Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A nonionic, high-water-content, high-strength hydrogel based on N-vinyl pyrrolidinone (NVP) and a novel hydrophilic-bulky monomer, 4-t-butyl-2-hydroxycyclohexylmethacrylate (TBCM), was developed. The TBCM was prepared in three relatively simple, high-yield steps. The copolymerization of NVP with varying concentrations of TBCM resulted in transparent hydrogel films possessing a wide range in mechanical and physical properties. A copolymer composition of 91.7 parts NVP, 8.0 parts TBCM, and 0.3 parts ethylene glycol dimethacrylate (EGDMA) gave a transparent, flexible film possessing a water content of 86%, a modulus of 130 g/mm2, and a tear strength of 3.4 g/mm. In contrast, a copolymer composition of 49.7 parts NVP, 50 parts TBCM, and 0.3 parts EGDMA gave a transparent, hard hydrogel film possessing a water content of 26% and a modulus of 86,000 g/mm2. All of the high-water copolymer compositions developed resulted in lysozyme uptake typical of nonionic high-water-content hydrogels and oxygen permeability levels greater than 50 (cm3-O2(STP).cm)/(s.cm2.mm Hg) x 10(-11).
 ...
PMID:High-strength hydrogels based on N-vinyl pyrrolidinone and 4-t-butyl-2-hydroxycyclohexylmethacrylate. 157 35

Of the interactions that govern protein adsorption on polymer surfaces, solvation interactions (repulsive hydration and attractive hydrophobic interactions) are thought to be among the most important. The solvation interactions in protein adsorption, however, have not been dealt with in theoretical calculation of the adsorption energy owing to the difficulties in modelling such interactions. We have evaluated the solvation interaction energies using the fragment constant method of calculating the partition coefficients of amino acids. The fundamental assumption of this approach is that the partition coefficients of amino acids between water and organic solvent phases are related to the free energies of transfer from bulk water to the polymer surface. The X-ray crystallographic protein structures of lysozyme, trypsin, immunoglobulin Fab, and hemoglobin from the Brookhaven Protein Data Bank were used. The model polymer surfaces were polystyrene, polypropylene, polyethylene, poly(hydroxyethyl methacrylate) [poly(HEMA)], and poly(vinyl alcohol). All possible adsorption orientations of the proteins were simulated to study the effect of protein orientation on the solvation interactions. Protein adsorption on either hydrophobic or hydrophilic polymer surfaces was examined by considering the sum of solvation and other interaction energies. The results showed that the contribution of the solvation interaction to the total protein adsorption energy was significant. The average solvation interaction energy ranged from -259.1 to -74.1 kJ/mol for the four proteins on the hydrophobic polymer surfaces, such as polystyrene, polypropylene, and polyethylene. On the other hand, the average solvation interaction energies on hydrophilic surfaces such as poly(HEMA) and poly(vinyl alcohol) were larger than zero. This indicates that repulsive hydration interactions are in effect for protein adsorption on hydrophilic polymer surfaces. The total interaction energies of the proteins with hydrophobic surfaces were always lower than those with more hydrophilic surfaces. This trend is in agreement with the experimental observations in the literature. This study suggests that consideration of the solvation interaction energies is necessary for accurate calculation of the protein adsorption energies.
 ...
PMID:Calculation of solvation interaction energies for protein adsorption on polymer surfaces. 176 35

In an attempt to understand the mechanisms of protein adsorption at the solid-liquid interface, we have calculated the interaction potential energy between the protein and the polymer surface by a computer simulation approach. The adsorption of four proteins--lysozyme, trypsin, immunoglobulin Fab, and hemoglobin--on five polymer surfaces was examined. The model polymers used for the calculation were polystyrene, polyethylene, polypropylene, poly(hydroxyethyl methacrylate), and poly(vinyl alcohol). All possible orientations of the protein on the polymer surfaces were simulated and the corresponding interaction energies for the initial contact stage of protein adsorption were calculated. In the calculation of interaction energies, the hydrophobic interaction was not treated explicitly owing to the difficulty in the theoretical treatment. The results showed that the interaction energy was dependent on the orientation of the protein on the polymer surfaces. The energy varied from -850 to +600 kJ/mol with an average of about -155 kJ/mol. The interaction energy was also dependent on the type of polymer. The average interaction energies of the four proteins with poly(vinyl alcohol) were always lower than those with the other polymers. The interaction energy was not dependent on the protein size. It was found that the dispersion attraction played the major role in protein adsorption on neutral polymer surfaces.
 ...
PMID:Protein adsorption on polymer surfaces: calculation of adsorption energies. 177 35

