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 model system for the partitioning of peripheral membrane proteins into membranes by ligand binding has been examined experimentally. Both bovine serum albumin and lysozyme partition between water and 1-butanol by the addition of sodium p-toluene sulfonate at pH 2.4. The partitioning is characterized by high orders of reaction: 25 and 10, respectively. Theory indicates that these high orders of reaction need not result from cooperative ligand binding in either phase, but depend primarily upon the number N of protein sites at which the transfer-promoting ligant binds, and on the difference in free energy of formation delta F0s of the protein--ligand complexes in the two phases. From the reaction orders and the experimental values of N, 80 for albumin and 11 for lysozyme, delta F0s was calculated to be --0.5 kcal/mol (--2.1 kJ/mol) and --0.8 kcal/mol (--2.5 kJ/mol) per ligand bound, respectively. Experiments measuring the dependence on ligand concentration of the rate of protein electrophoresis across the water/butanol interface are described. These rates increase by more than two orders of magnitude as the ligand concentration approaches the critical value for partition and are inversely dependent on the number of ligant sites for the two proteins studied.
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PMID:Ligand-promoted transfer of proteins between phases: spontaneous and electrically helped. 27 41

The effects on the stringent control of ribosomal ribonculeic acid synthesis of the removal of cell wall, cold-shock treatment of cells, LiCl treatment of toluene-treated cells, and hypotonic treatment of spheroplasts were examined using Escherichia coli rel+ cells. Neither the removal of cell wall with penicillin or lysozyme nor the cold-shock treatment of the cells had an effect on the stringent control. The control mechanism, however, disappeared after the LiCl treatment of the toluene-treated cells, with the release of some protein component(s), possibly from the cytoplasmic membrane. The hypotonic and other treatments of spheroplasts, which disrupt the cytoplasmic membrane, also led to the abolishment of the control mechanism. These results suggested that the operation of the stringent control of ribosomal ribonucleic acid synthesis requires the cytoplasmic membrane, in which some proteins labile with LiCl treatment are embedded.
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PMID:Regulation of ribonucleic acid synthesis in spheroplasts, cold-shocked cells, and toluene-treated cells of Escherichia coli. 78 28

Initiation of new DNA synthesis was observed in B. subtilis cells upon gamma-ray irradiation followed by toluene treatment and incubation in the presence of the four deoxynucleotide triphosphates and Mg2+. This DNA synthesis took place in the absence of ATP and was refractory to 6-(p-hydroxyphenylazo)-uracil which is a specific inhibitor for the type III polymerase of Bacillus subtilis. This repair-type DNA synthesis was greatly reduced in mutant cells deficient in DNA polymerase I. Restoration of transforming activity of cellular DNA was found to occur in parellel with the above repair type DNA synthesis. A protein factor which enhances the priming activity of gamma-irradiated DNA for DNA polymerase I was detected in DNA-free extracts prepared from B. subtilis cells by means of lysis with a buffer containing lysozyme, Brij-58 and EDTA.
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PMID:Studies on DNA repair in Bacillus subtilis. I. A cellular factor acting on gamma-irradiated DNA and promoting its priming activity for DNA polymerase I. 80 54

In vitro deoxyribonucleic acid (DNA) synthesis systems based on an earlier system using pencillin have been developed which use osmotic lysis of lysozyme-formed spheroplasts of Escherichia coli cells embedded in an agarose matrix. An adenosine 5'-triphosphate (ATP)-dependent semiconservative mode, or replicative mode, of in vitro DNA synthesis is exhibited which is sensitivie to nalidixic acid. These systems require growth of the agar-embedded cells in a preincubation medium before spheroplast formation and osmotic lysis. Inhibitor studies suggest that one or more required macromolecular species are synthesized during this preincubation growth period. Osmotic shock fluid from E. coli contains macromolecular factors which preferentially stimulate the ATP- dependent semiconservative mode of in vitro DNA synthesis. In some cases, the ATP independent mode of synthesis is inhibited by shock fluid. Evidence is presented that the stimulating factors found in the osmotic shock fluid come from the E. coli periplasmic space. This stimulation is observed using either toluene-treated cells or lysed agar-embedded ethylene glycol-bis-(beta-aminoethyl ether) N,N'-tetraacetate-lysozyme spheroplasts, and is thus independent of the in vitro DNA synthesis system used. Shock fluid obtained from a given E. coli dna mutant does not stimulate in vitro DNA synthesis by that mutant. However, in some cases, shock fluid from one class of dna mutants does stimulate ATP dependent in vitro DNA synthesis by another class of dna mutants, in a thermosensitive reacaction. Gently prepared cell extracts also stimulate ATP-dependent in vitro DNA synthesis, whereas cell extracts prepared by more severe procedures inhibit this in vitro synthesis. Severl stimulating DNA replication factors may be present in the osmotic shock fluid, including products of E. coli dna genes.
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PMID:Stimulation of adenosine 5'-triphosphate-dependent in vitro deoxyribonucleic acid replication by factors from the periplasmic space of Escherichia coli. 109 20

