Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An enkephalin-binding protein was found in human plasma and serum. The protein was partially purified by DEAE-cellulose column chromatography. The binding of [3H]leucine-enkephalin to this protein was competitively inhibited by unlabeled leucine- and methionine-enkephalin and various peptide hormones such as beta-endorphin and glucagon, but not by Leu-enkephalin-amide. The fact that amide derivatives of leucine-enkephalin and methionine-enkephalin did not inhibit the binding suggests that c-terminuses of enkephalins might have an important part in binding the protein. From these results, physiological roles of the enkephalin-binding protein are discussed.
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PMID:Enkephalin-binding protein in human blood. 281 10

N alpha-Acetyltransferase, which catalyzes the transfer of an acetyl group from acetyl coenzyme A to the alpha-NH2 group of proteins and peptides, was isolated from Saccharomyces cerevisiae and demonstrated by protein sequence analysis to be NH2-terminally blocked. The enzyme was purified 4,600-fold to apparent homogeneity by successive purification steps using DEAE-Sepharose, hydroxylapatite, DE52 cellulose, and Affi-Gel blue. The Mr of the native enzyme was estimated to be 180,000 +/- 10,000 by gel filtration chromatography, and the Mr of each subunit was estimated to be 95,000 +/- 2,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme has a pH optimum near 9.0, and its pI is 4.3 as determined by chromatofocusing on Mono-P. The enzyme catalyzed the transfer of an acetyl group to various synthetic peptides, including human adrenocorticotropic hormone (ACTH) (1-24) and its [Phe2] analogue, yeast alcohol dehydrogenase I (1-24), yeast alcohol dehydrogenase II (1-24), and human superoxide dismutase (1-24). These peptides contain either Ser or Ala as NH2-terminal residues which together with Met are the most commonly acetylated NH2-terminal residues (Persson, B., Flinta, C., von Heijne, G., and Jornvall, H. (1985) Eur. J. Biochem. 152, 523-527). Yeast enolase, containing a free NH2-terminal Ala residue, is known not to be N alpha-acetylated in vivo (Chin, C. C. Q., Brewer, J. M., and Wold, F. (1981) J. Biol. Chem. 256, 1377-1384), and enolase (1-24), a synthetic peptide mimicking the protein's NH2 terminus, was not acetylated in vitro by yeast acetyltransferase. The enzyme did not catalyze the N alpha-acetylation of other synthetic peptides including ACTH(11-24), ACTH(7-38), ACTH(18-39), human beta-endorphin, yeast superoxide dismutase (1-24). Each of these peptides has an NH2-terminal residue which is rarely acetylated in proteins (Lys, Phe, Arg, Tyr, Val, respectively). Among a series of divalent cations, Cu2+ and Zn2+ were demonstrated to be the most potent inhibitors. The enzyme was inactivated by chemical modification with diethyl pyrocarbonate and N-bromosuccinimide.
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PMID:Purification and characterization of an N alpha-acetyltransferase from Saccharomyces cerevisiae. 284 92

A human brain aminopeptidase, which hydrolyses low molecular weight enkephalin-containing peptides (ECPs), was purified to apparent homogeneity from the homogenate of human brain. The enzyme purification involved DEAE-cellulose chromatography and preparative polyacrylamide gel electrophoresis. The purified aminopeptidase hydrolyses only the Tyr1-Gly2 bond of enkephalines and of ECPs. The rate of hydrolysis of Met-enkephalin and Leu-enkephalin was higher than the rate of hydrolysis of ECPs containing 7 to 13 aminoacid residues. Large ECPs such as peptide E and beta-endorphin were not hydrolysed. The molecular weight of this enzyme is about 100,000 daltons, as determined by gel filtration on Sephadex G-200 and by polyacrylamide gel electrophoresis in presence of sodium dodecyl sulfate. The enzyme has an isoelectric point of pH 4.9, is activated by dithiothreitol (DTT) and inhibited by puromycin, bacitracin, p-mercuryacetate, Zn++, Cu++ and Ni++. The optimum pH for enzyme activity is 7.5.
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PMID:Isolation and characterization of human brain aminopeptidase which hydrolysis enkephalin-containing peptides. 318 70

