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)

The T4 phage capsid accessory protein genes soc and hoc have recently been developed for display of peptides and protein domains at high copy number (Ren et al., 1996. Protein Science 5, 1833-1843; Ren et al., 1997. Gene 195, 303-311). That biologically active and full-length foreign proteins can be displayed by fusion to SOC and HOC on the T4 capsid is demonstrated in this report. A 271-residue heavy and light chain fused IgG anti-EWL (egg white lysozyme) antibody was displayed in active form attached to the COOH-terminus of the SOC capsid protein, as demonstrated by lysozyme-agarose affinity chromatography (>100-fold increase in specific titer). HOC with NH2-terminal fused HIV-I CD4 receptor of 183 amino acids can be detected on the T4 outer capsid surface with human CD4 domain 1 and 2 monoclonal antibodies. The number of molecules of each protein (10-40) bound per phage and their activity suggest that proteins can fold to native conformation and be displayed by HOC and SOC to allow binding and protein-protein interactions on the capsid.
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PMID:Phage T4 SOC and HOC display of biologically active, full-length proteins on the viral capsid. 971 43

A chitinase antigen has been identified in Pseudomonas aeruginosa strain 385 using sera from animals immunized with a whole-cell vaccine. The majority of the activity was shown to be in the cytoplasm, with some activity in the membrane fraction. The chitinase was not secreted into the culture medium. Purification of the enzyme was achieved by exploiting its binding to crab shell chitin. The purified enzyme had a molecular mass of 58 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and a pI of 5.2. NH2-terminal amino acid sequencing revealed two sequences of M(I/L)RID and (Q/M/V)AREDAAAAM that gave an exact match to sequences in a translated putative open reading frame from the P. aeruginosa genome. The chitinase was active against chitin azure, ethylene glycol chitin, and colloidal chitin. It did not display any lysozyme activity. Using synthetic 4-methylumbelliferyl chitin substrates, it was shown to be an endochitinase. The Km and kcat for 4-nitrophenyl-beta-D-N,N'-diacetylchitobiose were 4.28 mM and 1.7 s(-1) respectively, and for 4-nitrophenyl-beta-D-N,N',N"-triacetylchitotriose, they were 0.48 mM and 0.16 s(-1) respectively. The pH optimum was determined to be pH 6.75, and 90% activity was maintained over the pH range 6.5 to 7.1. The enzyme was stable over the pH range 5 to 10 for 3 h and to temperatures up to 50 degrees C for 30 min. The chitinase bound strongly to chitin, chitin azure, colloidal chitin, lichenan, and cellulose but poorly to chitosan, xylan, and heparin. It is suggested that the chitinase functions primarily as a chitobiosidase, removing chitobiose from the nonreducing ends of chitin and chitin oligosaccharides.
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PMID:Identification and characterization of a chitinase antigen from Pseudomonas aeruginosa strain 385. 1152 97

Ammonia oxidation is a rate-limiting step in the biological removal of nitrogen from wastewater. Analysis of microbial communities possessing the amoA gene, which is a small subunit of the gene encoding ammonia monooxygenase, is important for controlling nitrogen removal. In this study, the amoA gene present in Nitrosomonas europaea cells in a pure culture and biofilms in a nitrifying reactor was amplified by in situ PCR. In this procedure, fixed cells were permeabilized with lysozyme and subjected to seminested PCR with a digoxigenin-labeled primer. Then, the amplicon was detected with an alkaline phosphatase-labeled antidigoxigenin antibody and HNPP (2-hydroxy-3-naphthoic acid-2'-phenylanilide phosphate), which was combined with Fast Red TR, and with an Alexa Fluor 488-labeled antidigoxigenin antibody. The amoA gene in the biofilms was detected with an unavoidable nonspecific signal when the former method was used for detection. On the other hand, the amoA gene in the biofilms was detected without a nonspecific signal, and the cells possessing the amoA gene were clearly observed near the surface of the biofilm when Alexa Fluor 488-labeled antidigoxigenin antibody was used for detection. Although functional gene expression was not detected in this study, detection of cells in a biofilm based on their function was demonstrated.
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PMID:Direct detection by in situ PCR of the amoA gene in biofilm resulting from a nitrogen removal process. 1167 54

