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)

1. Different lipoprotein density fractions from pig serum were isolated by phosphotungstate precipitation followed by purification in the preparative ultra-centrifuge. 2. The protein part of very low density lipoproteins was composed of approximately 52 percent lipoprotein B apoprotein and the rest of lipoprotein C II apoprotein and other as yet unidentified peptides. 3. The protein moiety of low density lipoproteins consisted primarily of lipoprotein B apoprotein (over 95 percent); the amino acid compositions of lipoprotein B apoprotein of very low and low density lipoproteins were practically identical. 4. The predominant polypeptide of pig serum high density lipoproteins exhibited an amino acid composition and a molecular weight very similar to human liprotein A I apoprotein. In contrast to human lipoprotein A I apoprotein, the apoprotein from pigs was found to release leucine first followed by alanine, threonine, and lysine upon incubation with carboxypeptidase A. 5. In pig serum the major lipoprotein C apoprotein was found to be a polypeptide similar in amino acid composition to lipoprotein C II apoprotein from human serum. The molecular weight of this polypeptide is approximately 8000. Incubation experiments with carboxypeptidase A indicate serine to be the most likely C-terminal amino acid.
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PMID:Studies on the composition of pig serum lipoproteins. Isolation and characterization of different apoproteins. 16 86

Angiotensin-converting enzyme has been solubilized from a particulate fraction of rabbit lung and purified to apparent homogeneity in 11% yield by a procedure including fractionation with DEAE-cellulose and calcium phosphate gel, elution from Sephadex G-200, and lectin affinity chromatography. The molecular weight estimated by equilibrium sedimentation was approximately 129,000, either in the absence or presence of 6 M guanidine hydrochloride. A slightly higher value of 140,000 determined for the reduced, denatured protein by gel electrophoresis in the presence of sodium dodecyl sulfate and a much higher figure derived from gel filtration are probably due to the glycoprotein nature of the enzyme. Its oligosaccharide content accounted for 26% of the weight calculated from its amino acid and carbohydrate composition. The estimated content of sugar residues per mole was: galactose, 57; N-acetylglucosamine, 53; mannose, 43; N-acetylneuraminic acid, 19; and fucose, 4. Threonine and alanine were identified, respectively, as NH2-terminal and COOH-terminal residues by the dansylation procedure and by digestion with carboxypeptidase A. The enzyme was found to contain approximately 1 g atom of zinc per mol. Km values for hydrolysis of hippurylhistidylleucine and angiotensin I were 2.3 and 0.07 mM, and the corresponding turnover numbers were 15,430 and 792 mol/min/mol at 37 degrees. Bradykinin was also a substrate, and release of its COOH-terminal dipeptide, Phe-Arg, was catalyzed at a comparable rate to that of His-Leu from the COOH terminus of angiotensin I. Enzyme activity required the presence of chloride ions and was inhibited by EDTA and by low concentrations of Bothrops bradykinin-potentiating peptides. In addition, hydrolysis of hippurylhistidylleucine was inhibited competitively by other defined peptides, including di- and tripeptides, which were not substrates.
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PMID:Pulmonary angiotensin-converting enzyme. Structural and catalytic properties. 16 57

A ninhydrin-negative peptide fraction obtained from tryptic digest of carboxymethyl acylphosphatase was isolated by chromatography on a column of PA 28 Beckman resin and analysed for the amino acid composition. Degradation with carboxypeptidase B and A indicated that the sequence of this peptide was: X-Thr-Ala-Arg. The amino-terminal residue was identified as N-acetylserine by high voltage electrophoresis. It is therefore suggested that the sequence of the NH2-terminal portion of CM-acylphosphatase is N-acetyl-Ser-Thr-Ala-Arg. Digestion with carboxypeptidase A and B indicated also that the COOH-terminal portion of CM-acylphosphatase is-Arg-Tyr-OH.
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PMID:N-acetylserine in horse muscle acylphosphatase. 17 62

It had been reported by authors that salivary gland hormone, parotin, was composed with subunit (parotin-subunit) which showed molecular weight of 45,000, and that parotin-subunit had rabbit serum calcium decreasing activity and the cross reactivity with rabbit anti parotin serum. In the present report, in order to study physiological chemistry of parotin-subunit, the influence of parotin-subunit on serum Ca and 45Ca levels relating to calcium metabolism, the distribution of 131I-parotin-subunit, the effect of parotin-subunit, on adenyl cyclase-cyclicAMP system, the anabolic action, C-terminal amino acid sequence and sugar component of parotin-subunit were investigated. The results are summarized as follows: 1) The decrease of rabbit serum Ca after injection of parotin-subunit was related to change of Ca in stable bone, but not to inhibition of bone resorption. 2) A high concentrated localization of radioactivity of 131I-parotin-subunit was found in liver, kidney and spleen, and as much as 60% of administrated radioactivity was localized in liver at 5 min after the injection. The retention of radioactivity was found in testis, seminal vesicle, prostate, parotid gland and submaxillary gland. 3) Cyclic AMP level increased significantly in metaphysial bone, submaxillary gland and plasma after administration of parotin-subunit but in other organs with localized much radioactivities, the level did not changed. Parotin-subunit activated adenyl cyclase of particular fraction of metaphysial bone. 4) The C-terminal amino acid of parotin-subunit was Leu, and its C-terminal amino acid sequence was -Val-Ser-Ala-Thr- Leu-OH by digestion of carboxypeptidase A. 5) Parotin-subunit included 3.3% of sugar which consisted of amino sugar and uronic acid.
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PMID:[The study of physiological chemistry on a subunit of salivary gland hormone (2) (author's transl)]. 18 2

