Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

A double antibody immunoprecipitation technique using affinity-purified adrenocorticotropic hormone (ACTH) antiserum was employed to investigate the biosynthesis of ACTH in a mouse pituitary tumor cell line. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of cell extracts resolved four forms of ACTH with apparent molecular weights of 4,500, 13,000, 23,000, and 31,000. These four forms of ACTH can be detected by radioimmunoassay of cell extracts or by immunoprecipitation of cell extracts following incubation of cultures in [3H] tryptophan, [3H] lysine, or [3H] tyrosine. The double antibody immunoprecipitation scheme developed is specific, quantitative, and reproducible. ACTH biosynthesis was examined in both steady and pulse-labeling experiments using [8H] tyrosine or [3H] lysine. The results of these experiments are consistent with the proposal that Mr=31,000 ACTH is the biosynthetic precursor for all three smaller forms of ACTH and that Mr=23,000 ACTH is a biosynthetic intermediate. Both Mr=13,000 ACTH and Mr=4,500 ACTH are derived from the intracellular processing of Mr=31,000 ACTH.
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PMID:Biosynthesis of adrenocorticotropic hormone in mouse pituitary tumor cells. 18 15

Double-antibody immunoprecipitation procedures with antisera to endorphins and to corticotropin (ACTH) were used to study the biosynthesis of these peptides in a mouse pituitary tumor cell line. Cultures were incubated with a (3)H-labeled amino acid, and aliquots of culture medium were immunoprecipitated. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis of [(3)H]phenylalanine-labeled immunoprecipitates prepared with endorphin antisera resolved three forms of endorphin with apparent molecular weights of 31,000, 11,700, and 3500; immunoprecipitates prepared with the ACTH antiserum contained four forms of ACTH with apparent molecular weights of 31,000, 23,000, 13,000 and <4500. Sequential immunoprecipitation of culture medium with the ACTH antiserum and then with the endorphin antiserum (or the reverse order) indicated that both antisera precipitated the same 31,000 dalton molecule. Purified pools of the different forms of ACTH and endorphin were prepared by immunoprecipitation and gel filtration. The tryptic peptides found in [(3)H]phenylalanine- or [(3)H]tryptophan-labeled 31,000 dalton ACTH were identical to the tryptic peptides found in digests of 31,000 dalton endorphin labeled with the same amino acid. A tryptic peptide similar to the lipotropin tryptic peptide [betaLPH(61-69)] that contains the opiate-active methionine-enkephalin sequence could be identified in 31,000 dalton ACTH and in all the different forms of endorphin. Most of the peptide cleaved from 31,000 dalton ACTH when it is converted to 23,000 dalton ACTH could be precipitated by endorphin antisera; this 11,700 dalton endorphin molecule is similar to the pituitary hormone betaLPH in size and structure. The 3500 dalton endorphin is similar to beta-endorphin in size and structure. The culture medium from the AtT-20 mouse pituitary tumor cells contained approximately equimolar amounts of ACTH-related peptides and endorphin-related peptides.
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PMID:Common precursor to corticotropins and endorphins. 19 29

The concentrations and molecular sizes of immunoreactive corticotropin (ACTH), lipotropin (LPH, beta LPH plus gamma LPH), gamma LPH, and beta-endorphin (beta END) were determined in human placental extracts. Serial dilutions of a water extract of placenta generated competitive binding curves parallel with that of the standard in each assay. The concentrations of ACTH, LPH, gamma LPH, and beta END were 3.3, 0.8, 0.7, and 1.1 ng/g wet weight of tissue, respectively. A partially purified extract applied to a Sephadex G-50 column contained high Mr components with ACTH, LPH, gamma LPH, and beta END immunoreactivities. The extract was applied to an immune affinity chromatography column consisting of affinity-purified (1-24)ACTH antiserum covalently bound to agarose. The material that adsorbed to the column and eluted with buffer containing sodium dodecyl sulfate had ACTH, LPH, and beta END immunoreactivities, indicating that there was a component or components containing antigenic determinants for all of these peptides. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis of the affinity-purified placental extract revealed at least two high Mr components (Mr approximately 48,000 and 36,000) with all three immunoreactivities. These data suggest, but do not prove, that the placenta synthesizes ACTH, the LPHs, and beta END from a common precursor molecule.
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PMID:Human placental immunoreactive corticotropin, lipotropin, and beta-endorphin: evidence for a common precursor. 22 12