The biological action of several X-Phe-D-Leu-Phe-D-Leu-Z (X=3',5'-dimethylphenyl-ureido; Z=Phe, Lys, Glu, Tyr) analogues was analysed on human neutrophils to evaluate their ability to antagonize formyl-peptide receptors. X-Phe-D-Leu-Phe-D-Leu-Phe analogues obtained as C-terminal olo or amido derivatives and T-Phe-D-Leu-Phe-D-Leu-Phe analogues (T=thiazolyl-ureido) were also analysed. The activities of pentapeptide derivatives were compared with those of X-Phe-D-Leu-Phe-D-Leu-Phe chosen as reference antagonist. Our results demonstrate that X-Phe-D-Leu-Phe-D-Leu-Phe-olo, X-Phe-D-Leu-Phe-D-Leu-Glu and X-Phe-D-Leu-Phe-D-Leu-Tyr are more active antagonists than X-Phe-D-Leu-Phe-D-Leu-Phe. The presence of Lys (X-Phe-D-Leu-Phe-D-Leu-Lys) seems, instead, to inhibit the formyl-peptide receptor antagonist properties. The presence of the N-terminal thiazolyl-ureido group seems to considerably contribute to the receptor antagonist properties of T-Phe-D-Leu-Phe-D-Leu-Phe-OH. The introduction of the C-terminal methyl ester (T-Phe-D-Leu-Phe-D-Leu-Phe-OMe) or amido group (X-Phe-D-Leu-Phe-D-Leu-Phe-NH2) appears detrimental for the affinity and formyl-peptide receptor antagonist properties of the Phe-D-Leu-Phe-D-Leu-Phe derivatives. The examined peptides inhibit superoxide anion production and lysozyme release more efficaciously than neutrophil chemotaxis.
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PMID:C- and N-terminal residue effect on peptide derivatives' antagonism toward the formyl-peptide receptor. 1185 98

Immobilization of biomolecules on surfaces enables both localization and retention of molecules at the cell-biomaterial interface. Since metallic biomaterials used for orthopedic and dental implants possess a paucity of reactive functional groups, biomolecular modification of these materials is challenging. In the present work, we investigated the use of a plasma surface modification strategy to enable immobilization of bioactive molecules on a "bioinert" metal. Conditions during plasma polymerization of allyl amine on Ti-6Al-4V were varied to yield 5 ("low")- and 12 ("high")-NH2/nm2. One- and two-step carbodiimide schemes were used to immobilize lysozyme, a model biomolecule, and bone morphogenetic protein-4 (BMP-4) on the aminated surfaces. Both schemes could be varied to control the amount of protein bound, but the one-step method destroyed the activity of immobilized lysozyme because of crosslinking. BMP-4 was then immobilized using the two-step scheme. Although BMP bound to both low- and high-NH2 surfaces was initially able to induce alkaline phosphatase activity in pluripotent C3H10T1/2 cells, only high amino group surfaces were effective following removal of weakly bound protein by incubation in cell culture medium.
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PMID:A technique to immobilize bioactive proteins, including bone morphogenetic protein-4 (BMP-4), on titanium alloy. 1199 50

The phase behavior of a thermoseparating cationic hydrophobically modified ethylene oxide polymer (HM-EO) containing tertiary amines has been investigated at different pH, salt and sodium dodecyl sulfate (SDS) concentrations, in order to find a water/HM-EO two-phase system suitable for protein partitioning. The used polymer forms micellar aggregates that can be charged. By changing pH and SDS concentrations the netcharge of the SDS/HM-EO aggregate can be shifted from positive to negative. Bovine serum albumin (BSA) and lysozyme were partitioned in the thermoseparated two-phase systems of the cationic polymer at different pH, salt and SDS concentrations. The dominant attractive interactions between the polymer aggregates and the studied proteins were shown to be of electrostatic (Coulomb) nature rather than hydrophobic interaction. At low ionic strength the positively charged polymeric aggregates attracted negatively charged BSA and repelled positively charged lysozyme. Upon addition of SDS the negatively charged aggregates attracted lysozyme and repelled BSA. Thus, it was possible to direct proteins with different charges to the polymeric phase and redirect them to a polymer-depleted phase by changing the netcharge of the polymeric aggregates. The effect of different salts on the partitioning of BSA in a system of slightly positively charged HM-EO was studied. NaCl and KBr have a significant effect on driving the BSA to the polymer-depleted phase, whereas KF and K2SO4 have a smaller effect on the partitioning. The cloud point temperature of the charged polymer decreased upon addition of SDS near the isoelectric molar ratio of SDS to polymer and also upon salt addition. In the latter case the decrease was smaller than expected from model calculations based on Flory-Huggins theory, which were performed for a charged thermoseparating polymer at different charges and salt concentrations.
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PMID:Protein partitioning in thermoseparating systems of a charged hydrophobically modified ethylene oxide polymer. 1256 77

