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)

Bacillus subtilis W23 was infected with a clear-plaque variant of SP-10 phage, namely, SP-10c. Exogenous thymidine was not incorporated into phage DNA (even in the presence of deoxyadenosine), nor was there any transfer of thymidine nucleotides from bacterial to viral DNA. The lytic program was unaffected by concentrations of 5-fluorodeoxyuridine sufficient to reduce bacterial DNA synthesis by greater than 95%. Although these data are consistent with the interpretation that thymidine nucleotides are excluded from phage DNA, formic acid digests of SP-10c DNA contained what appeared to be the four conventional bases; however, adenine and thymine were not recovered in equimolar yields. DNA-RNA hybridization and hybridization competition experiments were done. Synthesis of host RNA started to wane moments postinfection and stopped completely by 36 min. SP-10c coded for discrete classes of early and late RNA. The possibility of discrete subclasses of early RNA exists. Replication of the bacterial genome appeared to terminate 12 min postinfection. Degradation of the host DNA to acid-soluble material started at 36 min and, by the end of the latent period, greater than 90% of the host chromosome was hydrolyzed. Four apparent phage-coded enzymes have been identified. A di- and triphosphatase degraded dUTP, dUDP, dTTP, and dTDP (and, to a lesser extent, dCDP and d CTP) to the corresponding monophosphates; the enzyme had no apparent activity on dATP and dGTP. SP10c also coded for a DNA-dependent DNA polymerase, lysozyme, and a nuclease that degrades native bacterial DNA. Judging from the dependence of enzyme synthesis on the time of addition of rifampin (an inhibitor of the initiation of RNA synthesis), messengers for the di- and triphosphatase, as well as the nuclease, are transcribed from promoters that start to function 6 min postinfection. Promoters for polymerase and lysozyme did not become functional until 8 and 16 min postinfection, respectively.
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PMID:SP-10 bacteriophage-specific nucleic acid and enzyme synthesis in Bacillus subtilis W23. 13 89

A chemotactic peptide CHO.Met.Leu.Phe.OH has been synthesized classically using the mixed anhydride procedure. The formyl group was introduced by coupling formic acid in the presence of dicyclohexylcarbodiimide to the partially protected triptide. The final product was obtained by treatment of the intermediate CHO.Met.Leu.Phe.OBzl with hydrogen fluoride. The ED50 of the peptide in the Boyden chamber assay was 7 x 10(-11) M; in the lysozyme release assay 2.4 x 10(-10) M and in the beta-glucuronidase release assay 2.6 x 10(-10) M. In a radioreceptor assay the ID50 of the peptide was 3.3 x 10(-10) M.
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PMID:Synthesis of Nalpha-formyl-Met-Leu-Phe-OH: an inducer of chemotaxis in peritoneal polymorphonuclear neutrophils. 42 7

A new procedure for the construction of linker scanning mutants is described. A plasmid containing the target DNA is randomly linearized and slightly shortened by a novel combination of established methods. After partial apurination with formic acid a specific nick or small gap is introduced at the apurinic site by exonuclease III, followed by nuclease S1 cleavage of the strand opposite the nick/gap. Synthetic linkers are ligated to the ends and plasmids having the linker inserted in the target DNA are enriched. Putative linker scanning mutants are identified by their topoisomer patterns after relaxation with topoisomerase I. This technique allows the distinction of plasmids differing in length by a single basepair. We have used this rapid and efficient strategy to generate a set of 32 linker scanning mutants covering the chicken lysozyme promoter from -208 to +15.
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PMID:A new method for constructing linker scanning mutants. 302 81

