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)

Antibacterial peptides were isolated from human peripheral granulocytes of a healthy donor who had been treated with granulocyte-colony stimulating factor (G-CSF) and cortisol. Peptides were solubilized in acidified chloroform/methanol, and partitioned in chloroform/methanol/water. Water- soluble polypeptides were separated by cation-exchange and reversed-phase chromatography. Several previously characterized antibacterial polypeptides were identified; defensins 1-3, defensin 4, lysozyme, eosinophil cationic protein, and calgranulin A. In addition, several histone fragments were isolated and exhibited activity against the Gram- positive bacterium Bacillus megaterium strain Bm11. These fragments included two C-terminal fragments of histone H1A, three C-terminal fragments of histone H1D, one fragment of histone H1B, and two fragments of histone H4. The molecular masses of both histone H1A fragments, as determined by electrospray (ES) MS, were 270 Da higher than those calculated from their amino acid sequences. The two histone H1A fragments corresponded to Lys152-Lys222 (7527 +/- 1 Da) and Lys167-Lys222 (6023 +/- 1 Da). Tandem MS (MS/MS) of the 7.5 kDa and 6.0 kDa fragments indicated that the post-translational modification is on Lys222, the epsilon-amino group of which was conjugated with the alpha-carboxyl group of the tripeptide Arg-Gly-Gly. This finding was substantiated by digestion of the 7.5-kDa polypeptide with trypsin and analysis of the resulting peptides by ES MS and MS/MS. The tripeptide Arg-Gly-Gly corresponded uniquely to the three C-terminal residues of ubiquitin, demonstrating the presence of ubiquitinated histone H1A.
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PMID:Antibacterial peptides in stimulated human granulocytes: characterization of ubiquitinated histone H1A. 1185 9

The highly conserved, ubiquitously expressed, zinc finger protein CTCF is involved in enhancer blocking, a mechanism crucial for shielding genes from illegitimate enhancer effects. Interestingly, CTCF-binding sites are often flanked by thyroid hormone response elements (TREs), as at the chicken lysozyme upstream silencer. Here we identify a similar composite site positioned upstream of the human c-myc gene. For both elements, we demonstrate that thyroid hormone abrogates enhancer blocking. Relief of enhancer blocking occurs even though CTCF remains bound to the lysozyme chromatin. Furthermore, chromatin immunoprecipitation analysis of the lysozyme upstream region revealed that histone H4 is acetylated at the CTCF-binding site. Loss of enhancer blocking by the addition of T3 led to increased histone acetylation, not only at the CTCF site, but also at the enhancer and the promoter. Thus, when TREs are adjacent to CTCF-binding sites, thyroid hormone can regulate enhancer blocking, thereby providing a new property for what was previously thought to be constitutive enhancer shielding by CTCF.
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PMID:Thyroid hormone-regulated enhancer blocking: cooperation of CTCF and thyroid hormone receptor. 1266 Jan 64

Expression of the chicken lysozyme gene is upregulated during macrophage differentiation and reaches its highest level in bacterial lipopolysaccharide (LPS)-stimulated macrophages. This is accompanied by complex alterations in chromatin structure. We have previously shown that chromatin fine-structure alterations precede the onset of gene expression in macrophage precursor cells and mark the lysozyme chromatin domain for expression later in development. To further examine this phenomenon and to investigate the basis for the differentiation-dependent alterations of lysozyme chromatin, we studied the recruitment of transcription factors to the lysozyme locus in vivo at different stages of myeloid differentiation. Factor recruitment occurred in several steps. First, early-acting transcription factors such as NF1 and Fli-1 bound to a subset of enhancer elements and recruited CREB-binding protein. LPS stimulation led to an additional recruitment of C/EBPbeta and a significant change in enhancer and promoter structure. Transcription factor recruitment was accompanied by specific changes in histone modification within the lysozyme chromatin domain. Interestingly, we present evidence for a transient interaction of transcription factors with lysozyme chromatin in lysozyme-nonexpressing macrophage precursors, which was accompanied by a partial demethylation of CpG sites. This indicates that a partially accessible chromatin structure of lineage-specific genes is a hallmark of hematopoietic progenitor cells.
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PMID:Developmentally regulated recruitment of transcription factors and chromatin modification activities to chicken lysozyme cis-regulatory elements in vivo. 1277 78