Previous work from this laboratory described an association, based on genetic evidence, between a 68 000 dalton protein (p68) and corticotropin (ACTH) sensitive adenylate cyclase activity among variants of the Y1 mouse adrenocortical tumor cell line. To study the nature of this association further, we have purified p68 and raised a polyclonal anti-p68 serum in rabbits. A variant subclone of the Y1 line, in which p68 comprised approximately 10% of total soluble protein, was used as starting material. Purification of p68 was achieved by passage of a 100 000 X g supernatant fraction over DEAE-cellulose, fractionation with ammonium sulfate, and chromatography on hydroxylapatite. The purified protein had an isoelectric point of 7.3, a polarity value of 46%, and a blocked amino terminal end group. A rabbit antiserum raised against the purified p68 had a titer of 1:16 000 and specifically precipitated p68 from extracts of Y1 cells labeled with L-[35S]methionine. Using this antiserum, p68 also was detected in other cell lines including mouse erythroleukemia and Sertoli cells; rat Leydig, ovary, and glioma cells; and Chinese hamster ovary cells. The presence of p68 in a variety of cell types suggests that the function of p68 is not restricted to adrenal cells or to specific actions of ACTH.
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PMID:A 68 000 dalton protein genetically associated with corticotropin-sensitive adenylate cyclase activity. Purification and preliminary characterization using a specific antiserum. 608 78

Confluent 3T3-L1 fibroblasts incubated for 72 h with methylisobutylxanthine, dexamethasone, and insulin differentiate and acquire phenotypic characteristics of mature adipocytes, including hormone-sensitive cAMP phosphodiesterase activity located in a particulate fraction of homogenates. About 10 days after initiating differentiation, a maximally effective concentration of insulin (100 pM) increased particulate cAMP phosphodiesterase activity 40 to 60% in 8 min; activation persisted for at least 30 min in the presence of insulin. Incubation of adipocytes for 6-8 min with agents that increased cAMP, e.g. 1 microM epinephrine, 0.1 microM isoproterenol, corticotropin (2 mu units/ml), or thyroid-stimulating hormone (15 ng/ml), also increased particulate phosphodiesterase activity 40-60%. Changes in phosphodiesterase activity produced by epinephrine tended to lag behind changes in cAMP. Insulin, epinephrine, and corticotropin increased Vmax, not Km (0.5 microM), for cAMP. Particulate phosphodiesterase activity, solubilized with detergent, eluted in a single peak from DEAE-Bio-Gel. Insulin and epinephrine increased the activity eluted in this peak. Neither insulin nor lipolytic hormones increased activity in soluble fractions from differentiated cells or particulate or soluble fractions from undifferentiated cells. Incubation of adipocytes for 48 h with 1 microM dexamethasone prevented insulin-induced activation of the particulate phosphodiesterase and did not alter basal activity. After incubation for 72 h with 0.1 microM dexamethasone, insulin and epinephrine activation were abolished. These effects of dexamethasone on hormonal regulation of particulate phosphodiesterase activity could account for some of the so-called permissive effects of glucocorticoids on cAMP-mediated processes as well as the "anti-insulin" effects of glucocorticoids.
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PMID:Hormone-sensitive particulate cAMP phosphodiesterase activity in 3T3-L1 adipocytes. Regulation of responsiveness by dexamethasone. 619 Aug 11

A membrane-bound aminopeptidase was purified from rat brain, and its activity was assayed by high-pressure liquid chromatography with Met-enkephalin as the substrate. The enzyme was extracted with 1% Triton X-100 and purified by chromatography, successively on DEAE-Sepharose CL-6B, Bio-Gel HTP, and Sephadex G-200 columns. The overall purification was about 1200-fold, with 25% yield. The purified enzyme showed one band on disc gel electrophoresis and two bands on sodium dodecyl sulfate electrophoresis with molecular weights of 62 000 and 66 000. The aminopeptidase has a pH optimum of 7.0, a Km of 0.28 mM, and a Vmax of 45 mumol (mg of protein)-1 min-1 for Met-enkephalin. It releases tyrosine from Met-enkephalin, but it does not split the byproduct. It does not hydrolyze gamma- or beta-endorphin, or dynorphin, but it does hydrolyze neutral and basic aminoacyl beta-naphthylamides. The enzyme is inhibited by the aminopeptidase inhibitors amastatin, bestatin, and bestatin-Gly. Its properties, such as its subcellular localization, substrate specificity, pH optimum, and molecular weight, distinguish it from leucine aminopeptidase, aminopeptidase A, aminopeptidase B, aminopeptidase M, and the soluble aminopeptidase for enkephalin degradation.
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PMID:Purification and characterization of an enkephalin aminopeptidase from rat brain membranes. 683 39