The immunobiochemical studies were conducted in a group of 98 production workers engaged in polyvinyl chloride manufacture from ethylene (group A workers) and in a group of 59 vinyl chloride workers from a chemical plant employing classic production technology from acetylene (group B workers). Both groups of workers were matched by age (group A workers: 37.7 +/- 8.66 years; group B workers: 34.9 +/- 11.2 years) and average exposure length (group A workers: 8.6 +/- 3.0 years; group B workers: 10.7 +/- 8.4 years). All workers were examined for the serum concentrations of immunoglobulins IgG, IgA and IgM and acute reactants lysozyme (LYS), transferrin (TRF), ceruloplasmin (CPL), alpha-l-antitrypsin (AlAT), alpha-2-macroglobulin (A2M) and orosomucoid (ORO). The statistical analysis included calculations of means, standard deviations and 95% confidence intervals. Differences in means were evaluated by t-test, differences in the distribution pattern of values by F-test. Abnormality of values was assessed by comparisons to normal values valid in Czechoslovakia. Group A worked in conditions meeting the MAC 10 mg VC.m-3 comparing with group B workers had elevated levels of IgG (P less than 0.005), IgA and IgM (P less than 0.001 both). Group B workers differed from group A workers by exhibiting significantly elevated levels of AlAT, and CPL. (P less than 0.001). The differences in the frequency of abnormal values between group A and group B worked in substantially less favourable hygienic conditions were significant for immunoglobulins elevated in group A and for ORO (P less than 0.01) and CPL (P less than 0.001) elevated in group B. The possible relationship of these immunobiochemical findings with the degree of vinyl chloride exposure are critically analyzed.
 ...
PMID:Immunobiochemical profiles of workers differing in the degree of occupational exposure to vinyl chloride. 246 35

A series of polymers and copolymers of 2-hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA) were synthesized in order to find surfaces that would adsorb minimal amounts of protein. The adsorption of albumin, lysozyme and immunoglobulin G from a three-way mixture of these proteins in isotonic buffered saline to the polymers was measured using 125I-labeled proteins. Apparently high protein uptake on copolymers rich in HEMA was found to be due to sorption of unbound 125I by the polymers. 125I sorption by the polymers was minimized by dialysis of the protein solution to remove unbound 125I iodide and inclusion of 0.01 M sodium iodide to block uptake of residual 125I iodide. Using these improved protocols, minimal total protein uptake was observed on copolymers containing 50% or more HEMA. The majority of adsorbed protein on all p(MMA-HEMA) polymers was albumin. Total protein uptake was greatest on pMMA. Commercial contact lenses composed of copolymers of HEMA and N-vinyl pyrrolidone (NVP) or acrylamide (AAm) adsorbed small amounts of all proteins whereas copolymers of methacrylic acid (MAAc) and HEMA adsorbed much larger quantities of lysozyme. These results indicate that protein uptake by contact lens materials varies greatly with polymer composition. Artifactually high "adsorption" can occur if precautions are not taken to prevent uptake of unbound 125I.
 ...
PMID:Adsorption of proteins from artificial tear solutions to contact lens materials. 334 93

A method that makes use of polyacrylamide gel electrophoresis was developed for the analysis of intramolecular disulfide bonds in proteins. Proteins with different numbers of cleaved disulfide bonds are alkylated with iodoacetic acid or iodoacetamide as the first step. The disulfide bonds remaining were reduced by excess dithiothreitol, and the newly generated free sulfhydryl groups were alkylated with the reagent not yet used (iodoacetamide, iodoacetic acid, or vinyl-pyridine) as the second step. This treatment made it possible for lysozyme (Mr, 14,000; 4 disulfides), the N-terminal half-molecule of conalbumin (Mr, 36,000; 6 disulfides), the C-terminal half-molecule of conalbumin (Mr, 40,000; 9 disulfides), and whole conalbumin (Mr, 78,000; 15 disulfides) to be separated by acid-urea polyacrylamide gel electrophoresis into distinct bands depending on the number of disulfide bonds cleaved. The method allowed us to determine the total number of disulfide bonds in native proteins and to assess the cleaved levels of disulfide bonds in partially reduced proteins. Two-step alkylation used in combination with radioautography was especially useful for the analysis of disulfide bonds in proteins synthesized in complex biological systems.
 ...
PMID:Analyses of intramolecular disulfide bonds in proteins by polyacrylamide gel electrophoresis following two-step alkylation. 336 12

