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Query: UNIPROT:P15088 (
mast cell
)
14,925
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
To enhance the already high quality of diffraction data for crystals of the hydrophobic protein crambin, X-ray data were collected at 130 K by the method of H. Hope to 0.83 A resolution. Refinement with PROLSQ yields a model with an R value of 10.5%. The final model had three parameter anisotropic vibration factors for all atoms, which included 367 protein heavy atoms, 372 hydrogen atoms and 144 solvent atoms with one ethanol molecule. Dihedral angles and hydrogen-bonding distances generally agree with earlier studies of high-resolution protein structures, but some new patterns are noted. Solvent-related helix distortions are reminiscent of those described by others. Helix and beta-sheet regions show distinct patterns in their side-chain conformations. Despite crambin's hydrophobic nature, its accessible surface area in the crystal is surprisingly close to that of water-soluble proteins like myoglobin and
carboxypeptidase A
. More of crambin's hydrophobic surface is buried in the crystal, perhaps accounting for its high order of diffraction. A total of 24% of the 46 residues show discrete disorder at 130 K. This includes five side-chains at both 300 and 130 K, and six more side-chains and an ethanol molecule at 130 K. Disorder is associated with the sequence microheterogeneity at Pro/Ser22 and Leu/Ile25, with space filling or with solvent disorder. Correlated conformations extend over three to five residues. The patterns of disorder in this structure reveal important principles of protein structure and its dynamics. Finding disordered groups correlated over 5 to 8 A suggests that co-ordinated motion extends in groups rather than simply as uncorrelated movement around an atom center. Thermal diffuse scattering experiments on insulin and
lysozyme
are consistent with this interpretation. Nearly all of the protein-bound solvent has been located. Less than 1% of protein accessible surface area remains uncovered by solvent or crystal contacts. Preliminary analysis of the solvent network reveals two main networks in each of four solvent regions.
...
PMID:Atomic resolution (0.83 A) crystal structure of the hydrophobic protein crambin at 130 K. 845 May 43
The sporulation-related gamma-D-glutamyl-(L)meso-diaminopimelic-acid-hydrolysing peptidase I of Bacillus sphaericus NCTC 9602 has been analysed by proton-induced X-ray emission. It contains 1 equivalent Zn2+ per mol of protein. As derived from gene cloning and sequencing, the B. sphaericus Zn peptidase I is a two-module protein. A 100-amino-acid-residue N-terminal domain consisting of two tandem segments of similar sequences, is fused to a 296-amino-acid-residue C-terminal catalytic domain. The catalytic domain belongs to the Zn
carboxypeptidase A
family, the closest match being observed with the Streptomyces griseus carboxypeptidase [Narahashi (1990) J. Biochem. 107, 879-886] and with the family prototype, bovine
carboxypeptidase A
. The catalytic domain of the B. sphaericus peptidase I possesses, distributed along the amino-acid sequence, peptide segments, a triad His162-Glu165-His307 and a dyad Tyr347-Glu366 that are equivalent to secondary structures, the zinc-binding triad His69-Glu72-His196 and the catalytic dyad Tyr248-Glu270 of bovine
carboxypeptidase A
respectively. The N-terminal repeats of the B. sphaericus peptidase I have similarity with the C-terminal repeats of the Enterococcus hirae
muramidase
2, the Streptococcus (now Enterococcus) faecalis autolysin and the Bacillus phi PZA and phi 29 lysozymes, to which a role in the recognition of a particular moiety of the bacterial cell envelope has been tentatively assigned. Detergents enhance considerably the specific activity of the B. sphaericus peptidase I.
...
PMID:Characterization of the sporulation-related gamma-D-glutamyl-(L)meso-diaminopimelic-acid-hydrolysing peptidase I of Bacillus sphaericus NCTC 9602 as a member of the metallo(zinc) carboxypeptidase A family. Modular design of the protein. 850 90
Eighteen synthetic xanthone derivatives were tested for their inhibitory effects on the activation of mast cells and neutrophils. 1,3- and 3,5-Dihydroxyxanthone showed strong inhibitory effects on the release of beta-glucuronidase and histamine from rat peritoneal mast cells stimulated with compound 48/80. 1,6-Dihydroxyxanthone and 1,3,8-trihydroxyxanthone showed strong inhibitory effects on the release of beta-glucuronidase, and beta-glucuronidase and
lysozyme
, respectively, from rat neutrophils stimulated with formyl-Met-Leu-Phe (fMLP). 1,3- and 1,6-Dihydroxyxanthone, 1,3,7-trihydroxyxanthone, and 1,3,5,6-, 2,3,6,7-, and 3,4,5,6-tetrahydroxyxanthone showed potent inhibitory effects on superoxide formation of rat neutrophils stimulated with fMLP. 1,6- and 3,5-Dihydroxyxanthone showed remarkable inhibitory effects on hind-paw oedema induced by polymyxin B in normal as well as in adrenalectomized mice. These data indicated that the anti-inflammatory effect of these compounds is mediated through the suppression of chemical mediators released from
mast cell
and neutrophil degranulation.