A new melanocyte-stimulating peptide has been isolated from acid extracts of frozen human pituitary glands by salt/ethanol fractionation, Sephadex G-75 gel filtration and DEAE- and cM-cellulose ion-exchange chromatography. The peptide is glycosylated, has an N-terminal tryptophan residue and an apparent mol.wt. of 16000 as estimated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Its amino acid analysis closely resembles residues Trp-105 to Gln-29 predicted for the common precursor protein of bovine corticotropin and beta-lipotropin by Nakanishi, Inoue, Kita, Nakamura, Chang, Cohen & Numa [(1979) Nature (London) 278, 423-427]. This fragment is expected to have melanotropin activity due to the tetrapeptide -His-Phe-Arg-Trp- (residues -51 to -48) of the predicted sequence of the common precursor. It was found to have a molar potency of 1 X 10(-5) relative to alpha-melanotropin in the frog skin bioassay. These characteristics are consistent with the isolated melanotropin peptide being a non-corticotropin, non-lipotropin peptide of the human common precursor protein of corticotropin and lipotropin. The peptide neither potentiates the adrenal weight-maintenance activity of corticotropin-(1-24)-tetracosapeptide when administered to hypophysectomized rats, nor stimulates release of non-esterified fatty acids from isolated rat epididymal cells. A second N-terminal-tryptophan glycopeptide was also isolated, which had an amino-acid composition similar to that predicted for the bovine common precursor protein, residues Trp-105 to Gly-35.
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PMID:Purification and characterization of a gamma-melanotropin precursor from frozen human pituitary glands. 747 89

In previous reports we have demonstrated the presence of a soluble factor that responds to cAMP signals to induce steroid synthesis in adrenocortical tissue. Here, we describe the purification of this factor from adrenal zona fasciculata cells by using a five-step procedure that includes DEAE-cellulose, gel filtration, Mono Q HPLC and Superose HPLC, and elution of the protein from SDS/PAGE. This procedure results in the purification to homogeneity of a protein of 43-kDa that retains the capacity to stimulate steroid synthesis in an in vitro recombination assay. This activity is inhibited by the use of phospholipase A2 inhibitors. Antipeptide antibodies against the N-terminal region recognize p43 as a double band on SDS/PAGE that resolves in different spots on two-dimensional gel electrophoresis. Adrenocorticotropin treatment of adrenal glands results in the appearance of multiple spots that migrated towards a lower pH compared to controls, suggesting the presence of phosphorylated and dephosphorylated forms of p43. Sequencing of the N-terminal region and internal peptides reveals no significant similarities with other proteins, suggesting that p43 is a novel protein. We conclude from our data that the isolated protein (p43) is a novel, soluble protein that acts as intermediary in adrenocorticotropin-induced stimulation of arachidonic acid release and steroid synthesis.
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PMID:Purification of a novel 43-kDa protein (p43) intermediary in the activation of steroidogenesis from rat adrenal gland. 792 88

The objectives of this study were to develop an assay for the direct measure of porcine corticosteroid-binding globulin (pCBG) and to confirm age-related changes in plasma pCBG concentration. Isolation and purification of pCBG from plasma was performed by affinity chromatography and HPLC-DEAE anion exchange techniques. Analysis by SDS-PAGE revealed two polypeptides (54 and 59 kDa) having similar amino acid homology (>50%) to previously reported sequences of seven mammalian species for the first 33 amino acids. Porcine CBG (20 ng/well) was immobilized to microtiter plates and standards or samples added along with rabbit antiserum developed against the purified pCBG. Goat anti-rabbit IgG-alkaline phosphatase conjugate was added followed by p-NPP substrate. The resultant color development was read at 405 nm. Intra- and interassay coefficients of variation (n=26) of a pooled sample were 10 and 15%, respectively. Age-related changes (P<0.001) in plasma pCBG concentration (n=203) from day 3 through 168 of age confirmed that, in the pig, changes seen in the percent distribution of cortisol among protein bound and free forms around day 28 of age are associated with an increase in CBG concentration.
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PMID:Age-related changes in porcine corticosteroid-binding globulin (pCBG) as determined by an enzyme-linked immunosorbent assay. 1274 50

Biochemical properties of a termostable alkaline phosphatase obtained from the mycelium extract of A. caespitosus were described. The enzyme was purified 42-fold with 32% recovery by DEAE-cellulose and concanavalin A-Sepharose chromatography. The molar mass estimated by Sephacryl S-200 or by 7% SDS-PAGE was 138 kDa and 71 kDa, respectively, indicating a homodimer. Temperature and pH optima were 80 degrees C and pH 9.0. This enzyme was highly glycosylated (approximately 74% saccharide content). The activity was enhanced by Mg2+ (19-139%), NH4+ (64%), Na+ (51%) and Mn2+ (38%). 4-Nitrophenyl phosphate (4-NPP) was preferentially hydrolyzed, but glucose 1-phosphate (93%), UTP (67%) and O-phosphoamino acids also acted as substrates. V(lim) and K(m) were 3.78 nkat per mg protein and 270 micromol/L in the absence of Mg2+ and 7.35 nkat per mg protein and 410 micromol/L in the presence of Mg2+, using 4-NPP as substrate. The purified alkaline phosphatase removed the 5'-phosphate group of a linearized plasmid without showing DNAase activity, indicating its potential for recombinant DNA technology.
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PMID:Purification and biochemical characterization of a mycelial alkaline phosphatase without DNAase activity produced by Aspergillus caespitosus. 1770 60


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