The influence of eight decalcifying agents on the immunoreactivity of formalin-fixed, paraffin-embedded tissue for immunoglobulins, lysozyme, factor VIII-related antigen and keratin was studied using the unlabelled antibody peroxidase-antiperoxidase (PAP) method. Limited studies were also performed on tissues fixed in acid-formalin mixtures. All tissues were stained using an indirect immunoperoxidase method with mouse monoclonal antibodies to IgM, kappa and lambda light chains. The results suggest that, with controlled trypsinization of sections, it was possible to obtain optimal immunostaining for all tested antigens, with adequate preservation of histological structure, after decalcification in neutral EDTA or 10% aqueous acetic or formic acid. Tissue treated with agents containing mineral acids exhibited variable immunoreactivity and impaired counterstaining.
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PMID:Influence of decalcifying agents on immunoreactivity of formalin-fixed, paraffin-embedded tissue. 620 29

Protein A (PA)-activity was detected in Staphylococcus aureus strain Wood 46 which had been considered to be PA-negative. This staphylococcal strain bound 28% of 125I-labelled IgG, compared with 89% by strain Cowan I. The binding activities of both S. aureus strains were saturable, time-dependent and specific. The dissociation constants of 1.6 X 10(-9) M for Wood 46 and 9.3 X 10(-8) M for Cowan I indicated a similar affinity for human IgG in both strains. The number of IgG-binding sites were estimated to be 16,970 for Wood 46 and 41,200 for Cowan I. Exposure to heat and ultrasonication reduced PA-activities of strain Cowan I, but not that of strain Wood 46. Extraction of the staphylococci with guanidine and formic acid resulted in a reduction of IgG-binding activities only in strain Wood 46. Photooxidation, trypsinization and lysozyme treatment also diminished IgG-binding of strain Wood 46 to a larger extent than that of strain Cowan I. Extracellular PA from S. aureus strains Wood 46 and Cowan I could be purified by affinity chromatography on IgG-sepharose. The purified PA preparations gave single protein bands upon SDS-polyacrylamide gel electrophoresis. Their molecular weights were 42,000 and their isoelectric points approximated 5.0.
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PMID:Characterization of immunoglobulin G binding to Staphylococcus aureus strain Wood 46. 653 38

The Bacillus subtilis spore coat is composed of at least 15 polypeptides plus an insoluble protein fraction arranged in three morphological layers. The insoluble fraction accounts for about 30% of the coat protein and is resistant to solubilization by a variety of reagents, implying extensive cross-linking. A dodecapeptide was purified from this fraction by formic acid hydrolysis and reverse-phase high-performance liquid chromatography. This peptide was sequenced, and a gene designated cotX was cloned by reverse genetics. The cotX gene encoding the dodecapeptide at its amino end was clustered with four other genes designated cotV, cotW, cotY, and cotZ. These genes were mapped to 107 degrees between thiB and metA on the B. subtilis chromosome. The deduced amino acid sequences of the cotY and cotZ genes are very similar. Both proteins are cysteine rich, and CotY antigen was present in spore coat extracts as disulfide cross-linked multimers. There was little CotX antigen in the spore coat soluble fraction, and deletion of this gene resulted in a 30% reduction in the spore coat insoluble fraction. Spores produced by strains with deletions of the cotX, cotYZ, or cotXYZ genes were heat and lysozyme resistant but readily clumped and responded more rapidly to germinants than did spores from the wild type. In electron micrographs, there was a less densely staining outer coat in spores produced by the cotX null mutant, and those produced by a strain with a deletion of the cotXYZ genes had an incomplete outer coat. These proteins, as part of the coat insoluble fraction, appear to be localized to the outer coat and influence spore hydrophobicity as well as the accessibility of germinants.
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PMID:Cloning and characterization of a cluster of genes encoding polypeptides present in the insoluble fraction of the spore coat of Bacillus subtilis. 850 31

The effect of organic acids on the aggregation of protein(s) during rapid refolding is studied. Using egg white lysozyme, it is observed that acetic acid not only prevents aggregation, but also aids the protein to refold back to its native, biologically active state. In contrast, formic acid, propionic acid and butyric acid fail to exhibit this property. Using circular dichroism spectroscopy it has been found that an 'aggregation-insensitive' partially folded intermediate state is induced in 0.35M acetic acid.
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PMID:Effect of organic acids in the prevention of aggregation on rapid refolding of proteins. 885 May 35