An improved size-exclusion chromatography (SEC) was developed to isolate extremely basic (alkaline) proteins, such as trypsin (pI=10.5), lysozyme (pI=11), and histone (pI=10.8). Develosil 300 Diol-5 (300 x 8 mm I.D., 30 nm average pore diameter) column was used with an eluent of 0.1 M sodium phosphate, 1.5 M sodium chloride, glycerol (40%, v/v), 2-propanol (10%, v/v), and Brij-58 (1%, v/v). Under these conditions, the final apparent pH becomes to 4.0, and pH adjustment is not necessary. Column temperature and flow rate were 15 degrees C and 0.2 ml/min, respectively. This elution system is stable and reliable, and applications onto human pancreatic juice, human bile, and tissue homogenates were successfully achieved. Since this system is convenient for protein analysis, it is expected to be generally applicable to clinical and biochemical research for identifying protein components in combination with microsequencing.
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PMID:Size-exclusion chromatography of biological samples which contain extremely alkaline proteins. 1283 74

PHAGOCYTIN AND HISTONE DIFFER SIGNIFICANTLY IN THE FOLLOWING REGARDS: (a) the bactericidal action of histone is rapidly lost on peptic digestion, while that of phagocytin is but little affected; (b) the lethal effect of phagocytin on coliform bacteria is much more resistant than that of histone to antagonism by spermine or by increasing ionic strength of the medium; (c) phagocytin can be extracted from disrupted granulocytes with dilute citric acid whereas effective extraction of histone requires stronger mineral acid or strong salt solution; (d) phagocytin is limited in distribution to polymorphonuclear leucocytes while histone is demonstrable in many tissues. A new technique has been devised which permits extraction of phagocytin essentially free of lysozyme and histones. Phagocytin thus prepared kills certain Gram-positive bacteria as well as Gram-negative bacilli under appropriate in vitro test conditions. Among susceptible Gram-positive microbes are Group A streptococci and staphylococci. Phagocytin is demonstrable in citric acid extracts of granulocytes obtained from rabbit, man, horse, and guinea pig, the only species thus far investigated. Circulating blood leucocytes as well as exudate cells contain this bactericidal substance. The lethal effects of phagocytin on bacteria may be influenced, depending on the particular microorganism, by either pH or ionic strength of the medium. The bactericidal action of phagocytin is only slightly reduced following digestion with trypsin, chymotrypsin or papain. The active ingredient is, however, non-dialyzable and apparently precipitated by trichloracetic acid. Data available at present are insufficient to define the chemical nature of phagocytin.
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PMID:Further studies on preparation and properties of phagocytin. 1371 81

The basic proteins protamine (sulfate), histone, lysozyme, and ribonuclease were found to be potent inhibitors of mammalian heart muscle cytochromec oxidase. Their inhibitions were completely reversed in the presence of a strongly anionic polyglucose sulfate. With fresh rat heart muscle homogenates, Keili and Hartree type of beef heart muscle particulates, and deoxycholate-solubilized oxidase preparations, the reversible nature of the phenomenon was demonstrated with manometric and spectrophotometric assays for cytochrome c oxidase.
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PMID:Reversible inhibition of beef heart cytochrome c oxidase by polyionic macromolecules. 1443 70

Inhibitory action of basic esterified milk whey proteins [methylated (Met) or ethylated (Et) beta-lactoglobulin (BLG) and alpha-lactalbumin (ALA)], basic native proteins (chicken egg white lysozyme and calf thymus histone), and basic protein-like substances (L-polylysines) against the activity and replication of lactococcal bacteriophages (bIL66, bIL67, and bIL170) was tested. Chemical interactions of these proteins with phage DNA were determined as well as their protective effect on the growth of a laboratory plasmid-cured Lactococcus lactis subjected to an infection by the bacteriophages. All the proteins studied showed inhibitory activity against the three bacteriophages as tested by marked reduction of their lytic activities and decreasing the replication of studied phages. Histone and Met-BLG were more active toward bIL66 and bIL67, respectively, while both proteins were highly and equally active toward bIL170. Lysozyme showed lower antiviral activity. Antiviral activity of Et-BLG was a little bit lower than that observed in the case of the Met derivative. Esterified ALA also showed considerable but slightly lower antiviral activity as compared to other proteins. L-polylysines also showed an antiviral effect against the three bacteriophages studied, their influence being highly dependent on their molecular size. The best effective size of L-polylysines was in the range 15-70 kDa. Replication of bIL67 was inhibited by the presence of esterified ALA or BLG and native basic proteins. Complete inhibition of replication of bIL67 occurred when using polylysines with molecular masses in the ranges 4-15, 15-30, and 30-70 kDa, while protein-like substrates with lower molecular masses had only a slight effect. The presence of histone and Met-BLG at a concentration of 0.13 mg/mL in the incubation medium protected L. lactis against lysis when it was subjected to an infection by bIL67 (10(5) pfu/mL). The same action was achieved by l-polylysine (15-30 kDa) used at a concentration of 0.03 mg/mL in the incubation medium.
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PMID:Esterified whey proteins can protect Lactococcus lactis against bacteriophage infection. Comparison with the effect of native basic proteins and L-polylysines. 1585 27