A cross-sectional study was conducted to determine whether exposure to hydrocarbons in a shoe factory may produce renal effects that can be detected by determination of the urinary excretion of proteins and enzymes. The study population included 59 women who had been exposed to petroleum naphtha and toluene and 24 age-matched control women. The time-weighted average exposure to petroleum naphtha, toluene and ethylacetate was 1,619,81 and 160 mg/m3, respectively. The integrity of the renal structures or functions was assessed by measuring the urinary excretion of total protein, beta 2-microglobulin, retinol-binding protein, albumin, transferrin, lysozyme, lactate dehydrogenase and beta-N-acetylglucosaminidase (NAG). The only parameter that was significantly influenced by hydrocarbon exposure was the urinary activity of beta-N-acetylglucosaminidase. Although the health significance of this renal change, which was not accompanied by changes in the urinary excretion of low- or high-molecular-weight proteins, is unclear, the results of the present study are in agreement with our previous observations suggesting that long-term moderate exposure to solvents does not entail a significant risk for the development of nephrotoxicity.
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PMID:Urinary excretion of proteins and enzymes in workers exposed to hydrocarbons in a shoe factory. 176 14

During the period of 1983-1985, in two of apprentice schools of P. town the health disorders were investigated in the total of 82 apprentices 15-18 years old from the environment with elevated concentrations of formaldehyde and toluene. The study was contrasted with a control total of 42 apprentices. Cytogenetical examination has been performed, and selected immunological parameters in both blood serum and saliva have been assessed with red and white blood cells counts including differential formula of white blood cells. In addition, the atmospheric toxicity of formaldehyde and vapours of organic solvents (toluene, xylene, varnish naphtha) was measured. A single biological exposure test has been performed for the detection toluene. Statistically significant were differences in occurrence of cell chromosomal aberrations between the group of long term formaldehyde and toluene exposure (averagely 3.53% ABB) and controls (2.21% ABB) as obtained in 1983 and 1984, and so were differences between the long term-to-toluene exposed group (3.30% ABB) and the above mentioned control group as obtained in 1984. No similar results were stated between the long term-to-formaldehyde exposed (3.07% ABB) and control (2.55% ABB) groups in 1985. The main evidence consisted in finding the genotoxical/clastogenic effect of observed agents associated with mainly chromosomal abnormalities of chromatide type. It outflowed from the determination of selected serum proteins (Ig and acute phase proteins) and salivary lysozyme that the group under the combined influence of formaldehyde and toluene showed significantly lower IgG and higher alpha-1-antitrypsin (A1AT). The group at risk of toluene was characteristical in elevated concentrations of alpha-2-macroglobulin (A2M) and A1AT. Most pronounced changes in first year had been revealed through the evaluation of the influence of the duration at risk (significant decrease in IgA and prealbumin, and the increase in A2M and A1AT). The infectious disease as experienced 2 month prior the collection resulted in a significant decrease of IgM, A2M and A1AT in risky groups in individuals with infection in anamnesis. Salivary lysozyme concentration of apprentice environmentally exposed to formaldehyde in the noon showed the decrease, whereas its increase occurred in controls with the difference on 5% significancy level. Blood count assessements showed no significant differences between the investigated values as well as any were assessed between the incidence of health disorders of apprentices and their correspondance to the given group.
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PMID:[Environmental monitoring and biological monitoring of young people exposed to nonoccupational levels of formaldehyde, toluene and other hydrocarbons]. 181 45

Microcapsules (diameter range: 5 to 100 microns) prepared through interfacial cross-linking of proteins with terephthaloylchloride exhibited a cytotoxic effect on L 1210 cell cultures. IC50 was: 0.86 mg/ml +/- 0.24 for microcapsules prepared from human serum albumin (AT microcapsules) and 0.63 mg/ml +/- 0.05 for those obtained from egg white lysozyme (LT microcapsules). With K 562 cells IC50 were 0.42 +/- 0.11 mg/ml (AT microcapsules), 0.06 mg/ml (LT microcapsules). An increase in the cytotoxicity was observed when reducing the size of the microcapsules and when increasing the reaction pH or the terephthaloylchloride concentration, or the relative concentration of microcapsules vs cells. On the contrary, the cytotoxic effect decreased, when prolonging the cross-linking time. The activity was not affected when the microcapsules were washed with toluene or with an alkaline solute. The cytotoxic effect, which appears for relatively high doses, apparently involves a contact between the microcapsules and the cells and seems to be related with the degree of cross-linking of the constitutive protein.
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PMID:[The effect of cross-linked protein microcapsules on cell cultures]. 260 10

