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)

Classical model system: Poly-L-glutamic acid (Poly-Glu) was investigated in a disordered coil state (at pH-7.0) and in helix state (at pH 2.0) by Rayleigh scattering of Moessbauer radiation technique. Consider that the coil state of poly-Glu models unfolded (random coil) state and alpha-helix state models the fluctuating secondary structure (during consequent folding of protein) comparative analysis of dynamical properties of poly-Glu in different states with dynamical properties of different proteins in native state (alpha-helical myoglobin and HSA, partially beta-sheet lysozyme) and in intermediate (molten globule) state (alpha-lactalbumin) was performed. This comparison bring some surprising results: native alpha-helical proteins behave itself close to random coil, native partially beta-sheet protein behaves close to fluctuating secondary structure (alpha-helix) and the dynamic behaviour of molten globule state (partially beta-sheet alpha-lactalbumin) is not different from those behaviour of lysozyme and much more rigid than native alpha-helical proteins. As a result one cannot exclude the possibility that folding process and dynamical properties at different steps of the folding are very different for alpha-helical and beta-sheet proteins.
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PMID:[Comparison of dynamic properties of various globular proteins and polyglutamic acid in alpha-helical and coil states. Rayleigh scattering of Mossbauer radiation data]. 918

Poly(styrene-divinylbenzene) (PS-DVB) chromatography matrices, CG1000sd 20-50 microns (TosoHaas), PLRP4000s 15-25 microns, PLRP4000s 50-70 microns (Polymer Laboratories) have been modified by the adsorption and crosslinking of poly(vinyl alcohol) (PVA) to create a matrix suitable for the attachment of dye ligands. The adsorption capacities of lysozyme and HSA on these Procion Yellow HE-3G dyed PVA modified PS-DVB matrices were measured at various flow-rates and the capacities were compared with a Procion Yellow HE-3G dyed OH-activated POROS 20, 20-micron matrix (PerSeptive Biosystems). The adsorption of small proteins was not hindered by the smaller pores of the CG1000sd beads, but as protein size increased, and at high flow-rates, a high mass transfer rate became more dependent on large pore size and small particle diameter.
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PMID:Modification of polystyrenic matrices for the purification of proteins. III. Effects of poly(vinyl alcohol) modification on the characteristics of protein adsorption on conventional and perfusion polystyrenic matrices. 928 79

Poly(N-isopropylacrylamide), or PNIPAAm, is considered a "smart" polymer because it sharply precipitates when heated above a critical temperature, about 32 degrees C in water, and redissolves when cooled. Conjugates made of PNIPAAm and IgG antibodies also exhibit the same critical temperature behavior. Interestingly, antigens that are complexed with these conjugates can also be phase-separated along with the conjugates. In this work, we conjugated PNIPAAm for the first time to the immunoglobulin Fv fragment, the smallest fragment of an antibody that still retains the antigenic affinity of the whole antibody. For our studies, we used an Fv fragment that strongly binds hen egg white lysozyme (HEL). The purified Fv fragment-polymer conjugate precipitated at the same temperature as did the pure polymer. After addition of the conjugate to a mixture containing HEL and after thermal separation of the conjugate at 37 degrees C, the amount of HEL in solution was reduced by as much as 80%. We were able to demonstrate the reversibility of the separation through three cycles of precipitation and dissolution. It was also possible to recover free HEL by thermal separation of the conjugate in the presence of an eluant, 50 mM diethylamine. The conjugate can then be recycled for second use. In conclusion, immunoseparations can be performed using smart polymer conjugates made with just the variable domains of an antibody. Unlike whole antibodies, fragments of antibodies can be produced in Escherichia coli, allowing easier genetic engineering of the antibody and tailoring of the conjugate.
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PMID:Affinity separation using an Fv antibody fragment-"smart" polymer conjugate. 1211 15

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

To obtain the controlled release of proteins from macro-porous polymeric scaffolds, a novel emulsion-coating method has been developed. In this process, a water-in-oil emulsion, from an aqueous protein solution and a polymer solution, is forced through a prefabricated scaffold by applying a vacuum. After solvent evaporation, a polymer film, containing the protein, is then deposited on the porous scaffold surface. This paper reports the effect of processing parameters on the emulsion coating characteristics, scaffold structure, and protein release and stability. Poly(ether-ester) multiblock copolymers were chosen as the polymer matrix for both scaffolds and coating. Macro-porous scaffolds, with a porosity of 77 vol% and pores of approximately 500 microm were prepared by compression moulding/salt leaching. A micro-porous, homogeneous protein-loaded coating could be obtained on the scaffold surface. Due to the coating, the scaffold porosity was decreased, whereas the pore interconnection was increased. A model protein (lysozyme) could effectively be released in a controlled fashion from the scaffolds. Complete lysozyme release could be achieved within 3 days up to more than 2 months by adjusting the coated emulsion parameters. In addition, the coating process did not reduce the enzymatic activity. This new method appears to be promising for tissue engineering applications.
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PMID:A novel method to obtain protein release from porous polymer scaffolds: emulsion coating. 1261 23