We have previously shown that cultured bovine pituitary or hypothalamic cells incorporate 3H-labeled amino acids into high molecular weight glycoproteins containing the antigenic determinants of both corticotropin (ACTH) and beta-endorphin. We now report resolution of this 3H-labeled ACTH/beta-endorphin-like material into two predominant size classes upon SDS polyacrylamide-gel electrophoresis with apparent molecular weights (Mr) of 41 500 +/- 1600 and 36 000 +/- 1100. Isoelectric focusing revealed these components to be basic proteins with apparent isoelectric points greater than 8.5. Overnight trypsinization generated a 3H-labeled fragment comigrating with synthetic beta-lipotropin (61-69) [beta-endorphin (1-9)] upon paper electrophoresis which was immunoprecipitable with antibody directed against the corresponding synthetic fragment. Limited trypsinization of bovine immunoreactive ACTH/beta-endorphin extracted from freshly obtained bovine hypothalamic and anterior pituitary tissue, generated fragments which possessed ACTH bioreactivity. Both bovine pituitary and hypothalamic derived material are similar with respect to these foregoing physiochemical parameters and appear to be larger than the reported forms in mouse pituitary.
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PMID:Preliminary characterization of in vitro synthesized hypothalamic precursor ACTH/beta-endorphin-like material. 23 Jan 5

In this study we have compared the effects of different pro-opiomelanocortin (POMC) peptides on melanogenesis and metastasis and their relationship to MSH receptor expression in B16F1 melanoma cells. All peptides, apart from beta-endorphin, increased melanogenesis and the order of potency was Nle4DPhe7-alpha-MSH greater than alpha-MSH greater than ACTH[1-39] greater than des-acetyl alpha-MSH greater than ACTH[1-24]. A similar order of potency was found for metastasis, except for ACTH [1-24], which had a relatively greater effect on metastasis. These findings suggest that the effects on melanogenesis and metastasis are mediated via the same receptor. The results of ligand binding studies also indicated the presence of a single receptor with a KD value for Nle4DPhe7-alpha-MSH of 62 +/- 16pM. This was consistent with crosslinking studies using [125I] Nle4DPhe7-alpha-MSH which produced a single 50-55 kD band on analysis by SDS-PAGE. However, the relative binding affinities of the different peptides, measured by displacement of [125I]-Nle4DPhe7-alpha-MSH, did not closely correlate with the relative potencies in stimulating melanogenesis and metastasis. This suggests that receptor activation and the subsequent biological response is not determined solely by binding affinity.
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PMID:MSH receptor expression and the relationship to melanogenesis and metastatic activity in B16 melanoma. 132 55

The alpha-melanocyte-stimulating hormone (alpha-MSH) receptor of B16 mouse melanoma cells was characterized by photoaffinity labelling using radiolabelled photoactive derivatives of alpha-MSH. A doublet band of 43-46 kDa representing a ligand-receptor complex was identified. A novel adaptation of the streptovadin/biotin-based affinity system was used to isolate the alpha-MSH receptor. A probe was synthesized which contained biotin connected to a photolabelled alpha-MSH analogue via a cleavable disulphide linker and which displayed high affinity for the alpha-MSH receptor. Streptavidin-coated magnetic beads were used as a solid support instead of an affinity column. Covalently linked probe-receptor complexes solubilized in Triton X-100 were equilibrated with the beads, and after magnetic separation and washing, specifically bound complexes were treated with dithiothreitol to cleave the disulphide bridge in the biotin-peptide spacer arm and so release the receptor-ligand complex. The identity of the isolated protein was established by SDS/PAGE analysis. Methods to achieve purification to homogeneity and to allow quantitative isolation of the receptor are discussed.
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PMID:Isolation and partial purification of a melanocyte-stimulating hormone receptor from B16 murine melanoma cells. A novel approach using a cleavable biotinylated photoactivated ligand and streptavidin-coated magnetic beads. 132 40