It is now well established that locus-wide chromatin remodeling and dynamic alterations of histone modifications are required for the developmentally regulated activation of tissue-specific genes. However, little is known about the dynamics of these events during cell differentiation and how chromatin of an entire gene locus responds to signal transduction processes. To address this issue we investigated chromatin accessibility, linker histone distribution, and the histone methylation status at the macrophage-specific chicken lysozyme locus and the ubiquitously expressed gas41 locus in multipotent precursor cell lines and BM2 monoblast cells. The latter can be induced to go through macrophage maturation by treatment with phorbol-12-myristate acetate and can be further stimulated with bacterial lipopolysaccharide. We show that expression of the lysozyme gene in undifferentiated monoblasts is low and that a high level of gene expression requires both cell differentiation and lipopolysaccharide stimulation. However, depletion of the linker histone H1 is observed already in lysozyme non-expressing multipotent precursor cells. In undifferentiated monoblasts, the lysozyme regulatory regions are marked by the presence of monomethylated histone H3 lysine 4, which becomes increasingly converted into trimethylated H3 lysine K4 during cell differentiation. We also present evidence for extensive, differentiation-dependent alterations in nuclease accessibility at the lysozyme promoter without alterations of nucleosome and transcription factor occupancy.
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PMID:Differentiation-dependent alterations in histone methylation and chromatin architecture at the inducible chicken lysozyme gene. 1592 88

Two carboxylate-substituted, fluorescent (Phi = 0.08), water-soluble poly(p-phenyleneethynylene)s (PPE) and a water-soluble model compound were exposed to a series of proteins and bovine serum. While the anionic PPEs do not have any specific binding sites, they form stable complexes with histone, lysozyme, myoglobin, and hemoglobin. The complex formation was evidenced by fluorescence quenching. Bovine serum albumin does not quench the fluorescence of the PPEs but enhances it, probably due to its surfactant character. These results imply that the use of charged conjugated polymers as biosensors, while an attractive proposition, has to take into account strong nonspecific interactions between conjugated polymers and the host of proteins that is found in cells and complex biological fluids.
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PMID:Nonspecific interactions of a carboxylate-substituted PPE with proteins. A cautionary tale for biosensor applications. 1608 10

Increases in phenylalanine ammonia lyase activity and pisatin synthesis were induced in excised pea pods (a) by basic polypeptides such as protamine, histone, lysozyme, cytochrome c, and ribonuclease; (b) by the polyamines spermine, spermidine, cadaverine, and putrescine, and (c) by the synthetic oligopeptides poly-l-lysine, poly-dl-ornithine, and poly-l-arginine.Poly-l-lysine (1 milligram per milliliter, molecular weight 7,200) was utilized as a model inducer of pisatin and phenylalanine ammonia lyase. The poly-l-lysine-induced responses could be inhibited by adding the RNA synthesis inhibitors cordycepin or alpha-amanitin to the pods prior to or at the time of inducer application. Cordycepin added 1.5 hours after inducer no longer completely inhibited induction. The application of poly-l-lysine was shown to characteristically change the rate of RNA synthesis within 30 minutes. Ultrastructural changes in pea nuclei were detected within 3 hours, and gross changes in nuclear morphology were apparent at 14 hours after inducer application. The physical appearance of uranyl acetate-stained chromatin isolated from poly-l-lysine 2 hours after inducer application differed from that of water-treated tissues. The template properties of chromatin extracted from pods 3 hours after inducer application were consistently superior to control chromatin when assayed with Escherichia coli RNA polymerase (without sigma factor). Chromatin from poly-l-lysine-induced tissue also bound 49% more actinomycin D-(3)H.The DNA-complexing properties of inducer compounds and the induced changes in the template and dye-binding properties of pea chromatin formed the basis for a proposed mode of action for phytoalexin induction.
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PMID:Mode of Pisatin Induction: Increased Template Activity and Dye-binding Capacity of Chromatin Isolated from Polypeptide-treated Pea Pods. 1665 52


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