Forty-three workers exposed to low levels of toluene diisocyanate (TDI) during the process of producing polyurethane forms were examined immunologically for IgG, A, M, and E and serum enzyme activities such as serum angiotensin converting enzyme (SACE), serum lysozyme (SLZM) and glycylproline dipeptidyl aminopeptidase (GP-DAP). Air concentration of TDI was annually measured in various places of work during the past five years from 1979 to 1983. The results obtained in the present study were as follows. 1. The air concentration of TDI at all places of work was below the permissible concentration level of 0.02 ppm throughout the study period. 2. Subjective symptoms and abnormal findings on chest X-ray considered directly related to TDI exposure were not observed. 3. No remarkable abnormal findings in blood cell counts and in serum biochemical studies could be seen in any of the workers. 4. The serum IgG levels in workers directly exposed to TDI were significantly higher (p less than 0.05) than those in workers indirectly exposed to TDI and in non-exposed workers. 5. In the study of serum enzymatic activity, SLZM activity in workers exposed directly to TDI was significantly higher (p less than 0.01) than those in workers indirectly exposed to TDI and in non-exposed workers.
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PMID:[A study on the immunologic effects in workers exposed to low levels of toluene-diisocyanate (TDI)]. 304 Oct 74

The mass density of protein crystals can be measured in Ficoll gradients as a function of hydrostatic pressure. Carbon tetrachloride-toluene mixtures provide convenient density markers, and the compressibility of these standards is reported. Measurements on tetragonal crystals of hen egg-white lysozyme yielded densities at room temperature of 1.2367(+/- 0.0010) g cm-3 at 1 atm and 1.2586(+/- 0.0017) g cm-3 at 1000 atm (1 atm = 101,325 Pa). When combined with the unit cell dimensions at these two pressures these values lead to an estimated compression (fractional change in volume) of the crystal solvent at 1000 atm of 0.0369(+/- 0.0054). This value is comparable to that of a 0.7 M solution of NaCl. From an approximate estimate of the Donnan effect for the crystal in the 1.4 M-NaCl mother liquor, the crystal solvent contains 0.8 M-Na+ and 2.5 M-Cl-. It is concluded that the compressibility of solvent in lysozyme crystals is, within experimental error, the same as bulk solvent and does not exhibit the dramatically altered compressibility expected of an ice or glass-like solid. The crystallographically observable water sites, 151 at 1 atm and 163 at 1000 atm, showed a tendency to increase the number of hydrogen bonds made to other water sites at the expense of hydrogen bonds made to protein. The explanation for this phenomenon is presently unknown. Water sites that occur in both structures tend to have comparable temperature factors and show some tendency to follow the pressure-induced changes in protein atom positions. The compression expected for the water molecules themselves is too small to be observable at the resolution of the X-ray data collected in this study.
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PMID:Effect of hydrostatic pressure on the solvent in crystals of hen egg-white lysozyme. 337 35

Transfer ribonucleic acid (tRNA) nucleotidyltransferase was studied after making cells permeable to macromolecules by treatment with toluene. The conditions of toluene treatment necessary for obtaining maximal activity were defined. Toluene treatment was most efficient when carried out for 5 min at 37 C at pH 9.0 on log-phase cells. No activity could be detected if cells were treated at 0 C, or in the presence of MgCl(2), or if the cells were in the stationary phase of growth. However, inclusion of lysozyme and ethylenediaminetetraacetic acid during the toluene treatment did render stationary phase cells permeable. The properties of tRNA nucleotidyltransferase from toluene-treated cells were essentially identical to those of purified enzyme with regard to pH optimum, specificity for nucleoside triphosphates and tRNA, and apparent K(m) values for substrates. In addition to tRNA nucleotidyltransferase, a variety of other enzymes which incorporate adenosine 5'-triphosphate into acid-precipitable material could also be detected in toluene-treated cells. Centrifugation of cells treated with toluene revealed that tRNA nucleotidyltransferase leaked out of cells, whereas other activities remained associated with the cell pellets. Chromatography of the material extracted from toluene-treated cells on Sephadex G-100 indicated that toluene treatment selectively extracts lower molecular weight proteins. The usefulness of such a procedure as an initial step in purification of such enzymes, and its application to tRNA nucleotidyltransferase, is discussed.
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PMID:Preparation of cells permeable to macromolecules by treatment with toluene: studies of transfer ribonucleic acid nucleotidyltransferase. 459 54


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