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

---

Query: EC:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

Deposits on soft contact lenses of high water content were investigated morphologically and chemically and compared with those on conventional soft contact lenses of poly (2-hydroxyethyl methacrylate). The material of the lenses examined in this investigation was the crosslinked copolymer of methyl methacrylate and N-vinylpyrrolidone with a water content higher than 70%. Morphologically, the deposits on the lenses with high water content were found to have no characteristics distinguishable from those on conventional lenses. By the electron microscopic observation of the cross section of a lens that had become opaque, it was confirmed that the deposit was on the lens surface and that no deposit was within the lens. Some spots on the lenses were recognized as colonies of microorganisms, but the majority of the spots had no involvement by microorganisms. Surface analysis with Fourier transform infrared spectrometer (FT-IR) confirmed that the main component of the filmy deposit was protein. Protein was detected in most of the deposits. The amino acid compositions of the proteins were found to be close to that of lysozyme. From the elemental analysis of several spots, silicon, aluminum, iron, and some other elements were detected. The structural analysis of some spots by a laser Raman microprobe (MOLE) revealed the existence of lipids. In several cases, the deposits were found to have grown around a defect of the lens surface. A mechanism for the formation of deposits is suggested.
...
PMID:Analysis of deposits on high water content contact lenses. 684 67

An in vitro quantitative study of the adhesion of a Staphylococcus aureus strain to two types of disposable contact lenses has been carried out. The first type was an ionic/high-water-content (I-HWC) lens (42% Etafilcon A, 58% water) and the second was a non-ionic/low-water-content (Nl-LWC) lens (61.4% poly(2-hydroxyethyl methacrylate), 38.6% water). Adhesion to the two lens types was evaluated both in basic conditions and after treatment with lysozyme. The results showed that I-HWC lenses are more prone to Staphylococcus aureus adhesion than NI-LWC lenses, both untreated (+15.4%) and treated with lysozyme (+20.5%). Lysozyme increased bacterial adhesion by 30.5% on the lenses with lower water content, and by 36.3% on those with higher water content.
...
PMID:Disposable contact lenses and bacterial adhesion. In vitro comparison between ionic/high-water-content and non-ionic/low-water-content lenses. 757 71

Reduced and acetylated lysozymes are basic proteins. When their amino groups were variously acetylated and then renatured by sulfhydryl-disulfide (SH-SS) interchange reaction at pH 8.0, the final folding yield decreased as the number of positive charges decreased. The final folding yield of native and Ac1 lysozyme, with one positive charge eliminated, was less sensitive to increasing protein concentration than that of Ac2 lysozyme, where two positive charges had been eliminated. The final folding yield of reduced Ac2 lysozyme increased in the presence of 1 M urea, which reduced the aggregation of unfolded lysozyme. Thus, the aggregation of unfolded lysozymes, which leads to a decrease in the final folding yield, was found to be heavily dependent on their net charges. Moreover, the final folding yield of reduced lysozyme was shown to be increased by use of cystamine as an oxidizing reagent in comparison with 2-hydroxyethyl disulfide or dithiodiglycolic acid. This may support the idea that the final folding yield is influenced by electrostatic interaction between unfolded lysozymes in the early stage of renaturation. In contrast, the concentration dependency of the final folding yield of Ac1 lysozyme was different from those of carboxymethylated His15 and Asp106 lysozymes whose positive net charges were similar to that of Ac1 lysozyme. On the basis of the observations, it is suggested that the formation of the aggregates in the renaturation process might also be affected by the structure of the unfolded state of lysozyme in solution.
...
PMID:The role of net charge on the renaturation of reduced lysozyme by the sulfhydryl-disulfide interchange reaction. 785 40

A series of hydrogels with large pores was synthesized by the precipitation polymerization of 2-hydroxyethyl methacrylate (HEMA) with crosslinking agent in aqueous solution. Such gels are potentially useful for the controlled release of large-molecular-weight species such as proteins. In this study, the release behavior of lysozyme and alpha-amylase from hydrogels formed from HEMA or HEMA with a comonomer was studied. It was found that the polymer composition affected the total amount of lysozyme released and its activity. Effects were smaller with alpha-amylase. Charged gels, containing a phosphate moiety, released larger amounts of lysozyme at a reduced rate as a result of charge-charge interactions.
...
PMID:Controlled release of proteins from 2-hydroxyethyl methacrylate copolymer gels. 846 34

The use of zymograms in which the bacterial cell wall heteropolymer peptidoglycan is incorporated into the resolving gel of SDS-PAGE has led to the identification of various SDS stable peptidoglycan hydrolases (autolysins). To examine the specificity of autolysins with respect to O-acetylated peptidoglycan, a discontinuous SDS-PAGE system has been developed that operates under neutral conditions. [Bis(2-hydroxyethyl)imino]tris(hydroxymethyl)methane (Bis-Tris) buffers are employed with pH 6.8 and 6.3 for the separating and stacking gels, respectively, while the anode buffer N-2-acetamido-2-hydroxyethanesulfonic acid (Aces)-HCl and the Bis-Tris cathode buffer both had a pH of 6.8. These conditions resulted in a relative trailing ion mobility of 0.349 and 0.137 in the resolving and staking gel, respectively, under room temperature conditions. Peptides and proteins were resolved in the 3-100 kDa range with a 10% acrylamide resolving gel. Comparison of zymograms that incorporated unacetylated or chemically O-acetylated peptidoglycan revealed the specificity of hen egg-white lysozyme for the unacetylated material. A preliminary analysis of the autolysins produced by the urinary tract pathogen Proteus mirabilis indicated that some enzymes were specific for either O-acetylated or non-O-acetylated peptidoglycan while others displayed no clear preference toward either of the two substrates.
...
PMID:Differentiation of bacterial autolysins by zymogram analysis. 1126 68