...
PMID:Synthesis and anti-inflammatory effects of xanthone derivatives. 879 82
To date, the diagnosis of
mast cell
disease (MCD) relied on routine plus histochemical stains. Its differential diagnosis, however, includes a variety of other hematopoietic and particularly B-cell lymphoid neoplasms that are best identified in paraffin sections using immunostains. To determine the paraffin-section immunoreactivity of MCD, 20 specimens from 14 patients with MCD and 1 bone marrow sample (from a patient with probable MCD) that showed equivocal metachromasia, were stained with antitryptase, CD68 (KP-1), CD20 (L26), antilysozyme, and antimyeloperoxidase antibodies. Ten hairy cell leukemias (HCLs), six lymphomas of parafollicular and/or monocytoid B-cell (MBCLs) and low-grade mucosa-associated lymphoid tissue (MALT) types, six granulocytic sarcomas, and five acute myeloid leukemias with monocytic differentiation (M4 and M5 types) were also stained. Tryptase positivity was identified in all of the MCD cases. The staining was moderate to strong in 20 of the 21 specimens, including the probable MCD case. No other neoplasms tested were tryptase positive. CD68 showed similar to even stronger staining in all of the specimens of MCD, HCL, granulocytic sarcoma, and acute myeloid leukemia (M4 and M5 types) tested and in five of the six MBCL and/or MALT-type lymphomas. Weak-to-moderate
lysozyme
staining seemed to be present in at least 7 of the MCD specimens, whereas there was a lack of staining for myeloperoxidase in 12 specimens, and 7 specimens were nonevaluable (1 case was not tested). Myeloperoxidase was identified in all of the granulocytic sarcomas and acute myeloid leukemias (M4 and M5 types) but not in any HCLs, MBCLs, or low-grade lymphomas of MALT type. CD20 was negative in all of the MCD and myelomonocytic neoplasms but positive in all of the HCLs, MBCLs, and low-grade B-cell lymphomas of MALT type. MCD, therefore, has a characteristic tryptase-positive, CD68-positive, and CD20-negative phenotype in paraffin sections. This distinguishes MCD from the hematopoietic and/or lymphoid disorders that it most closely resembles.
...
PMID:Immunohistochemical characterization of mast cell disease in paraffin sections using tryptase, CD68, myeloperoxidase, lysozyme, and CD20 antibodies. 890 35
Neutrophils contain various antibacterial polypeptides and proteins in the granules. Defensins have been known as the major antimicrobial granular components. Recently, we have purified a novel cationic antibacterial polypeptide of 11 kDa (CAP11) from guinea pig neutrophil granules. In this study, we have examined the extracellular release and biological activity of CAP11, and compared with defensins. CAP11 was extracellularly released from neutrophils by N-formyl Met-Leu-Phe, phorbol 12-myristate 13-acetate, accompanied by the release of
lysozyme
, a specific and azurophil granule component, without release of beta-glucuronidase, an azurophil granule component, whereas defensins were released by phagocytosis, accompanied by the release of beta-glucuronidase, suggesting that the localization of CAP11 and defensins is different among neutrophil granules. Defensins increased neutrophil adhesion, and inhibited phagocytosis of opsonized zymosan particles and phagocytosis-associated superoxide anion generation. In contrast, CAP11 did not affect these neutrophil functions. Both CAP11 and defensins possessed the histamine-releasing activities for mast cells, but CAP11 was 10-fold less potent than defensins. CAP11 and defensins showed the antibacterial activities against both Escherichia coli and Staphylococcus aureus. However, the antibacterial activity of defensins was completely lost in the presence of physiological concentration of NaCl (0.15 M), although CAP11 retained the antibacterial activity even in the presence of NaCl. Furthermore, CAP11 exhibited the 10-fold more potent antiretroviral activity than defensins against Moloney murine leukemia viruses. Together these observations indicate that when released from neutrophils, CAP11 likely functions as an antimicrobial molecule in the extracellular milieu, whereas defensins may participate in the modulation of neutrophil function and
mast cell
histamine release.
...