Poly(N-isopropylacrylamide) (PNIPA) microgels may offer several advantages over PNIPA-modified surfaces when used as sorbents in temperature-sensitive chromatography. Yet, a full exploitation of these advantages requires a better understanding of the mechanisms controlling the separation process. As a model system, we have studied the binding of three proteins (bovine serum albumin (BSA), ovalbumin, and lysozyme) to PNIPA microgels. Binding experiments were conducted both below (25 degrees C) and above (37 degrees C) the volume phase transition temperature of the gel, T(c). The analysis of the binding isotherms has shown that although an average gel particle contained a larger amount of protein below the phase transition temperature, the concentration of the protein within the particle was higher above this temperature. These findings were attributed to changes in the binding loci due to temperature swings around T(c): whereas a sorption mechanism is dominant below this temperature, surface-adsorption was more important above it. A comparison between the three studied proteins has shown that below T(c) the binding increases with a decrease in the molecular weight. On the other hand, no significant difference in the bound protein amounts was observed above the phase transition temperature. Our results imply that, despite the increase in the gel's hydrophobicity above the phase transition temperature, the resolution in bioseparations based on PNIPA gels is not necessarily better above T(c).
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PMID:Mechanisms controlling the temperature-dependent binding of proteins to poly(N-isopropylacrylamide) microgels. 1465 48

This work examines physico-chemical properties influencing protein adsorption to anionic PLG microparticles and demonstrates the ability to bind and release vaccine antigens over a range of loads, pH values, and ionic strengths. Poly(lactide-co-glycolide) microparticles were synthesized by a w/o/w emulsification method in the presence of the anionic surfactant DSS (dioctyl sodium sulfosuccinate). Ovalbumin (OVA), carbonic anhydrase (CAN), lysozyme (LYZ), lactic acid dehydrogenase, bovine serum albumin (BSA), an HIV envelope glyocoprotein, and a Neisseria meningitidis B protein were adsorbed to the PLG microparticles, with binding efficiency, initial release and zeta potentials measured. Protein (antigen) binding to PLG microparticles was influenced by both electrostatic interaction and other mechanisms such as van der Waals forces. The protein binding capacity was directly proportional to the available surface area and may have a practical upper limit imposed by the formation of a complete protein monolayer as suggested by AFM images. The protein affinity for the PLG surface depended strongly on the isoelectric point (pI) and electrostatic forces, but also showed contributions from nonCoulombic interactions. Protein antigens were adsorbed on anionic PLG microparticles with varying degrees of efficiency under different conditions such as pH and ionic strength. Observable changes in zeta potentials and morphology suggest the formation of a surface monolayer. Antigen binding and release occur through a combination of electrostatic and van der Waals interactions occurring at the polymer-solution interface.
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PMID:An investigation of the factors controlling the adsorption of protein antigens to anionic PLG microparticles. 1620 Jun 15

To create porous scaffolds releasing in a controlled and independent fashion two different proteins, a novel approach based on protein-loaded polymeric coatings was evaluated. In this process, two water-in-oil emulsions are forced successively through a prefabricated scaffold to create coatings, containing each a different protein and having different release characteristics. In a first step, a simplified three-layered system was designed with model proteins (myoglobin and lysozyme). Poly(ether-ester) multiblock copolymers were chosen as polymer matrix, to allow the diffusion of proteins through the coatings. The model system showed the independent release of the two proteins. The myoglobin release was tailored from a burst to a linear release still on-going after 60 days, while the lysozyme release rate was kept constant. Macro-porous scaffolds, with a porosity of 59 vol.%, showed the same ability to control the release rate of the model proteins independently. The relation between the coatings properties and their release characteristics were investigated with the use of a mathematical diffusion model based on Fick's second law. It confirmed that the multiple coated scaffolds are biphasic system, where each coating controls the release of the protein that it contains. This approach could be of value for tissue engineering applications.
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PMID:Dual release of proteins from porous polymeric scaffolds. 1645 49

Poly(epsilon-caprolactone) (PCL)/chitin and PCL/chitosan blend films with compositional gradients were successfully fabricated by a dissolution/diffusion method; that is, repeatedly pouring the PCL/chitin (or PCL/chitosan) blend solutions, with variable composition, onto polysaccharide layers. The compositional gradient structure in the resulting films was characterized by polarized optic microscopy, ATR-FT-IR and trans-FT-IR microscopic spectroscopy. Enzymatic degradability of the PCL/chitin and PCL/chitosan blend films with compositional gradients in the presence of lysozyme was compared with those of homogeneous films and two-layer films. It was found that the degradation rate of PCL/chitin blend films with a compositional gradient was far lower than that of the neat chitin film, whereas the degradation rate of PCL/chitosan blend films with a compositional gradient was close to that of the neat chitosan film. The suppression of the chitosan crystallization, which accelerates the enzymatic degradation, at the surface of PCL/chitosan films with a compositional gradient was much more severe than that for PCL/chitin films with a compositional gradient.
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PMID:Poly(epsilon-caprolactone)/chitin and poly(epsilon-caprolactone)/chitosan blend films with compositional gradients: fabrication and their biodegradability. 1653 61

Poly-l-lysine, poly-alpha, gamma-diaminobutyric acid and basic proteins cause efflux of betacyanin from beet root tissues to varying degrees. Membrane activities fall in the order: polylysine > poly-alpha, gamma-diaminobutyric acid > polyarginine (protamine), suggesting the importance of steric factors in side-chain to backbone relations. It was also observed that homopolymer activity > heteropolymer activity, using ribonuclease and lysozyme as examples of the latter. Among polylysines, there appears to be an optimal chain length at a molecular weight equal to 50,000. Lowered activity of larger polymers is interpreted in terms of a diffusion barrier, the cell wall.Polylysine and Ca(++) exhibit competitive kinetics, and Ca(++) otherwise is far more active than other cations. It is assumed that polylysine displaces Ca(++) from anionic centers on the membrane, but cannot confer equivalent dimensional stability, rendering the membrane leaky. The possible role of cationic shielding in ionic stabilization of the membrane was also considered. The order of divalent ion activity against polylysine was Ca(++) > Sr(++) > Mg(++), suggesting again a specific size-fit relationship.
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PMID:Regulation of betacyanin efflux from beet root by poly-L-lysine, ca-ion and other substances. 1665 19


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