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)

The secretory granules of rat serosal mast cells are able efficiently to degrade the apolipoprotein B component of low density lipoproteins (LDL) Kokkonen, J. O., and Kovanen, P. T. (1985) J. Biol. Chem. 260, 14756-14763). The granules are known to contain two neutral proteases with complementary specificities: a chymotrypsin-like endopeptidase called chymase, and an exopeptidase, the granule carboxypeptidase A. The role of this enzyme pair in the proteolytic degradation of LDL was studied with the aid of specific enzyme inhibitors. Incubation of LDL with intact granules (both enzymes active) led to the formation of numerous low molecular weight peptides and the liberation of free amino acids, most of which (95%) were aromatic (Phe, Tyr, Trp) or branched-chain aliphatic (Leu, Ile, Val). Selective inhibition of granule carboxypeptidase A (leaving chymase active) blocked the liberation of free amino acids, but left the formation of peptides uninhibited. On the other hand, selective inhibition of granule chymase (leaving carboxypeptidase A active) totally abolished the proteolytic degradation of LDL. The results are consistent with a model according to which the proteolytic degradation of LDL by mast cell granules results from coordinated action of the two granule-bound enzymes, whereby the chymase first cleaves peptides from the apolipoprotein B of LDL, and thereafter the carboxypeptidase A cleaves amino acids from the peptides formed.
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PMID:Low density lipoprotein degradation by secretory granules of rat mast cells. Sequential degradation of apolipoprotein B by granule chymase and carboxypeptidase A. 353 21

Pigeon liver malic enzyme was found to have arginine, alanine, and tyrosine as the only N-terminal, N-1, and N-2 amino acids, respectively. Hydrolysis of the reduced and carboxymethylated malic enzyme by carboxypeptidase A yielded quantitative evidence for the following C-terminal sequence: -Leu-(Phe-Ala)-Ile-Leu-COOH. Fifty-five trypsin-digested peptides were separated by HPLC, in accordance with the arginine and lysine contents of each subunit. This more direct structural evidence strongly supports the conclusion that pigeon liver malic enzyme is composed of four chemically identical subunits.
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PMID:Structural identity of the subunits of pigeon liver malic enzyme. 367 71

Fumarases in the mitochondrial and cytosolic fractions of rat liver were separately purified and crystallized. These two fumarases were not distinguishable in physicochemical, catalytic, or immunochemical properties. The sequences of seven amino acids in the C-terminal portions of the two fumarases were shown using carboxypeptidase P to be identical, i.e.-Val-Asp-Glu-Thr-Ala-Leu-Lys-. The amino acid sequence of the N-terminal portion of the mitochondrial fumarase was determined by the Edman method as Ala-Gln-Gln-Asn-Phe-Glu-Ile-Pro-Asp-, but that of the cytosolic fumarase could not be determined by the Edman method, since the N-terminal amino acid was blocked. The N-terminal amino acid of the cytosolic fumarase was identified as N-acetyl-alanine by analysis of the acidic amino acid produced by digestion of the enzyme protein with pronase E, carboxypeptidase A and B. Then the sequence of five amino acids in the N-terminal portion was determined by analyzing the acidic peptide obtained by limited proteolysis of the enzyme protein with carboxypeptidase A as Ac-Ala-Ser-Gln-Asn-Ser-. Peptide mapping of the tryptic peptides obtained from the mitochondrial and cytosolic fumarases showed no difference in the amino acid sequences of the two except in their N-terminal portions. The turnover rates of the mitochondrial and cytosolic fumarases were determined by injecting L-[U-14C]leucine into rat and following the decay of specific radioactivity incorporated into immunoprecipitates from the partially purified enzyme. The half-life of the cytosolic fumarase was estimated as 4.8 days from the decay curve of its specific radioactivity. The decay curve of the specific radioactivity of the mitochondrial fumarase, obtained after a single injection of L-[U-14]leucine, was quite unusual: its specific radioactivity remained constant for about 7 days after pulse labeling, and then decreased exponentially with a half-life of 9.7 days. Similar amounts of cytosolic and mitochondrial fumarase were found in the livers of the rat, mouse, rabbit, dog, chicken, snake, frog, and carp, respectively. Similar subcellular distributions of the enzyme were also found in the kidney, heart, and skeletal muscle of rats, and in hepatoma cells (AH-109A). However, in rat brain no fumarase activity was detected in the cytosolic fraction. Two putative precursor polypeptides of rat liver fumarase were synthesized when rat liver RNA was translated in vitro in a rabbit reticulocyte lysate system.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Mechanism of synthesis and localization of mitochondrial and cytosolic fumarases in rat liver. 381 85