Many commercial soft contact lenses are based on poly-2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) hydrogels. The adsorption of proteins, albumin and lysozyme, on such contact lens surfaces may cause problems in their applications. In this work the adsorption of proteins, albumin and lysozyme, on hydrogel surfaces, AA and HEMA, was investigated as a function of concentration of protein. Also the effects of pH and ionic strength of protein solution on the adsorption of protein were examined. The obtained results indicated that the degree of adsorption of protein increased with the concentration of protein, and the adsorption of albumin on HEMA surface at the studied pHs (6.2-8.6) was higher than AA surface, whereas the adsorption of lysozyme on AA surface at the same pHs was higher than HEMA. The change in ionic strength of protein solution affected the proteins adsorption on both AA and HEMA surfaces. Also, the amount of sodium ions deposited on the AA surface was much higher than HEMA surface. This effect can be related to the negative surface charge of AA and its higher tendency for adsorption of sodium ions compared to the HEMA surface.
...
PMID:Experimental study of albumin and lysozyme adsorption onto acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) surfaces. 1475 71

The wettability of poly[2-hydroxyethyl methacrylate-co-methacrylic acid] (pHEMA-MAA) soft contact lenses was investigated in the absence and presence of block copolymer surfactants and lysozyme using the sessile drop method. The advancing dynamic contact angles (Thetaw/a) values are reported for water as a function of sequential wetting and drying cycles. The Thetaw/a values for the pHEMA-MAA in the absence of surfactant and lysozyme increased from approximately 20 degrees to 100 degrees as the number of cycles increased from two to ten, and they were independent of the pHEMA-MAA bulk water content. The change from the highly hydrophilic to hydrophobic pHEMA-MAA surface could not be reversed using the sequential wetting and drying cycles even under repeated exposures to saline solution. The effect of block copolymer surfactants with different molecular weights (MW) and hydrophilic-lipophilic balance (HLB) values on the pHEMA-MAA wettability were also studied. Low Theta(w/a) values were observed for pHEMA-MAA hydrogels that were treated with T1304 (MW 10500, HLB 14) and T904 (MW 6700, HLB 15). The surface tension data indicated that these surfactants were incompletely desorbed from the pHEMA-MAA and that the rate of desorption was slow in the timescale of the cycling experiments. Comparatively, poor wettability was observed for pHEMA-MAA surfaces presoaked in T304 (MW 1650, HLB 16) and T1107 (MW 15000, HLB 24) as Thetaw/a values greater than 90 degrees were measured for these surfactants. The surface tension data indicated that the rate of desorption of T304 and T1107 from the pHEMA-MAA was rapid and that they had a low affinity to the pHEMA-MAA. High contact angles were observed for the pHEMA-MAA hydrogels treated with lysozyme and also for the T1107 presoaked pHEMA-MAA that was also treated with lysozyme. Zero wetting angles throughout the sequential cycling were observed for the T1304 pre-treated pHEMA-MAA that had been treated with lysozyme. These results suggested that the adsorbed lysozyme on the pHEMA-MAA hydrogel had no significant influence on its wetting properties when the hydrogel was pre-treated with T1304.
...
PMID:Dynamic wettability properties of a soft contact lens hydrogel. 1562 Aug 33

Lysozyme interaction with an acrylic-based hydrogel, poly(2-hydroxyethyl methacrylate) co-methacrylic acid (P(HEMA-MAA)), was investigated using a combination of quartz crystal microbalance with dissipation (QCM-D), surface plasmon resonance (SPR) and dual polarisation interferometry (DPI). This combination of techniques demonstrated that lysozyme initially absorbed into the hydrogel matrix and displaced water from the hydrogel while subsequent lysozyme additions were adsorbed onto the surface of the hydrogel material. QCM-D, being sensitive to bound water, showed an overall decrease in mass and stiffening of the layer after lysozyme addition. SPR, a water insensitive technique, showed a net mass increase after addition of lysozyme and buffer rinses. DPI showed that the first exposure of lysozyme to P(HEMA-MAA) was consistent with lysozyme absorption while subsequent lysozyme exposures were consistent with lysozyme adsorption.
...
PMID:Lysozyme interaction with poly(HEMA)-based hydrogel. 1618 13

In this study, a new affinity high-performance liquid chromatography (HPLC) stationary phase suitable for protein separation was synthesized. In the first stage of the synthesis, uniform porous poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate), poly(HEMA-co-EDM), beads 6.2 mum in size were obtained. Homogeneous distribution of hydroxyl groups in the bead interior was confirmed by confocal laser scanning microscopy. The plain poly(HEMA-co-EDM) particles gave very low non-specific protein adsorption with albumin. The selected dye ligand Cibacron blue F3G-A (CB F3G-A) was covalently linked onto the beads via hydroxyl groups. In the batch experiments, albumin adsorption up to 60 mg BSA/g particles was obtained with the CB F3G-A carrying poly(HEMA-co-EDM) beads. The affinity-HPLC of selected proteins (albumin and lysozyme) was investigated in a 25 mm x 4.0-mm inner diameter column packed with CB F3G-A carrying beads and both proteins were successfully resolved. By a single injection, 200 mug of protein was loaded and quantitatively eluted from the column. The protein recovery increased with increasing flow rate and salt concentration of the elution buffer and decreased with the increasing protein feed concentration. During the albumin elution, theoretical plate numbers up to 30,000 plates/m were achieved by increasing the salt concentration.
...
PMID:A new affinity-HPLC packing for protein separation: Cibacron blue attached uniform porous poly(HEMA-co-EDM) beads. 1623 Nov 38


1 2 3 4 5 Next >>

---