The progressive reduction of charge in charge states of non-denatured proteins (lysozyme, ubiquitin, and cytochrome c), observed with nanospray in the positive ion mode, when the buffer salt ammonium acetate is replaced by ethylammonium acetates (EtNH(3)Ac, Et(2)NH(2)Ac and Et(3)NHAc) is rationalized on the basis of the charge residue model (CRM). The charge states of the multiply protonated protein are shown to be controlled by the increasing gas-phase basicities, GB(B), of the bases(B) NH(3), EtNH(2), Et(2)NH and Et(3)N. Charge states derived from evaluated apparent gas-phase basicities GB(app) of the basic side-chains of the protein and the known GB(B) of the above bases are found to be in agreement with the experimentally observed charge states. This is a requirement of the CRM, because in this model the small positive ions (the buffer cations in the present case) at the surface of the electrospray droplets are the excess ions that provide the charge of the final small droplet that contains the protein molecule and on evaporation of the solvent transfer the charge to the protein. The observed charge states in the absence of buffer salts, i.e. pure water, are attributed to excess H(3)O(+) ions produced by the electrolysis process that attends electrospray. A proposed extended mechanism provides predictions of factors that determine the sensitivity for detection of the multiply protonated proteins. Consideration of restraints imposed by the CRM lead to some simple predictions for conditions that should be present to obtain accurate determinations by electrospray and nanospray of stability constants for the protein-complex equilibrium in aqueous solution.
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PMID:Effect of buffer cations and of H3O+ on the charge states of native proteins. Significance to determinations of stability constants of protein complexes. 1282 31

Wiley, W. R. (Washington State University, Pullman), and J. L. Stokes. Effect of pH and ammonium ions on the permeability of Bacillus pasteurii. J. Bacteriol. 86:1152-1156. 1963.-Cell suspensions of Bacillus pasteurii require an alkaline pH (8.5 to 9.0) and NH(4) (+) for the oxidation of low concentrations (4 mum) of fumaric acid, glutamic acid, alanine, and other oxidizable substrates. In contrast, cells disrupted by a French press or by lysozyme oxidize these substrates at pH 7.2 and without NH(4) (+). Moreover, the alkaline pH and NH(4) (+) inhibit substrate oxidation by the broken cells. These striking differences between whole and disrupted cells suggest that pH and NH(4) (+) affect whole cells externally and not internally. It appears that the alkaline pH is needed to convert NH(4) (+) to free NH(3). The latter in turn is required by the cells for the transport of low concentrations of substrate across the cell membrane. At high concentrations (20 to 250 mum), substrates force entry into the cells by simple diffusion, thereby eliminating the need for a high pH and NH(4) (+) for oxidation.
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PMID:EFFECT OF PH AND AMMONIUM IONS ON THE PERMEABILITY OF BACILLUS PASTEURII. 1408 82

An MIP-QCM sensor able to detect micro-determine albumin concentrations was prepared by imprinting albumin with 3-dimethylaminopropyl methacrylamide-acrylate. The albumin MIP was coated on a QCM Au electrode. The adsorption characteristics of different electrodes, such as Au-OH, Au-COOH, Au-NH2 and Au electrodes, with albumin or mixture was examined. In the tetraethyleneglycol dimethacrylate crosslinking agent system, the adsorption capacity of different Au electrodes is in the order Au-OH > Au-COOH > Au-NH2 > Au. Additionally, the time taken to receive a steady-state frequency is in the order Au-NH2 < Au-OH < Au-COOH < Au. However, in the trimethylolpropane trimethacrylate crosslinking agent system, the adsorption capacity is in the order Au > Au-NH2 > Au-OH > Au-COOH electrode. Hence, the crosslinking agent had a significant effect on the MIP-QCM. On the adsorption selectivity, the albumin MIP-QCM exhibited higher response to albumin, the adsorption mass ratio of cytochrome c:lysozyme:albumin:myoglobin was 160:1:1942:30. On the other hand, in the non-MIP-QCM, the adsorption mass ratio of cytochrome c:lysozyme:albumin:myoglobin was 13:1:249:86. Additionally, a linear fitting was established and a clinical real sample was tested. This novel potential application of molecular imprinting to the recognition element of an MIP-QCM sensor appears to be promising.
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PMID:Determination of albumin concentration by MIP-QCM sensor. 1514 79

This study exploits the increase in chromatographic retention that accrues from benzoyl derivatization of primary amines as a tool to increase sequence coverage in tryptic peptide mapping. N-hydroxysuccinamide sulfonyl benzoate quantitatively derivatizes primary amines of peptides. Introduction of the hydrophobic benzoyl moiety into peptides increased retention of peptides during reversed-phase chromatography (RPC), particularly in the case of smaller hydrophilic peptides. Short chain (1-6 amino acids) tryptic fragments of model proteins lysozyme, myoglobin, and cytochrome c derivatized with N-hydroxysuccinamide sulfonyl benzoate eluted in the linear acetonitrile gradient. Application of benzoyl derivatization was further extended to achieve complete sequence coverage of a therapeutic protein, recombinant human growth hormone, and in detection of single amino acid polymorphism.
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PMID:Benzoyl derivatization as a method to improve retention of hydrophilic peptides in tryptic peptide mapping. 1545


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