The neutral histidine-rich polypeptide (HRP) from human parotid secretion was isolated by ion-exchange and gel-filtration chromatography. The complete amino acid sequence determined by automated Edman degradation of the protein, tryptic and Staphylococcus aureus V8 protease peptides, and digestion with carboxypeptidase A is: (Formula: see text) where Pse represents phosphoserine. The polypeptide contains 38 residues and has Mr 4929. The charged amino acids predominate with 7 histidine, 4 arginine, 3 lysine, 3 aspartic acid, 3 glutamic acid residues, and 1 phosphoserine. Assuming minimal charge contributions from histidine and one negative charge from phosphoserine at pH 7, the net charge of HRP is balanced by an equal contribution of basic and acidic residues. Furthermore, the distribution of hydrophilic and hydrophobic residues along the polypeptide chain indicates that there is no structural polarity. The polypeptide lacks threonine, alanine, valine, cysteine, methionine, and isoleucine. HRP did not display sequence similarity with any protein sequence in the National Biomedical Research Foundation Data Bank. HRP is an active inhibitor of hydroxyapatite crystal growth from solutions supersaturated with respect to calcium phosphate salts and therefore must play a role in the stabilization of mineral-solute interactions in oral fluid. In addition, HRP is a potent inhibitor of Candida albicans germination and therefore may be a significant component of the antimicrobial host defense system in the oral cavity.
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PMID:The primary structure and functional characterization of the neutral histidine-rich polypeptide from human parotid secretion. 394 83

1. On exhaustive digestion of carboxymethylated actin in 6m-urea solutions with carboxypeptidase A, 1 mole of phenylalanine was liberated/43000g. of protein. At a lower urea concentration and in the absence of urea, carboxymethyl-cysteine (CMCys) was also liberated. 2. Three cysteine-containing peptides were identified by the study of peptide ;maps' of tryptic digests of actin treated with thiol reagents. 3. The three peptides, each containing one residue of CMCys, were isolated from tryptic digests of carboxymethylated actin by ion-exchange chromatography. 4. One of these peptides was possibly the N-terminal peptide and contained about 17-18 residues; another was CMCys-Asp-Ile-Asp-Ile-Arg; the other, CMCys-Phe, was the C-terminal tryptic peptide. 5. The chemical evidence suggests that the actin molecule consists of a single polypeptide chain of molecular weight about 44000.
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PMID:Chemical studies on the cysteine and terminal peptides in tryptic digests of actin. 572 98

The mast cell degranulating capacity of neurotensin and three of its fragments was examined. In Tyrode solution (137 mM NaCl, 2.7 mM KCl, 0.4 mM NaH2PO4, 1.4 mM CaCl2, 1 mM MgCl2, 10 mM Hepes, 5.6 mM glucose, pH 7.4), neither intact neurotensin nor its C-terminal tripeptide (Tyr-Ile-Leu) caused any release of histamine. Concentrations of neurotensin exceeding 10(-4)M did cause histamine release but through lysis of the cells. The C-terminal hexa- and octapeptides of neurotensin (Arg-Arg-Pro-Tyr-Ile-Leu and Lys-Pro-Arg-Arg-Pro-Tyr-Ile-Leu, respectively) induced a non-cytolytic release of histamine with the latter peptide being more active (ED50 = 90 microM for the hexapeptide and 13 microM for the octapeptide). This release was not affected by the C-terminal tripeptide. It was found to be calcium-dependent and was inhibited by the anti-allergic drug, disodium cromoglycate. Phosphatidylserine did not enhance release of histamine and saturation of the immunoglobulin E (IgE) receptors did not inhibit it.
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PMID:Structure-activity relationship in the mast cell degranulating capacity of neurotensin fragments. 618 72

Two peptides rich in hydrophobic amino acids have been isolated from venom sacs of the European hornet, Vespa crabro. One peptide (P-2) is structurally and functionally related to the tetradecapeptide mastoparan and has been named mastoparan C. Leu-Asn-Leu-Lys-Ala-Leu-Leu-Ala-Val-Ala-Lys-Lys-Ile-LeuNH2. The other (P-1) is a tridecapeptide with a new sequence: Phe-Leu-Pro-Leu-Ile-Leu-Arg-Lys-Ile-Val-Thr-Ala-LeuNH2 which we have named crabrolin. The peptide releases histamine from rat peritoneal mast cells with a threshold of approximately 2.5 micrograms/ml (congruent to 8 microM). Crabrolin also facilitates the action of purified phospholipase A2 from different sources, but it is not quite as active as mastoparan. It is clearly less active than mastoparan in lysing erythrocytes, and it does not release amylase from dispersed guinea pig pancreatic acini. Given its unique sequence, the principal effect of crabrolin may be neither mast cell degranulation nor phospholipase facilitation, but a yet undiscovered action.
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PMID:Isolation and characterization of two new peptides, mastoparan C and crabrolin, from the venom of the European hornet, Vespa crabro. 620 53