Baboon high-density lipoproteins (HDL) were isolated by preparative ultracentrifugation between d = 1.063 and 1.215 g/mL. The HDL contains 48.8% protein and a lipid distribution similar to human HDL. The phospholipid distribution shows a low sphingomyelin value (5.9%), and the fatty acid composition of HDL is comparable to the human data except for the 18:1/18:2 ratio as a result of a higher 18:1 content in the CE and a lower 18:2 concentration in the PL. The major HDL apoproteins isolated on diethylaminoethyl-cellulose had a mobility on sodium dodecyl sulfate--polyacrylamide gel electrophoresis and a molecular weight and an amino acid composition similar to human apoA-I. However, the amino acid sequence of the first 30 residues of baboon apoA-I differed from the human apoprotein in residues 15 and 21. Treatment of apoA-I with carboxypeptidase A indicated a carboxyl-terminal sequence of Leu-Ser-Thr-Gln. Baboon apoHDL contained monomeric apoA-II with the mobility of monomeric human apoA-II and a molecular weight of 8500. The amino acid composition differed from the human apoA-II by the presence of arginine and by the absence of half-cystine and isoleucine. The circular dichroic spectra of apoA-I and apoA-II demonstrated a higher helicity compared to the human apoproteins. Recombination studies by microcalorimetry of apoHDL with dimyristoylphosphatidylcholine (DMPC) indicated similarities in the thermodynamic binding properties of the HDL apoproteins from man and baboon. The maximal-binding enthalpies of DMPC to apoHDL, apoA-I, and apoA-II were lower for the baboon than for the human apoprotein.
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PMID:Characterization of baboon plasma high-density lipoproteins and of their major apoproteins. 19 55

Determination of the amino acid sequence of the immunogenic polypeptides of hepatitis B surface antigen may not only permit molecular localization of the distinct determinants a, d, and y but may also lead to the synthesis of a hapten useful in prophylactic immunization against hepatitis B virus infection. For this purpose, purified monotypic hepatitis B surface antigen of adw subtype was resolved into equal amounts of two major polypeptides (22,000 and 28,000 daltons) and up to six other minor polypeptides by polyacrylamide gel electrophoresis. With the periodate staining reaction, only the 28,000-dalton polypeptide stained as a glycoprotein. Guinea pigs immunized with the 22,000-dalton polypeptide produced potent antisera against determinants a and d, but the 28,000-dalton glycoprotein did not induce a response. Both polypeptides isolated by preparative polyacrylamide gel electrophoresis showed amino acid composition identical with that of the intact antigen. For both polypeptides, hydrazinolysis gave Ile as the carboxyterminus, and carboxypeptidase A digestion gave the same terminal sequence, Val-Tyr-Ile. Both peptides also yielded an identical sequence of amino acids in nine steps of Edman degradation--Met-Glu-Asn-Ile-Thr-Ser(Cys)-Gly-Phe-Leu. Our data suggest that hepatitis B surface antigen contains a single major immunogenic 22,000-dalton polypeptide component, part of which is modified by the addition of carbohydrate to give rise to the glycopeptide of apparent molecular weight 28,000.
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PMID:Partial amino acid sequence of two major component polypeptides of hepatitis B surface antigen. 26 93

The crystal structure of penicillopepsin, an extracellular acid protease isolated from the mold Penicillium janthinellum, has been determined at 2.8 A resolution by the method of multiple isomorphous replacement. The resulting electron density map computed from the native structure factor amplitudes and MIR phases has an overall mean figure of merit of 0.90. The molecule is decidedly nonspherical, with the majority of residues in beta-structure. There is an 18-stranded mixed beta-sheet which forms the structural core in the region of the active site. This site, identified by the covalent binding of two EPNP molecules to Asp-32 and Asp-215, is located in a deep groove which divides the molecule into two approximately equal lobes. Both aspartic acid residues in the active site are in intimate contact with one another and the carboxyl group of Asp-32 makes two other important hydrogen-bonded contacts: one with Ser-35 and the other with the main chain peptide bond between Thr-216 and Gly-217. A proposed mechanism for acid protease catalysis is similar in many aspects to that proposed for carboxypeptidase A. The electrophilic component which polarizes the substrate carbonyl bond in the acid proteases is the proton shared between the beta-carboxyl groups of Asp-32 and Asp-215. The beta-carboxyl group of Asp-32 removes a proton from a water molecule bound between this side chain and the substrate; the resultant OH- attacks the carbonyl carbon atom of the substrate molecule. The phenolic -OH group of Tyr-75 donates its proton to the amide nitrogen of the scissile bond of the substrate.
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PMID:Penicillopepsin: 2.8 A structure, active site conformation and mechanistic implications. 33 94