PMID:Comparative studies on the extracellular release and biological activity of guinea pig neutrophil cationic antibacterial polypeptide of 11 kDa (CAP11) and defensins. 908 Jun 67
1,3-beta-D-glucans (glucans) are structural elements in the cell walls of yeast and fungi with immunomodulatory properties, mediated through their ability to activate macrophages. This study assessed the activation of cells of the peritoneal cavity between 3 and 90 days after i.p. injection of particulate yeast glucan differing in molecular weight (MW) and degree of (1,6)-linkages. Female QS mice, 7-9 weeks of age, were injected, i.p., with varying doses of low (< 5 x 10(5)), medium (1-2 x 10(6)) or high (> 3 x 10(6)) MW glucans, all with low (< 5%) beta-(1,6)-linkages, or high MW (> 3 x 10(6)) glucan with high 1,6-linkages (> 20%). All glucans induced a transient increase in the proportion of neutrophils and eosinophils and a reduction in
mast cell
numbers in the peritoneal cavity. Peritoneal macrophages showed an altered morphology, increased intracellular acid phosphatase, increased LPS-stimulated NO production and increased PMA-stimulated superoxide production. There were no significant changes in serum
lysozyme
levels. Most macrophage activities returned to control levels by 28 days post injection of 1, 3-beta-D-glucan. There was a trend for higher MW or (1,6)-linked, (1, 3)-beta-D-glucans to be more stimulatory. It was concluded that particulate yeast (1,3)-beta-D-glucan is an effective stimulator of immune function, the efficiency of which may be influenced by the MW and degree of (1,6)-linkages.
...
PMID:The effect of molecular weight and beta-1,6-linkages on priming of macrophage function in mice by (1,3)-beta-D-glucan. 1054 Feb 5
Bacteriophage T7
lysozyme
binds to T7 RNA polymerase (RNAP) and regulates its transcription by differentially repressing initiation from different T7 promoters. This selective repression is due in part to a
lysozyme
-induced increase in the KNTP of the initiation complex (IC) and to intrinsically different NTP concentration requirements for efficient initiation from different T7 promoters. While
lysozyme
represses initiation, once the enzyme has left the promoter and formed an elongation complex (EC) it is generally resistant to the effects of
lysozyme
. The mechanism by which the inhibitory effects of
lysozyme
are largely restricted to the initiation phase of transcription is not well understood. We find that T7
lysozyme
destabilizes initial transcription complexes (ITCs) and increases the rate of release of transcripts from these complexes but does not destabilize ECs. However, if the RNA:RNAP interaction proposed to be important for EC stability is disrupted by proteolysis of the RNA-binding domain or use of templates which interfere with establishment of this RNA:RNAP interaction, the EC becomes sensitive to
lysozyme
. Comparison of the X-ray structures of T7RNAP and of a T7RNAP:T7
lysozyme
complex reveals that
lysozyme
causes the C terminus of the polymerase to flip out of the active site. Experiments in which
carboxypeptidase A
is used to probe the
lysozyme
-induced exposure of the C terminus reveal a large decrease in carboxypeptidase sensitivity following transcription initiation, suggesting that interactions with the 3'-end of the RNA help stabilize the active site in a functional (carboxypeptidase protected) conformation. Thus, the resistance of the EC to
lysozyme
appears to be due to the consecutive establishment of two sets of RNA:RNAP interactions. The first is made with the 3'-end of the RNA and helps stabilize a functional conformation of the active site, thereby suppressing the effects of
lysozyme
on KNTP. The second is made with a more upstream element of the RNA and keeps the EC from being destabilized by
lysozyme
binding.
...
PMID:Mechanisms by which T7 lysozyme specifically regulates T7 RNA polymerase during different phases of transcription. 1054 43
To design artificial proteases that cleave peptide backbones of a wide range of proteins at selected sites, artificial active sites comprising the Cu(II) complex of cyclen (Cu(II)Cyc) and aldehyde group were synthesized on a cross-linked polystyrene. The aldehyde group was employed as the binding site in view of its ability of reversible formation of imine bonds with epsilon-amino groups of Lys residues exposed on the surface of proteins and Cu(II)Cyc as the catalytic group for peptide hydrolysis. The two polymeric artificial metalloproteases synthesized in the present study cleaved all of the protein substrates examined (myoglobin, gamma-globulin, bovine serum albumin, human serum albumin,
lysozyme
, and ovalbumin), manifesting saturation kinetic behavior. At 50 degrees C and pH 9.0 or 9.5, K(m) was (1.3-22) x 10(-)(4) M, comparable to those of natural proteases, and k(cat) was (6.0-25) x 10(-)(4) s(-)(1), corresponding to half-lives of 4.6-19 min. Intermediacy of the imine complexes formed between the aldehyde group of the catalyst and the epsilon-amino groups of Lys residues of the substrates was confirmed by the trapping experiment with NaB(OAc)(3)H. MALDI-TOF MS of the proteolytic reaction mixtures revealed formation of various cleavage products. Structures of some of the cleavage products were determined by using
carboxypeptidase A
and trypsin. Among various cleavage sites thus identified, Gln(91)-Ser(92) and Ala(94)-Thr(95) were the major initial cleavage sites in the degradation of myoglobin by the two catalysts. The selective cleavage of Gln(91)-Ser(92) and Ala(94)-Thr(95) was attributed to general acid assistance in peptide cleavage by Tyr(146) located in proximity to the two peptide bonds. Broad substrate selectivity, high cleavage-site selectivity, and high proteolytic rate are achieved, therefore, by positioning the aldehyde group in proximity to Cu(II)Cyc attached to a cross-linked polystyrene.
