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)

Lysozyme was adsorbed on spin cast and lathe cut soft contact lenses of poly-2-hydroxyethylmethacrylate (PHEMA) and on poly-HEMA-methacrylic acid (PHEMA/MAA). The in vitro adsorption process was followed by ATR-FTIR. Lysozyme adsorbs both, reversibly and irreversibly, on the surfaces. While the reversible bound lysozyme experiences only minor changes in its secondary structure, conformational changes occur for the irreversibly adsorbed protein. The type and extent of structural changes depend on the degree of protein coverage on the lens surface, as well as the chemical structure and surface morphology of the lenses. PHEMA/MAA lenses adsorbed thirty times more lysozyme than either of the PHEMA lenses. Fabrication processes appear to induce different adsorption behaviour, PHEMA lathe cut lenses adsorb twice the amount of protein compared with PHEMA spin cast lenses.
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PMID:Protein adsorption on hydrogels. II. Reversible and irreversible interactions between lysozyme and soft contact lens surfaces. 405 47

A technique was developed to accelerate lysozyme deposition on poly(HEMA) contact lenses and measure the amounts of the deposited lysozyme. This technique was for evaluation of bendazac lysine solution, a contact lens cleaning and wetting solution. Effect of temperature on lysozyme deposition on poly(HEMA) contact lenses was examined. Five temperatures ranging from 25 degrees C to 90 degrees C were chosen to examine the temperature effect. The amounts of lysozyme deposited on poly(HEMA) contact lenses at 25 C and 60 C were 0.27 microg/lens and 0.61 microg/lens, respectively. The amount increased sharply to 23 microg/lens at 70 degrees C with the maximum of 31 microg/lens at 90 degrees C. Kinetics of lysozyme deposition on poly(HEMA) contact lenses was examined at 80 degrees C. Lysozyme deposition increased sharply during the first 2 h and reached a plateau after 2 h. Effectiveness of various cleaning procedures was examined using bendazac lysine solution. When the contact lenses were washed without rubbing with fingers, the bendazac lysine reduced the amount of deposited lysozyme by more than 40% from 18.3 microg/lens to 10.6 microg/lens. The effect of bendazac lysine was most prominent when the contact lenses were shaken during storage in the presence of lysozyme in solution. If the contact lenses were cleaned by rubbing with fingers, the effect of bendazac lysine solution on the prevention of lysozyme deposition was negligible.
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PMID:Accelerated study on lysozyme deposition on poly(HEMA) contact lenses. 987 Jul 56

XPS and MALDI-MS were used to analyse initial adsorption events in the fouling of HEMA-based contact lenses. All of the lenses tested accumulated tear film deposits within 10 min of wear. XPS indicated the presence of mainly proteinaceous deposits, with indications of some contributions by mucins or lipids on some lenses and the nature of the deposit being influenced by the lens chemistry. MALDI-MS detected the presence of surface-adsorbed species with molecular weights < 15 kDa. While lysozyme could be identified by comparison of MALDI-MS signals with known protein mass and assignments are suggested for some other signals, several other species, with MWs less than that of lysozyme, could not be identified as no ocular proteins with corresponding MWs had been reported in previous biochemical tear film analyses. These species, and others, were also detected in MALDI-MS analysis of reflex tear film, suggesting that the adsorbed unidentified species were not simply products of surface-induced dissociation of adsorbing higher-MW proteins. This short-term wear study detected rapid interface conversion and demonstrated the utility and surface sensitivity of XPS and MALDI-MS in characterising contact lens deposits at the initial stages when sub-monolayer adsorbed amounts are present on lenses.
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PMID:XPS and surface-MALDI-MS characterisation of worn HEMA-based contact lenses. 1170 Aug 1

Different adsorbents have been reported in the literature for protein purification. The authors have developed a novel and new approach to obtain high protein adsorption capacity utilizing a 2-methacrylamidoalanine-containing membrane. Amino acid ligand 2-methacrylamidoalanine (MAAL) monomer was synthesized using methacryloyl chloride and alanine. Poly(2-hydroxyethylmethacrylate-co-2-methacrylamidoalanine) [p(HEMA-co-MAAL)] membranes were then prepared by UV-initiated photopolymerization of HEMA and MAAL in the presence of an initiator (azobisisobutyronitrile, AIBN). The synthesized MAAL monomer was characterized by NMR. p(HEMA-co-MAAL) membranes were characterized by swelling studies, porosimeter, SEM, FTIR, and elemental analysis. These membranes have macropores in the size range of 5-10 microm. Cu(II) ions (25.9 mmol/m2) were chelated on these membranes. p(HEMA-co-MAAL) membranes were used to study the adsorption of lysozyme from aqueous media containing different amounts of lysozyme (0.1-3.0 mg/l) and at different pH values (4.0-8.0). The non-specific adsorption of lysozyme on the pHEMA membranes was negligible (0.9 microg/cm2). Incorporation of MAAL increased the lysozyme adsorption significantly up to 2.96 mg/cm2. The lysozyme adsorption capacity of the Cu(II) incorporated membranes (9.98 mg/cm2) was greater than that of the p(HEMA-co-MAAL) membranes. More than 90% of the adsorbed lysozyme was desorbed in 1 h in the desorption medium containing 1.0 M NaCl and 0.025 M EDTA. The metal-chelate affinity membranes are suitable for repeated use for more than ten cycles without a noticeable loss of capacity.
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PMID:Poly(hydroxyethyl methacrylate-co-methacrylamidoalanine) membranes and their utilization as metal-chelate affinity adsorbents for lysozyme adsorption. 1218 59