Polymorphonuclear leukocytes have been shown to contain proteolytic enzymes which are capable of degrading connective tissue proteins such as native collagen. In this study, proteolytic enzymes were extracted from human polymorphonuclear leukocytes and a neutral proteinase was extensively purified and characterized. The activity of this enzyme was monitored by degradation of denatured [ 3H ]proline-labeled type I collagen or by cleavage of a synthetic dinitrophenylated peptide with a Gly-Ile sequence. The enzyme was readily separated from leukocyte collagenase by concanavalin-A--Sepharose affinity chromatography and further purified by QAE-Sephadex ion-exchange chromatography and gel filtration on Sephacryl S-200. The purified enzyme had a molecular weight of approximately 105000, its pH optimum was about 7.8, and it was inhibited by Na2EDTA and dithiothreitol, but not by fetal calf serum. The enzyme degraded genetically distinct type I, II, III, IV and V collagens, when in a non-helical form, but not when in native triple-helical conformation. Dansyl-monitored end-group analyses, combined with digestion by carboxypeptidase A, indicated that the enzyme cleaved denaturated type I collagen at Gly-Xaa sequences, in which Xaa can be leucine, isoleucine, valine, phenylalanine, lysine, or methionine. Thus, the purified enzyme referred to here as Gly-Xaa proteinase, is a neutral proteinase, which may be of importance in inflammatory disease processes by degrading further collagen peptides which have been rendered non-helical as a result of collagenase cleavage.
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PMID:Proteinases in human polymorphonuclear leukocytes. Purification and characterization of an enzyme which cleaves denatured collagen and a synthetic peptide with a Gly-Ile sequence. 634 59

Reexamination of the molecular mass and the amino acid composition of Serratia protease revealed the presence of 1 mol of methionine per mol of protein (about 46K daltons), and this was confirmed by BrCN cleavage followed by separation of the two fragments. The sole methionine residue was located near the middle region of the molecule. The amino(N)-terminal sequence was determined by Edman degradation of the protein and studies of several proteolytic peptides, establishing a sequence of 18 residues with a heterogeneous N-terminus. The carboxyl(C)-terminal sequence was determined by carboxypeptidase A digestion and tritium-labeling of the citraconylated C-terminal half segment to be -Phe-Ile-Val. The sequences of a total of 53 residues containing the methionine residue and a total of 38 residues containing two histidine residues were established by the application of various conventional methods to a BrCN peptide and several proteolytic peptides. The segment containing the histidine residues was homologous with that containing the two histidine residues chelating the zinc atom of thermolysin. The 38-residue segment may be directly connected to the 53-residue segment.
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PMID:Serratia protease. Amino acid sequences of both termini, the 53 residues in the middle region containing the sole methionine residue, and a probable zinc-binding region. 639 98

Multiple forms of urotensin II (UII), one of the hormonal peptides of the caudal neurosecretory system of fishes, were purified from the urophyses of the carp, Cyprinus carpio. Three distinct peaks with UII activity (classified as UII-alpha, -beta and -gamma) were separated by reverse-phase high-pressure liquid chromatography (HPLC). Edman degradation as well as digestion with carboxypeptidase A revealed the primary structures of these peptides as UII-alpha: Gly-Gly-Gly-Ala-Asp-Cys-Phe-Trp-Lys-Tyr-Cys-Val UII-beta: Gly-Gly-Ser-Asn-Thr-Glu-Cys-Phe-Trp-Lys-Tyr-Cys-Val UII-gamma: Gly-Gly-Gly-Ala-Asp-Cys-Phe-Trp-Lys-Tyr-Cys-Ile The results of thin-layer chromatography, HPLC, amino acid analysis, and sequencing indicate that UII-alpha and -gamma are homogeneous. UII-beta appears, however, to be a mixture of two components, differing only at position 2. Thus, in the carp urophysis, four forms of UII appear to be present, although the separation of two components in UII-beta has not been obtained. Sequence of positions 6-11 is common to all forms of UII isolated from the carp, sucker (Catostomus commersoni) and goby (Gillichthys mirabilis).
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PMID:Primary structures of multiple forms of urotensin II in the urophysis of the carp, Cyprinus carpio. 674 27


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