The cyanogen bromide (CNBr)/formic acid cleavage reactions of wild-type and trifluoromethionine (TFM)-containing recombinant lambda lysozyme were studied utilizing ESI and MALDI mass spectrometry. Detailed analysis of the mass spectra of reverse-phase HPLC-purified cleavage fragments produced from treatment of the wild-type and labeled proteins with CNBr indicated cleavage solely of methionyl peptide bonds with no observation of cleavage at TFM. N-Acetyl-TFM was also found to be resistant to reaction with CNBr, in contrast to N-acetyl-methionine. The analysis also indicated differential reactivity among the three methionine positions in the wild-type enzyme. Additionally, formylation of intact enzyme as well as peptide fragments were observed and characterized and indicated that serine, threonine, as well as C-terminal homoserine side chains are partially formylated under standard cleavage protocols.
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PMID:CNBr/formic acid reactions of methionine- and trifluoromethionine-containing lambda lysozyme: probing chemical and positional reactivity and formylation side reactions by mass spectrometry. 961 87

Peptides and proteins were separated by capillary electrophoresis (CE) in fused-silica capillaries coated with an irreversibly adsorbed monolayer of derivatized polystyrene nanoparticles. Whereas phosphate buffer, pH 3.10, enabled the highly efficient separation of basic proteins with plate counts up to 1,400,000 m-1, volatile buffer components such as formic acid or acetic acid titrated with ammonia to the desired pH had to be used for the direct coupling of CE with electrospray ionization mass spectrometry (ESI-MS). Compared to 40 mM phosphoric acid-sodium hydroxide, pH 3.10, a background electrolyte containing 125 mM formic acid-ammonia, pH 4.00, was shown to yield equivalent separation efficiency. Investigation of the influence of buffered electrolytes on the ESI-MS signal of lysozyme at pH 2.70-4.00 showed that the charge state distribution shifted to lower charge states at higher pH with a concomitant five-fold decrease in signal intensity of the most abundant signal. The presence of trifluoroacetic acid in the background electrolyte greatly increased the level of baseline noise and completely inhibited the observation of any mass signals related to proteins. Full scan spectra could be acquired from 50-500 fmol amounts of proteins during coupled CE-ESI-MS utilizing 100-125 mM formic acid-ammonia, pH 3.10. However, compared to UV detection, considerable band broadening is observed with ESI-MS detection which is mainly attributed to column overloading, band spreading in the interface, and scanning data acquisition. Finally, the major whey proteins beta-lactoglobulin A, beta-lactoglobulin B, and alpha-lactalbumin were identified in a whey drink by comparison of molecular masses determined by CE-ESI-MS to molecular masses calculated from the amino acid sequence.
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PMID:Evaluation of volatile eluents and electrolytes for high-performance liquid chromatography-electrospray ionization mass spectrometry and capillary electrophoresis-electrospray ionization mass spectrometry of proteins. II. Capillary electrophoresis. 1044 42

The solubilities of heat-denatured and reduced, S-carboxymethylated proteins have been investigated in various organic solvents. Polar, protic solvents (formic acid, trifluoroacetic acid, 3-mercaptopropionic acid) were found to be good solvents for the denatured proteins (20-40 mg ml-1), and the solubilities of the reduced, S-carboxymethylated proteins were generally higher than those of the heat-denatured forms. Most other organic solvents were less effective in solubilizing the denatured proteins. Apolar solvents did not solubilise denatured proteins, but low solubilizing powers were observed for polar, aprotic solvents. Heat-denaturation was observed to result in the formation of large intermolecular aggregates, which, for ovalbumin and lysozyme, were formed by intermolecular S-S bonds, but for bovine serum albumin involved intermolecular isopeptide bonds.
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PMID:The solubilities of denatured proteins in different organic solvents. 1062 37


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