A rapid purification procedure for large scale preparations of yeast proteinase B inhibitors 1 and 2 (IB1 and IB2) is described. By disc gel electrophoresis, amino acid analysis, and end-group determinations, each of the inhibitors is homogeneous. Both inhibitors are polypeptides with molecular weights of 8,500, containing 74 residues. No components other than amino acids could be detected. There is no significant difference in the amino acid compositions of the two inhibitors as analyzed after acid hydrolysis. Both polypeptides are characterized by the total absence of arginine, tryptophan, and sulfur-containing amino acid residues. The proteinase B inhibitors of yeast, therefore, differ fundamentally from proteinase inhibitors of many other organisms, which generally contain a large number of disulfide bridges. Both proteinase B inhibitors have threonine as the NH2-terminal residue and -Val-His-Thr-Asn-COO- as the COOH-terminal sequence. Comparison of peptide maps after tryptic digestion reveals that the two inhibitors differ definitely in only a few tryptic peptides. The inhibitors are rapidly inactivated by digestion with carboxypeptidase A from bovine pancreas at pH 8.5. Inactivation occurs stoichiometrically with the release of threonine, the penultimate residue at the COOH-terminal end of both inhibitors.
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PMID:Purification and molecular characterization of two inhibitors of yeast proteinase B. 38 8

Eosinophil migration toward a concentration gradient of a chemotactic factor is regulated at four levels. Diverse immunologic pathways generate stimuli with eosinophil chemotactic activity, including the complement products C5a and a fragment of C3a and the peptide products of mast cells and basophils activated by IgE-mediated reactions, such as eosinophil chemotactic factor of anaphylaxis (ECF-A) and other oligopeptides. The intrinsic preferential leukocyte activity of the chemotactic stimuli represents the second level of modulation, with ECF-A and other mast cell-derived peptides exhibiting the most selective action on eosinophils. The third level of control of eosinophil chemotaxis is composed of inactivators and inhibitors of chemotactic stimuli and is exemplified by degradation of C5a by anaphylatoxin inactivator or chemotactic factor inactivator and of ECF-A by carboxypeptidase-A or aminopeptidases. The activity of ECF-A is uniquely suppressed by equimolar quantities of its NH2- terminal tripeptide substituent, presumably by eosinophil membrane receptor competition. Factors comprising the fourth level of regulation, which alter eosinophil responsiveness to chemotactic stimuli, include the chemotactic factors themselves, through deactivation; nonchemotactic inhibitors such as the COOH-terminal tripeptide substituent of ECF-A, the neutrophil-immobilizing factor (NIF), the phagocytosis-enhancing factor Thr-Lys-Pro-Arg, and histamine at concentrations greater than 400 ng/ml; and nonchemotactic enhancing principles represented by ascorbate and by histamine at concentrations of 30 ng/ml or less. Local concentrations of eosinophils called to and immobilized at the site of a hypersenitivity reaction may express their regulatory functions by degrading the chemical mediators elaborated including histamine, slow-reacting substance of anaphylaxis (SRS-A), and platelet-activating factor (PAF) by way of their content of histaminase, arylsulfatase B, and phospholipase D, respectively. Immunologic pathways may thus provide the capability for early and specific host defense reactions with a later influx of eosinophils preventing irreversible local tissue alterations or distant organ effects.
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PMID:Modulation of human eosinophil polymorphonuclear leukocyte migration and function. 79 10

Porcine C3a was generated in whole porcine serum by inulin activation of enzymes of the alternative complement pathway. The C3a anaphylatoxin was isolated according to the procedures previously described by Hugli. The complete amino acid sequence for porcine C3a was determined utilizing automatic sequencing techniques in addition to manual subtractive Edman degradation and carboxypeptidase A, B, or Y digestion of isolated peptides. Porcine C3a is composed of a polypeptide chain containing 77 amino acid residues and has a m.w. of approximately 9,000 daltons. This C3a molecule is devoid of threonine, tryptophan, and carbohydrates. The proposed primary structure for porcine C3a is as follows: (see article) Comparisons between the amino acid sequences of human and porcine C3a reveal that the six half-cystinyl and five aromatic residue positions are conserved. Conservation of these six half-cystinyl residue positions suggest that the disulfide arrangement remains identical in both anaphylatoxin molecules. Maintenance of three interconnected disulfide linkages helps to explain a near identity between the secondary structures of human and porcine C3a as indicated by circular dichroism measurements. Particular attention was focused on the COOH-terminal region of the anaphylatoxins since an arginyl residue at position 77 is functionally essential in both human and porcine C3a. Five residue positions at the carboxy termini were conserved in both C3a molecules, and the sequence Leu-Gly-Leu-Ala-Arg probably relates directly to anaphylatoxin activity. A total of 23 residue replacements occur between human and porcine C3a which accounts for a 30% difference in primary structure. Although the C3a molecules exhibit identical biologic activity, this rather large structural difference readily explains the absence of a detectable immunologic cross-reactivity.
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PMID:The primary structure of porcine C3a anaphylatoxin. 95 63


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