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)

Reduced numbers of frictional/scattering centers are essential for tractable hydrodynamic and small-angle scattering data modeling. We present a method for generating medium-resolution models from the atomic coordinates of proteins, basically by using two nonoverlapping spheres of differing radii per residue. The computed rigid-body hydrodynamic parameters of BPTI, RNase A, and lysozyme models were compared with a large database of critically assessed experimental values. Overall, very good results were obtained, but significant discrepancies between X-ray- and NMR-derived models were found. Interestingly, they could be accounted for by properly considering the extent to which highly mobile surface side chains differently affect translational/rotational properties. Models of larger structures, such as fibrinogen fragment D and citrate synthase, also produced consistent results. Foremost among this method's potential applications is the overall conformation and dynamics of modular/multidomain proteins and of supramolecular complexes. The possibility of merging data from high- and low-resolution structures greatly expands its scope.
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PMID:SOMO (SOlution MOdeler) differences between X-Ray- and NMR-derived bead models suggest a role for side chain flexibility in protein hydrodynamics. 1589 63

Rhizobium trifolii strains IARI and Rel-1 produced substances with broad and narrow activity spectra, respectively. Reproducible inhibitory zones of various sizes produced by R. trifolii IARI (2 to 14 mm) and R. trifolii Rel-1 (2 to 6 mm) were detected, depending upon the indicator organism used. The maximum production of these substances by both strains of R. trifolii was observed on l-arabinose agar. A preliminary characterization of the antimicrobial substance produced by strain IARI showed resistance to heat (75 to 80 degrees C for 45 min), trypsin, lysozyme, DNase I, and RNase A. On the other hand, the substance produced by strain Rel-1 showed sensitivity to heat (75 to 80 degrees C for 45 min) and trypsin, but resistance to lysozyme, RNase A, and DNase I.
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PMID:Production of Antimicrobial and Bacteriocin-Like Substances by Rhizobium trifolii. 1634 2

The separation of four proteins including RNase A, cytochrome C, lysozyme and myoglobin was investigated by reversed-phase gradient pressurized capillary electrochromatography (p-CEC) with 1.5 microm non-porous silica C18 stationary phase. This mode was compared with micro-high performance liquid chromatography (mu-HPLC) and the effects of applied voltage, stationary phase and concentration of ion-pairing agent (trifluoroacetic acid, TFA) on the gradient p-CEC were also studied. This separation was performed rapidly on a new CEC instrument Trisep 2010 GV. The results showed that the retention mechanism of proteins in p-CEC mode is based on both chromatographic partitioning and electrophoretic migration. The results also demonstrated that p-CEC may have great potential for fast and efficient separation of proteins.
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PMID:[Separation of proteins by gradient pressurized capillary electrochromatography]. 1649 3

A protein disulfide isomerase of Neospora caninum (NcPDI) with a molecular weight of 50kDa was identified in tachyzoite lysate and excretory-secretory (ES) products. The IgA antibody in 58.0% of the individual cattle tear samples recognized the NcPDI, which suggests that the PDI-specific antibody may be involved in defense against parasites. In addition, PDI-specific inhibitors and NcPDI antiserum showed inhibitory effects on the growth of N. caninum tachyzoites. Furthermore, the purified recombinant NcPDI demonstrated biological activities in vitro by catalysis and refolding of reduced RNase A and assisted in the recovery of native lysozyme. These findings indicate that NcPDI possesses PDI-specific enzymatic activity and could be a putative target for chemotherapy for neosporosis.
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PMID:Identification of a protein disulfide isomerase of Neospora caninum in excretory-secretory products and its IgA binding and enzymatic activities. 1657 26

A new class of receptor is described that can selectively bind to the solvent exposed surface of proteins such as cytochrome c and lysozyme with low micromolar affinity over cytochrome c551, alpha-lactalbumin, myoglobin and RNase A, under physiologically relevant conditions (5 mM phosphate, pH 7.4). The use of anthracene as a hydrophobic scaffold allows the receptor to act as a selective chemosensor via fluorescence quenching or FRET. The study reveals that co-operative electrostatic interactions over a large surface area dominate binding. Further investigations reveal that the receptor binds to the solvent exposed heme edge of cytochrome c inhibiting its reaction with small reducing agents and validating the strategy for the disruption of protein function.
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PMID:Recognition of solvent exposed protein surfaces using anthracene derived receptors. 1720 71

Molecular imprinting is a technique used to create specific recognition sites on the surface of materials. Although widely developed for chromatographic separation of small molecules, this approach has not been adequately investigated for biomaterial applications. Thus, the objective of these experiments was to explore the potential of molecular imprinting for creating biomaterials that preferentially bind specific proteins. Macroporous polysiloxane (silica) scaffolds were imprinted with either lysozyme or RNase A using sol-gel processing. The quantity of surface-accessible protein, which was related to the number of potential binding sites, was varied by changing the amount of protein loaded into the sol. Up to 62% of loaded protein was accessible. The amount of protein per unit surface area ranged from 0.3microgm(-2) for low loading of RNase to 152microgm(-2) for high loading of lysozyme. Protein-imprinted scaffolds were then evaluated for their ability to preferentially recognize the template biomolecule when incubated in mixtures containing both the imprinted protein and a competitor protein of comparable size (approximately 14kD). In solutions containing a single protein, up to 3.6 times more template bound compared with the competitor. Furthermore, in solutions containing equal amounts of both molecules, the porous scaffolds bound up to three times more template than the competitor protein, which is a level of preferential binding similar to values reported in the molecular imprinting literature for both organic and inorganic materials.
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PMID:Protein-imprinted polysiloxane scaffolds. 1736 50