Proteins, lipids and other biomolecules interact strongly with the acrylic-based biomaterials used for contact lenses. Although hydrogels are nominally resistant to protein fouling, many studies have reported considerable amounts of protein bound to poly(2-hydroxyethylmethacrylate) (PHEMA) lenses. This study examined the binding of a series of biomolecules (tear protein analogues, mucin and cholesterol) to poly(methylmethacrylate) (PMMA) and three HEMA-based hydrogels (PHEMA, HEMA plus methacrylic acid (P(HEMA-MAA)), HEMA plus methacrylic acid plus N-vinylpyrrolidone (P(HEMA-MAA-NVP))) by use of a quartz crystal microbalance with dissipation (QCM-D) monitoring. The QCM-D estimates changes in the mass and viscous constant for the adsorbed layer through measurements of frequency and dissipation. Protein interaction with each of the test materials caused a net increase in mass of the material indicating protein binding except for lysozyme interacting with P(HEMA-MAA). A net decrease in mass was observed for lysozyme interacting with P(HEMA-MAA) which may be ascribed to lysozyme collapsing the hydrogel by expelling water. A net mass decrease was observed for cholesterol interacting with each of the hydrogel materials, while a mass increase was observed on PMMA.
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PMID:The effect of charged groups on protein interactions with poly(HEMA) hydrogels. 1605 82

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.
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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.
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PMID:A new affinity-HPLC packing for protein separation: Cibacron blue attached uniform porous poly(HEMA-co-EDM) beads. 1623 Nov 38

Magnetic poly(2-hydroxyethyl methacrylate) mPHEMA beads carrying Cibacron Blue F3GA were prepared by suspension polymerization of HEMA in the presence of Fe3O4 nano-powder. Average size of spherical beads was 80-120 microm. The beads had a specific surface area of 56.0m(2)/g. The characteristic functional groups of dye-attached mPHEMA beads were analyzed by Fourier transform infrared spectrometer (FTIR) and Raman spectrometer. mPHEMA with a swelling ratio of 68% and carrying 28.5 micromol CibacronBlueF3GA/g were used for the purification of lysozyme. Adsorption studies were performed under different conditions in a magnetically stabilized fluidized bed (i.e., pH, protein concentration, flow-rate, temperature, and ionic strength). Lysozyme adsorption capacity of mPHEMA and mPHEMA/Cibacron Blue F3GA beads were 0.8 mg/g and 342 mg/g, respectively. It was observed that after 20 adsorption-desorption cycle, mPHEMA beads can be used without significant loss in lysozyme adsorption capacity. Purification of lysozyme from egg white was also investigated. Purification of lysozyme was monitored by determining the lysozyme activity using Micrococcus lysodeikticus as substrate. The purity of the desorbed lysozyme was about 87.4% with recovery about 79.6%. The specific activity of the desorbed lysozyme was high as 41.586 U/mg.
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PMID:Lysozyme purification with dye-affinity beads under magnetic field. 1741 99

Molecular imprinting is a method for making selective binding sites in synthetic polymers using a molecular template. The aim of this study is to prepare lysozyme-imprinted supermacroporous cryogels which can be used for the purification of lysozyme (Lyz) from egg white. N-Methacryloyl-(L)-histidinemethylester (MAH) was chosen as the metal-coordinating monomer. In the first step, Cu2+ was complexed with MAH and the lysozyme-imprinted poly(HEMA-MAH) [Lyz-MIP] cryogel were produced by free radical polymerization initiated by N,N,N',N'-tetramethylene diamine (TEMED) in an ice bath. After that, the template (i.e., lysozyme) was removed using 0.05 M phosphate buffer containing 1M NaCl (pH 8.0). The maximum lysozyme adsorption capacity was 22.9 mg/g polymer. The relative selectivity coefficients of Lyz-MIP cryogel for lysozyme/bovine serum albumin and lysozyme/cytochrome c were 4.6 and 3.2 times greater than non-imprinted poly(HEMA-MAH) (NIP) cryogel, respectively. Purification of lysozyme from egg white was also monitored by determining the lysozyme activity using Micrococcus lysodeikticus as substrate. The purity of the desorbed lysozyme was about 94% with recovery about 86%. The Lyz-MIP cryogel could be used many times without decreasing the adsorption capacity significantly.
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PMID:Protein recognition via ion-coordinated molecularly imprinted supermacroporous cryogels. 1839 14

During contact lens wear, tear film components such as lipids, mucins and proteins tend to deposit on and within the lens material and may cause discomfort, reduced vision and inflammatory reactions. The tear film protein that has attracted most interest when studying contact lens deposition is the small (14 kDa), positively charged protein lysozyme. Albumin, which is a much larger protein (66 kDa) with an overall net negative charge is also of interest, and shows very different adsorption patterns to lysozyme. The concentration of albumin in the tear film is relatively low compared to the concentration in blood serum, but this value increases markedly under various conditions, including when the eye is closed, during contact lens wear and in various dry eye states. Gaining an understanding of the manner in which albumin deposits on biomaterials is of importance for contact lens wear, as well as for other medical applications where HEMA-based materials are used for implants, artificial blood vessels or drug delivery devices. This review paper summarizes the impact of individual material compositions, water content, hydrophobicity and electrostatic attraction on the adsorption behavior of the protein albumin.
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PMID:Albumin adsorption to contact lens materials: a review. 1860 67


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