Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to be used as fertility regulators in humans, gonadotropin releasing hormone (GnRH) antagonists must be extremely potent and long acting and exhibit negligible side effects such as stimulating histamine release. To this aim, we have recently synthesized a series of analogues with the standard Ac-DNal1-DCpa2-DPal3 substitutions, where the N omega-amino function of ornithine, lysine, or p-aminophenylalanine (Aph) was converted to the aminotriazolyl (atz) derivatives at positions 5 and 6 with further modifications at positions 7 and 10. The analogues were tested for their ability to bind to pituitary cell membranes, to release histamine in a mast cell assay, to inhibit luteinizing hormone (LH) secretion by castrated male rats or cultured pituitary cells, and to interfere with the ovulation in intact female rats. While the subcutaneous (sc) injection of 50 micrograms of Azaline A (7, [Ac-DNal1,DCpa2,DPal3,Lys5(atz),DLys6++ +(atz),ILys8,DAla10]GnRH) dissolved in 0.2 mL of an aqueous media significantly inhibited LH release in the castrated male rat for 24 h, the same dose of Azaline B (11), [Ac-DNal1,DCpa2,DPal3,Aph5(atz),DAph6++ +(atz),ILys8,DAla10]GnRH, inhibited LH release for 72 h. A similar long duration of action was observed for Antide ([Ac-DNal1,DCpa2,DPal3,Lys5(Nic),DLys6(Nic ),ILys8,DAla10]GnRH) but not for Nal-Glu ([Ac-DNal1,DCpa2,DPal3,Arg5,4-(pmethoxybenzoy l)-D-2-Abu6,DAla10]GnRH). In the same paradigm, a 5-fold dilution of the peptide (50 micrograms in 1 mL) and the use of three injection sites rather than one resulted in significantly shorter duration of action for most of the peptides tested. This suggested that long duration of action might be the result of slow release from the injection site(s). In order to investigate this possibility, Nal-Glu and Azaline B were injected intravenously (i.v.) at three doses (10, 50, 250 micrograms) to castrated male rats. At all doses, both peptides significantly lowered LH levels for 8 h. By 24 h, Nal-Glu (250 micrograms) and Azaline B (50 and 250 micrograms) still measurably inhibited LH secretion. Finally, only Azaline B (250 micrograms) was still active at 48 h. These findings demonstrate that subtle structural modifications will yield peptides with different half-lives after iv administration. These findings led us to investigate the effects of other structural modifications on duration of action. We observed that systematic substitutions at positions 7 (NMeLeu) and 10 (Pro9-NHEt, and Gly-NH2) were found to be deleterious. Of interest was the observation that only the DAla10-NH2 substitution led to long duration of action and enzymatic stability under the conditions tested.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Gonadotropin-releasing hormone antagonists with N omega-triazolylornithine, -lysine, or -p-aminophenylalanine residues at positions 5 and 6. 128 Mar

A phosphonamide peptide, N-(phenylethylphosphonyl)-Gly-L-Pro-L-aminohexanoic acid, previously shown to block Clostridium histolyticum collagenases, was examined as a putative inhibitor of endopeptidase 24.16 and endopeptidase 24.15. Hydrolysis of two endopeptidase 24.16 substrates, i.e. 3-carboxy-7-methoxycoumarin (Mcc)-Pro-Leu-Gly-Pro-D-Lys-dinitrophenyl (Dnp) and neurotensin, were completely and dose-dependently inhibited by the phosphonamide inhibitor with KI values of 0.3 and 0.9 nM respectively. In addition, the phosphonamide peptide inhibited the hydrolysis of benzoyl (Bz)-Gly-Ala-Ala-Phe-(pAB) p-aminobenzoate and neurotensin by endopeptidase 24.15 with about a 10-fold lower potency (KI values of 5 and 7.5 nM respectively). The selectivity of this inhibitor towards several exo- and endo-peptidases belonging to the zinc-containing metallopeptidase family established that a 1 microM concentration of this inhibitor was unable to affect leucine aminopeptidase, carboxypeptidase A, angiotensin-converting enzyme and endopeptidase 24.11. The present paper therefore reports on the first hydrophilic highly potent endopeptidase 24.16 inhibitor and describes the most potent inhibitory agent directed towards endopeptidase 24.15 developed to date. These tools should allow one to assess the contribution of endopeptidase 24.16 and endopeptidase 24.15 to the physiological inactivation of neurotensin as well as other neuropeptides.
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PMID:Potent inhibition of endopeptidase 24.16 and endopeptidase 24.15 by the phosphonamide peptide N-(phenylethylphosphonyl)-Gly-L-Pro-L-aminohexanoic acid. 133 78