...
PMID:Artificial metalloprotease with active site comprising aldehyde group and Cu(II)cyclen complex. 1598 87
Infection with Salmonella typhimurium can produce multiple organ dysfunctions. However, document concerning with gastric hemorrhagic ulcers occur in this infectious disease is lacking. The aim was to study modulation of gastric hemorrhagic ulcer by oxidative stress and
mast cell
histamine in S. typhimurium-infected rats. Additionally, the protective effects of drugs, such as ofloxacin,
lysozyme
chloride, ketotifen, ranitidine, and several antioxidants, including exogenous glutathione (GSH), allopurinol and dimethylsulfoxide (DMSO) were evaluated. Male Wistar rats were injected intrajejunally with a live culture of S. typhimurium (1 x 10(10) colony-forming units/rat) and followed by deprivation of food for 36 h. Age-matched control rats received sterilized vehicle only. Rat stomachs were irrigated for 3 h with either normal saline or a simulated gastric juice containing 100 mM HCl, 17.4 mM pepsin and 54 mM NaCl. S. typhimurium caused aggravation of offensive factors, including enhancing gastric acid back-diffusion, mucosal lipid peroxide generation, histamine release, microvascular permeability and hemorrhagic ulcer, as well as an attenuation of defensive substances, such as mucosal GSH and mucus level. Intragastric irrigation of gastric juice caused further aggravation of these gastric biochemical parameters. This exacerbation of ulcerogenic factors was abolished by pretreatment of ofloxacin and
lysozyme
chloride. Antioxidants, such as reduced GSH, allopurinol and DMSO also produced significant (P < 0.05) amelioration of gastric damage in S. typhimurium infected rats. In conclusion, gastric oxidative stress and histamine play pivotal roles in the formation of hemorrhagic ulcers that were effectively ameliorated by ofloxacin,
lysozyme
chloride, ketotifen, ranitidine, diamine oxidase and various antioxidants in S. typhimurium-infected rats.
...
PMID:Modulation of gastric hemorrhage and ulceration by oxidative stress and histamine release in Salmonella typhimurium-infected rats. 1625 43
On the basis of elastic light scattering, we have compared the capacity of the multi-block, surfactant copolymers Poloxamer 108 (P108), Poloxamer 188 (P188), and Tetronic 1107 (T1107), of average molecular weight 4700, 8400, and 15,000, respectively, with that of polyethylene glycol (PEG, molecular weight 8000) to suppress aggregation of heat-denatured hen egg white
lysozyme
(HEWL) and bovine serum albumin (BSA). We also compared the capacity of P188 to that of PEG to suppress aggregation of
carboxypeptidase A
denatured in the presence of trifluoroethanol and to facilitate recovery of catalytic activity. In contrast to the multi-block copolymers, PEG had no effect in inhibiting aggregation of HEWL or of
carboxypeptidase A
with the recovery of catalytic activity. At very high polymer:protein ratios (>or=10:1), PEG increased aggregation of heat-denatured HEWL and BSA, consistent with its known properties to promote macromolecular crowding and crystallization of proteins. At a polymer:protein ratio of 2:1, the tetra-block copolymer T1107 was the most effective of the three surfactant copolymers, completely suppressing aggregation of heat-denatured HEWL. At a T1107:BSA ratio of 10:1, the poloxamer suppressed aggregation of heat-denatured BSA by 50% compared to that observed in the absence of the polymer. We showed that the extent of suppression of aggregation of heat-denatured proteins by multi-block surfactant copolymers is dependent on the size of the protein and the copolymer:protein molar ratio. We also concluded that at least one of the tertiary nitrogens in the ethylene-1,2-diamine structural core of the T1107 copolymer is protonated, and that this electrostatic factor underlies its capacity to suppress aggregation of denatured proteins more effectively than nonionic, multi-block poloxamers. These results indicate that amphiphilic, surfactant, multi-block copolymers are efficient as additives to suppress aggregation and to facilitate refolding of denatured proteins in solution. Because of these properties, multi-block, surfactant copolymers are suitable for application to a variety of biotechnological and biomedical problems in which refolding of denatured or misfolded proteins and suppression of aggregation are important objectives.
...
PMID:Multi-block poloxamer surfactants suppress aggregation of denatured proteins. 1795 Oct 11
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