Plasma levels of granulocyte elastase in complex with alpha 1-proteinase inhibitor during hemodialysis were investigated in 15 patients (37.4 +/- 3.2 years) undergoing maintenance hemodialysis (47.0 +/- 12.9 months) with dialyzers made from cellulose hydrate, cuprophan, polymethylmethacrylate, ethylene-vinyl alcohol copolymer, and polyacrylonitrile. Cellulose hydrate membrane caused a maximal increase of the plasma levels of granulocyte elastase in complex with alpha 1-proteinase inhibitor (E-alpha 1PI: 1,659.0 +/- 256.8 ng/ml). Patients dialyzed with polyacrylonitrile dialyzers failed to exhibit comparable plasma levels of granulocyte elastase (E-alpha 1PI: 237.8 +/- 22.9 ng/ml). During hemodialysis plasma E-alpha 1PI values rose to a peak 643.0 +/- 174.7 ng/ml in patients on polymethylmethacrylate dialyzers, to 557.5 +/- 120.0 ng/ml on cuprophan dialyzers, but to only 381.9 +/- 54.0 ng/ml on ethylene-vinyl alcohol copolymer dialyzers. Plasma lysozyme levels decreased significantly in the presence of polyacrylonitrile and polymethylmethacrylate membranes. We conclude that the degree of PMNs stimulation depends on the nature of the dialyzer membrane material. The following membranes induce a reaction of increasing intensity: polyacrylonitrile, ethylene-vinyl alcohol copolymer, cuprophan, polymethylmethacrylate, and cellulose hydrate.
 ...
PMID:Plasma levels of granulocyte elastase during hemodialysis: effects of different dialyzer membranes. 387 6

Following the administration of Di Luzio particulate glucan, Corynebacterium parvum, pyran (maleic anhydride vinyl ether 6), and lipopolysaccharide (Shigella) to inbred C57BL/6J mice, dose, route, and time-dependent studies were undertaken on antitumor activity and serum lysozyme levels to explore the possible relevance of serum lysozyme as a useful index of antitumor activity. Antitumor activity was assessed by measurement of the extent of loss of iv injected 125I-labeled 5-iodo-2'-deoxyuridine-labeled B16 tumor cells. Increases in serum lysozyme levels were dose-, route-, and time-dependent and varied greatly from one agent to another. The peak levels of antitumor activity were similar for all agents but were also critically dose- and time-dependent. Correlations of serum lysozyme levels and antitumor activity were inexact. The doses for peak lysozyme level increases were higher than those for peak antitumor activity. Antitumor activity peaked earlier and lasted longer than serum lysozyme level increases.
 ...
PMID:Dose, route, and time dependence of serum lysozyme and antitumor activity following administration of glucan, Corynebacterium parvum, pyran, or lipopolysaccharide to mice. 694 57

A series of indicators, including serum lysozyme activity, G-banding chromosome aberration (G-banding CA) analysis, sister chromatid exchanges (SCEs), chromosome aberration (CA), T-lymphocyte transformation rate (TcTR), gamma-GT, GPT and AKP, were employed in the present survey among occupationally vinyl chloride (VC) exposed workers and inhabitants living in VC polluted area in a polyvinyl chloride (PVC) factory. The results showed that the serum lysozyme (S-LZM) activities in Group 3 (adult inhabitants exposed to 0.20 mg/m3 VC for at least 8 years), Group 2 (workers exposed to 4.1 mg/m3 for at least 7 years occupationally), Group 1 (workers exposed to 25.7 mg/m3 for at least 2 years) were significantly higher than control. G-banding CA analysis showed that the total chromosome breakage rates in both Groups 1 and 2 were higher, but no difference existed between Group 3 and control. Only Group 1 was observed having higher SCEs, CA level and lower TcTR than control. AKP levels in Groups 1 and 2 were higher than control, but no gamm-GT and GPT differences were found among groups. The study also suggests that G-banding CA analysis is more sensitive than CA and SCEs.
 ...
PMID:The study of health effects of vinyl chloride air pollution on population. 794 9

We describe the application of a novel technique for the continuous counter-current chromatography of proteins. The unit operation has shown potential in extracting targeted species from unclarified feedstocks, delivering clarified streams of purified product. The adsorbent used in this equipment consists of a perfluorocarbon matrix, coated with poly(vinyl alcohol), and derivatized with the triazine dye Procion Red HE-7B. Purification of lysozyme from egg-whites and enriched bovine milk could be carried out continuously. The former was extracted in 90.5% yield at a rate of 7400 U/min, achieving a purification factor of 19.4. Lysozyme from the enriched milk sample was extracted continuously at a rate of 41000 U/min, in 66.0% yield. The continuous products streams in both cases were fully clarified, thus enabling their direct application to a final polishing step, if desired.
 ...
PMID:Direct purification of lysozyme using continuous counter-current expanded bed adsorption. 902 59


1 2 3 4 5 6 7 8 9 10 Next >>