We examined the pattern and degree of the inflammatory process in bronchial biopsy specimens taken by fiberoptic bronchoscopy in eight asthmatic subjects (two women aged 19-38 years) after 5 years of specific immunotherapy (SIT) to mite extracts (SIT group). At the time of study, they received a maintenance dose of mite-extracts (last subcutaneous administration 3 weeks before bronchoscopy). Results were compared with those found in eight matched mite-sensitive subjects with stable asthma (two women aged 19-36 years; non-SIT group) and in eight healthy individuals (four women aged 22-29 years; control group). Bronchial biopsy specimens were fixed in periodate-lysine-paraformaldehyde, embedded in glycol methacrylate, and stained with hematoxylin-eosin and 2% toluidine blue. Number of eosinophils, mast cells, and total nucleated cells were counted separately in the epithelium and lamina propria by light microscopy and expressed as cells/high power field. Within the epithelium, eosinophil and mast cell counts in SIT and non-SIT groups were significantly higher compared to controls, whereas total cell counts were not statistically different. Within the lamina propria, total cell count in SIT and non-SIT groups was significantly higher compared with the control group, whereas mast cells were similar. The number of eosinophils in both SIT and non-SIT groups was higher compared with controls; however this reached statistical significance only in SIT-groups. Comparison between the two groups of asthmatics did not show any significant difference for any cell counts.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bronchial inflammation in mite-sensitive asthmatic subjects after 5 years of specific immunotherapy. 141 65

Calcitonin gene-related peptide (CGRP) is localized in and released from sensory nerves. It is a potent and long acting vasodilator which has been suggested to play a role in the control of blood flow. Using HPLC and trichloroacetic acid precipitation techniques, we have examined the ability of human mast cell lysates and a purified preparation of mast cell tryptase to degrade CGRP. We found that CGRP is effectively cleaved by tryptase (Km = 6.8 x 10(-6) mol/L at 37 degrees). Enzymatic activity was inhibited by antipain, leupeptin, N-alpha-p-tosyl-L-lysine chloromethyl ketone, benzamidine or aprotinin, but not by soybean trypsin inhibitor or N-tosyl-L-phenylalanine chloromethyl ketone. The degradation of CGRP by lysates of purified skin mast cells showed a similar pattern of inhibition suggesting that tryptase may be the major enzyme involved. The activity of tryptase was not affected by the presence of heparin. Incubation of CGRP with tryptase resulted in a loss of its vasodilator activity as observed by intravital microscopy of the hamster cheek pouch microvasculature. CGRP preincubated with tryptase failed to relax arterioles when added topically. It is suggested that the catalysis of CGRP by tryptase could represent an important means by which the activity of this neuropeptide is regulated in vivo.
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PMID:Human mast cell tryptase attenuates the vasodilator activity of calcitonin gene-related peptide. 156 77

The peptide hormones bradykinin and kallidin (Lys-bradykinin), as well as their analogues [des-Arg9]-bradykinin, a selective B1 agonist, [des-Arg9,Leu8]-bradykinin, a selective B1 antagonist, and [Thi5,8,D-Phe7]-bradykinin and D-Arg0-[Hyp3,D-Phe7]-bradykinin, two selective B2 antagonists, induced rapid histamine release from purified rat peritoneal mast cells. In contrast, the N-terminal fragment bradykinin-(1-5) was inactive. These peptides also activate the GTPase activity of GTP-binding proteins (G proteins) (Go/Gi) purified from calf brain, with an order of potency identical to that observed on mast cells, [Thi5,8,D-Phe7]-bradykinin much greater than kallidin greater than bradykinin greater than D-Arg0-[Hyp3,D-Phe7]-bradykinin greater than [des-Arg9]-bradykinin greater than [des-Arg9,Leu8]-bradykinin greater than bradykinin-(1-5). This correlation suggested that G proteins are the targets of kinins in mast cells. Accordingly, the concomitant increase in inositol trisphosphates and release of histamine elicited by kinins were inhibited by pertussis toxin pretreatment of mast cells. The inhibitory effect of benzalkonium chloride showed that the G proteins involved belong to the Gi type. GTPase activity was measured in the supernatant of homogenized mast cells but not in the membranous fraction. This activity was stimulated by kinins and by the venom peptide mastoparan. The potency of peptides was similar to that observed with purified bovine G proteins. Sodium dodecyl sulfate-gel electrophoresis of mast cell supernatant revealed pertussis toxin-induced ADP-ribosylation of two proteins, in the Mr 41,000 and 40,000 range, i.e., similar to purified alpha-subunits of Gi1 and Gi2 or Gi3 subtypes. The data support the proposal that bradykinin and analogues act like mastoparan, substance P, and compound 48/80, interacting first with sialic acid residues of the cell surface and then with Gi-like proteins, inducing phospholipase C activation and intracellular calcium mobilization.
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PMID:Activation of Gi-like proteins, a receptor-independent effect of kinins in mast cells. 170 Dec 14