The new small-scale cross-axis coil planet centrifuge (X-axis CPC) previously designed and fabricated in our laboratory has a distinctive feature such that four separation columns of similar weight are mounted symmetrically around the rotary frame to achieve stable balancing of the centrifuge under a high revolution speed. In this column layout, neighboring columns must be rotated in the opposite direction if viewed from the center of the centrifuge to avoid twisting the interconnecting flow tubes. The effect of rotational direction of the columns on the partition efficiency was evaluated with separation of a set of test samples such as cytochrome c, myoglobin, and lysozyme using an aqueous-aqueous polymer phase system composed of 12.5% (w/w) polyethylene glycol (PEG) 1000 and 12.5% (w/w) dibasic potassium phosphate under 1000 rpm of column revolution. A series of experiments was performed using a set of two diagonally located columns (connected in series) each consisting of five coiled layers of 1 mm I.D. with a total capacity of 27.0 mL. Both right- and left-handed coils were tested each under the optimized conditions for choice of mobile phase and direction of the column rotation so that the satisfactory volume of the mobile phase was retained in the column by the aid of Archimedean screw effect. The results of these studies showed that one particular combination of handedness of the coil and direction of the rotation yielded the best peak resolution for each mobile phase. In order to demonstrate the capability of the apparatus, the purification of ribonuclease (RNase) from the extract of bullfrog egg, sialic acid binding lectin (cSBL), was carried out using both organic-aqueous and aqueous-aqueous polymer phase systems. When using the 16.0% (w/w) PEG 1000-6.3% (w/w) dibasic potassium phosphate-6.3% (w/w) monobasic potassium phosphate system, cSBL was successfully separated from other proteins present in the extract while commercial RNase A was eluted at near the solvent front by the lower phase mobile. The cSBL retained its native RNase activity. The overall results demonstrated that the present new small-scale X-axis CPC is useful for the purification of bioactive compounds without loss of their native activities.
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PMID:New small-scale cross-axis coil planet centrifuge. Partition efficiency and application to purification of bullfrog ribonuclease. 1740 Feb 32

The use of a phenylalanine (Phe) functionalized tentacle-type polymer coated capillary column for protein separation by open tubular capillary electrochromatography (OTCEC) was demonstrated in this work. The tentacle-type stationary phase was prepared from silanized fused-silica capillaries of 50 microm I.D. by glycidyl methacrylate graft polymerization and subsequent Phe functionalization. Due to the amphoteric functional groups of the Phe bonded on the tentacle-type polymer stationary phase, protein separation in the prepared column can be performed under both cathodic and anodic electroosmotic flow (EOF) by varying the pH values of the mobile phase. Model proteins including ribonuclease A (RNase A), myoglobin, transferrin, insulin were baseline separated under cathodic EOF with a mobile phase of pH 8.8. Comparison between the separation result of the four proteins under conditions of OTCEC and capillary zone electrophoresis indicates that the migration behavior of the four proteins in the prepared column was the result of the interplay of chromatographic retention and electrophoretic migration. Besides, three basic proteins including RNase A, cytochrome c (Cyt-c) and lysozyme (Lys) were fully resolved under anodic EOF with an acidic running buffer (pH 2.5). The elution order was the same as the isoelectric point values of the proteins (RNase A<Cyt-c<Lys). Moreover, it was proved that the migration times of all the proteins used in this work were stable in repeated uses of the column, and the column efficiency of proteins was in the range from 13,000 to 182,000 plates/m.
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PMID:Protein separation by open tubular capillary electrochromatography employing a capillary coated with phenylalanine functionalized tentacle-type polymer under both cathodic and anodic electroosmotic flows. 1825 79

Although solution additives prevent protein misfolding, the mechanism remains elusive. In this paper, we compare the preventive effects of trans-1,2-cyclohexanediamine (1,2-CHDA) and trans-1,4-cyclohexanediamine (1,4-CHDA) on the heat-induced inactivation of ribonuclease A (RNase A) and lysozyme. These additives are more effective in preventing thermal inactivation of the proteins than guanidine (Gdn) and arginine (Arg). The results suggest two possibilities: (i) decrease in the hydrophobic interaction between unfolded protein molecules is indispensable for preventing protein association, and (ii) the electrostatic interaction between additives interacting with the hydrophobic residues of protein molecules plays an important role in preventing thermal inactivation of proteins.
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PMID:Trans-cyclohexanediamines prevent thermal inactivation of protein: role of hydrophobic and electrostatic interactions. 1829 69

A real-time and labeling-free surface plasmon resonance (SPR) sensor was used to monitor the conformational changes of immobilized globule proteins (RNase A and lysozyme) in chemical unfolding and refolding. The effects of chemical denaturants on the protein structures were investigated. The methodology in protein conformational study on the solid surface is refined through the theoretic calculations and the conformational information of native/denatured proteins in solution. Additionally, our observation illustrates that the ambient buffer solution is merit to influence the refractive index of immobilized protein films and directly be observed from the SPR resonance angle shifts.
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PMID:Effects of solute-matrix interaction on monitoring the conformational changes of immobilized proteins by surface plasmon resonance sensor. 1897 Feb 51


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