese uptake in B. subtilis is inhibited by cyanide, azide, pentachlorophenol, and m-chlorophenyl carbonylcyanide hydrazone. The uptake of manganese follows Michaelis-Menten kinetics, and the net accumulation of manganese is regulated by increasing the V(max) after exposure to manganese-starvation conditions and by decreasing the V(max) for manganese uptake during growth in excess manganese. The K(m) remains constant during these regulatory changes in V(max). Manganese accumulated during growth is exchangeable for exogenous manganese and can be released from the cells by toluene (which causes leakage but not lysis) or by lysis with lysozyme. Two stages can be distinguished with regard to intracellular manganese during the process of growth and sporulation. During logarithmic growth, B. subtilis maintains a relatively constant internal manganese content, which is a function of the external manganese concentration following approximately a Langmuir adsorption isotherm. At the end of log phase, net accumulation of manganese slows. A second phase of net manganese accumulation begins at about the same time during sporulation as the accumulation of calcium begins. The manganese accumulated during growth and early sporulation is exchangeable and therefore relatively "free"; intracellular manganese is converted later during sporulation into a bound form that cannot be released by toluene or lysozyme.
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PMID:Manganese transport in Bacillus subtilis W23 during growth and sporulation. 463

The particulate hydrogenase of Vibrio succinogenes is solubilized during treatment of cell envelopes at pH 11.0. Alkali-solubilized enzyme requires sulfhydryl compounds for activity. At neutral pH, soluble enzyme is reincorporated into alkalitreated cell envelopes and no longer requires an additional activator. In the present study, cell envelopes prepared by lysing cells with ethylenediaminetetraacetic acid plus lysozyme (EDTA-lysozyme) were used to determine the chemical composition of cell envelopes and derived pH 11.0 soluble and insoluble fractions and to investigate some properties of the binding and activation of alkali-solubilized hydrogenase. Lysis with EDTA-lysozyme resulted in the formation of spheroplast ghosts. The derived cell envelopes contained 61% protein, 3% ash, 23% lipid, and 1% phosphorus. The alkali-treated cell envelopes contained 50% protein, 2% ash, 24% lipid, and 1% phosphorus. The ash from cell envelopes and alkali-treated cell envelopes was rich in iron and phosphorus and also contained calcium, copper, magnesium, sodium, and zinc. Virtually all of the weight of the ashed samples was accounted for by the oxides of these metals. Since the reconstitution of particulate hydrogenase was achieved with pH 11.0 supernatant solution and precipitate, intact mucopeptide is not essential for hydrogenase binding. Release of hydrogenase during EDTA-lysozyme lysis was found to depend upon an apparent structural change which occurs in the membranes during extended storage at -20 C.
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PMID:Chemical constituents and hydrogenase binding in cell envelopes of Vibrio succinogenes. 497 63

We have obtained the electron paramagnetic resonance spectrum of Cu2+ bound in a tetragonal single crystal of hen egg-white lysozyme. A part of this spectrum has been shown to originate from Cu2+ ions bound at the site designated as B by Teichberg et al. [Teichberg, V.I., Sharon, N., Moult, J., Smilansky, A. & Yonath, A. (1974) J. Mol. Biol. 87, 357-368]. The values of the spin hamiltonian parameters that describe this part of the spectrum are reported. The implications of these values with respect to the chemical nature and configuration of ligands are discussed. The other features of the spectrum are also described.
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PMID:Electron paramagnetic resonance spectroscopy of Cu2+ in hen egg-white lysozyme. 625 70


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