Germline mutations at the Dominant White Spotting (W) and Steel (Sl) loci have provided conclusive genetic evidence that c-kit mediated signal transduction pathways are essential for normal mouse development. We have analysed the interactions of normal and mutant W/c-kit gene products with cytoplasmic signalling proteins, using transient c-kit expression assays in COS cells. In addition to the previously identified c-kit gene product (Kit+), a second normal Kit isoform (KitA+) containing an in-frame insertion, Gly-Asn-Asn-Lys, within the extracellular domain, was detected in murine mast cell cultures and mid-gestation placenta. Both Kit+ and KitA+ isoforms showed increased autophosphorylation and enhanced association with phosphatidylinositol (PI) 3' kinase and PLC gamma 1, when stimulated with recombinant soluble Steel factor. No association or increase in phosphorylation of GAP and two GAP-associated proteins, p62 and p190, was observed. The two isoforms had distinct activities in the absence of exogenous soluble Steel factor; Kit+, but not KitA+, showed constitutive tyrosine phosphorylation that was accompanied by a low constitutive level of association with PI-3' kinase and PLC gamma 1. Introduction of the point substitutions associated with W37 (Glu582----Lys) or W41 (Val831----Met) mutant alleles into c-kit expression constructs abolished (W37) or reduced (W41) the Steel factor-induced association of the Kit receptor with signalling proteins in a manner proportional to the overall severity of the corresponding W mutant phenotype. These data suggest a diversity of normal Kit signalling pathways and indicate that W mutant phenotypes result from primary defects in the Kit receptor that affect its interaction with cytoplasmic signalling proteins.
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PMID:Signal transduction by normal isoforms and W mutant variants of the Kit receptor tyrosine kinase. 171 77

A novel plasminogen-binding protein has been isolated from human plasma utilizing plasminogen-Sepharose affinity chromatography. This protein copurified with alpha 2 antiplasmin when the plasminogen affinity column was eluted with high concentrations of epsilon-aminocaproic acid (greater than 20 mM). Analysis by sodium dodecyl sulfate suggests this protein has an apparent Mr of 60,000. The amino-terminal amino acid sequence showed no similarity to other protein sequences. Based on the amino-terminal amino acid sequence, oligonucleotide probes were designed for polymerase chain reaction primers, and an approximately 1,800 base pair cDNA was isolated that encodes this Mr 60,000 protein. The deduced amino acid sequence reveals a primary translation product of 423 amino acids that is very similar to carboxypeptidase A and B and consists of a 22-amino acid signal peptide, a 92-amino acid activation peptide, and a 309-amino acid catalytic domain. This protein shows 44 and 40% similarity to rat procarboxypeptidase B and human mast cell procarboxypeptidase A, respectively. The residues critical for catalysis and zinc and substrate binding of carboxypeptidase A and B are conserved in the Mr 60,000 plasminogen-binding protein. The presence of aspartic acid at position 257 of the catalytic domain suggests that this protein is a basic carboxypeptidase. When activated by trypsin, it hydrolyzes carboxypeptidase B substrates, hippuryl-Arg and hippuryl-Lys, but not carboxypeptidase A substrates, and it is inhibited by the specific carboxypeptidase B inhibitor (DL-5-guanidinoethyl)mercaptosuccinic acid. We propose that the Mr 60,000 plasminogen-binding protein isolated here is a novel human plasma carboxypeptidase B and that it be designated pCPB.
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PMID:Isolation, molecular cloning, and partial characterization of a novel carboxypeptidase B from human plasma. 193 7

Rat mast cells purified on a Percoll gradient were challenged with compound 48/80 and protein kinase C activity in the cell pellets and the amount of histamine release into the supernatant was assayed by measuring the incorporation of 32P from [gamma 32P]ATP (adenosine triphosphate) into lysine-rich histone and by the fluorometric technique, respectively. In another series of experiments, rat mast cell granules were isolated in a gradient from sonicated rat mast cells and diphosphoinositide kinase activity was assayed by measuring the incorporation of 32P from [gamma 32P]ATP into triphosphoinositide on oxalic acid-impregnated silica gel plates after the extraction of lipids in acidic condition. Azelastine (A-5610, E-0659) inhibited the histamine release from the cells in parallel with the tendency to inhibit the increased protein kinase C activity in the activated mast cells. Azelastine also inhibited the diphosphoinositide kinase activity in the granules. These inhibitory effects of azelastine on the phosphorylation enzymes in rat mast cells may be involved in the inhibitory mechanism of the mediator release from the cells.
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PMID:Inhibitory effects of azelastine on protein kinase C and diphosphoinositide kinase in rat mast cells. 197 Jul 35

The neutral protease tryptase has been isolated from a human mast cell line, HMC-1. The HMC-1 line was established from the peripheral blood of a patient with mast cell leukemia and maintained as continuously proliferating clones in vitro and as solid mast cell tumors in nude mice. HMC-1-derived tryptase was purified by sequential chromatography on Dowex 1, DEAE 5 PW, and heparin-agarose. Purified tryptase has an apparent molecular weight of 150,000, as determined by molecular sieve HPLC, but migrates as a doublet of bands of 32/35,000 on SDS-PAGE gels. Maximal enzymatic activity was observed at pH 8.5. Cleavage of tosyl-L-arginine methyl ester by purified tryptase was inhibited by dansyl-L-glutamyl-glycyl-L-arginine chloromethyl ketone 2 HCl, HgCl2, tosyl-L-lysine chloromethyl ketone, leupeptin, and PMSF but not by benzamidine, aprotinin, tosyl-L-phenyl-alanine chloromethyl ketone, soybean trypsin inhibitor, human plasma, ovomucoid inhibitor, or lima bean trypsin inhibitor. Microsequencing of purified tryptase yielded an amino terminal sequence that was identical to that previously reported for human pituitary-derived tryptase.
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PMID:Purification of tryptase from a human mast cell line. 211 May 91

Human mast cells can be divided into two subsets based on serine proteinase composition: a subset that contains the serine proteinases tryptase and chymase (MCTC), and a subset that contains only tryptase (MCT). In this study we examined both types of mast cells for two additional proteinases, cathepsin G and elastase, which are the major serine proteinases of neutrophils. Because human mast cell chymase and cathepsin G are both chymotrypsin-like proteinases, the properties of these enzymes were further defined to confirm their distinctiveness. Comparison of their N-terminal sequences showed 30% nonidentity over the first 35 amino acids, and comparison of their amino acid compositions demonstrated a marked difference in their Arg/Lys ratios, which was approximately 1 for chymase and 10 for cathepsin G. Endoglycosidase F treatment increased the electrophoretic mobility of chymase on SDS gels, indicating significant N-linked carbohydrate on chymase; no effect was observed on cathepsin G. Immunoprecipitation and immunoblotting with specific antisera to each proteinase revealed little, if any, detectable cross-reactivity. Immunocytochemical studies showed selective labelling of MCTC type mast cells by cathepsin G antiserum in sections of human skin, lung, and bowel. No labeling of mast cells by elastase antiserum was detected in the same tissues, or in dispersed mast cells from lung and skin. A protein cross-reactive with cathepsin G was identified in extracts of human skin mast cells by immunoblot analysis. This protein had a slightly higher Mr (30,000) than the predominant form of neutrophil cathepsin G (Mr 28,000), and could not be separated from chymase (Mr 30,000) by SDS gel electrophoresis because of the size similarity. Using casein, a protein substrate hydrolyzed at comparable rates by chymase and cathepsin G, it was shown that about 30% of the caseinolytic activity in mast cell extracts was sensitive to inhibitors of cathepsin G that had no effect on chymase. Hydrolytic activity characteristic of elastase was not detected in these extracts. These studies indicate that human MCTC mast cells may contain two different chymotrypsin-like proteinases: chymase and a proteinase more closely related to cathepsin G, both of which are undetectable in MCT mast cells. Neutrophil elastase, on the other hand, was not detected in human mast cells by our procedures.
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PMID:Identification of a cathepsin G-like proteinase in the MCTC type of human mast cell. 221 56


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