In order to clarify the mechanism of substance P (SP)-induced cortisol secretion from bovine adrenocortical (BAC) cells, protein synthesis at the early stage of SP-stimulation in BAC cells was investigated. Both SP and adrenocorticotropic hormone (ACTH) increased [3H]leucine uptake into BAC cells in a dose-dependent fashion. Although the SP-induced [3H]leucine uptake precedes the cortisol secretion, ACTH was slower in inducing [3H]leucine uptake and cortisol secretion. Protein synthesis inhibitors, actinomycin D and cycloheximide, were potent in inhibiting the SP-induced cortisol secretion. SDS-PAGE analysis, revealed that a 240 kDa protein is newly synthesized in BAC cells in response to SP but not ACTH. It was also indicated that the production of this 240 kDa protein was elicited about 30 min after stimulation by SP. Moreover, A23187 and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) also caused a rapid [3H]leucine uptake and production of 240 kDa protein. In contrast, dibutyryl cAMP did not induce the synthesis of this 240 kDa protein. Calmidazolium, a calmodulin inhibitor, effectively inhibited not only [3H]leucine uptake but also 240 kDa protein production due to SP. On the other hand, KT-5720, an inhibitor of protein kinase A, had no effect on [3H]leucine uptake or 240 kDa production. Using the [125I]calmodulin-membrane overlay method, it was found that the 240 kDa protein was a newly synthesized calmodulin binding protein. From the present study, it was concluded that the de novo synthesis of this 240 kDa protein may be intimately related to the cortisol secretion in SP-stimulated BAC cells associated with an activation of the Ca-calmodulin pathway.
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PMID:de novo synthesis of calmodulin binding protein in substance P-induced steroidogenesis in bovine adrenocortical cells. 138

Cultured bovine adrenal fasciculata cells were used to characterize angiotensin II (A-II) and corticotropin (ACTH) receptors and to study their homologous and heterologous regulation. These cells contain one type of high affinity binding sites for A-II (KD congruent to 2.4 +/- 0.3 10(-9) M) and about 100000 sites/cell. Photoaffinity labeling followed by SDS-PAGE under reducing conditions revealed a single macromolecule of apparent MR 65,000. Treatment of cells with increasing concentrations of A-II produced down-regulation of its own receptors and marked homologous and heterologous (ACTH) steroidogenic desensitization. However, the desensitization was not correlated with receptor loss and was mainly due to alterations of the steroidogenic pathway. Pretreatment of cells with ACTH also reduced A-II receptors, but this was not associated with steroidogenic desensitization. Bovine fasciculata cells contain two binding sites for ACTH: one of high affinity (KD congruent to 2.6 +/- 0.4 10(-10) M) and low capacity (2030 +/- 390 sites/cell) and the other of low affinity and high capacity. Affinity cross-linking of ACTH to plasma membranes prepared from adrenal cells revealed a labeled macromolecule of apparent MR 43000. However, cross-linking experiments to intact cells revealed, both under reducing and non-reducing conditions, two labeled macromolecules of apparent MR of 123000 and 43000. Pretreatment of cells with ACTH enhanced its receptor and the cAMP and cortisol responses to further ACTH stimulation. These effects were time- and dose-dependent. The maximal effects were observed at 10(-10) to 10(-9) M. A-II alone had no effect but it blocked partially the stimulatory action of ACTH.
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PMID:Characterization and regulation of angiotensin and corticotropin receptors on cultured bovine adrenal cells. 165 29

The heterogeneity of melanotropin receptors on B16 sublines was tested by using photoaffinity crosslinking techniques and the superpotent alpha-MSH derivative [Nle4, D-Phe7, 1'-(2-nitro-4-azido-phenylsulfenyl)-Trp9]-alpha- MSH (NAPS-MSH). Specific crosslinking of this compound to B16-F1, B16-F10, B16-M2R or B16-W4 cells revealed three different subtypes of MSH receptor based on SDS-PAGE analysis. Binding of monoiodinated alpha-MSH to these different subclones is saturable and characteristic for a single class of complexes (0.9 nM less than KD less than 1.6 nM). In this article the nature of the different MSH receptor subtypes as well as their possible correlation to the melanogenic potential of a particular cell line is discussed.
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PMID:Heterogeneity of the MSH receptor among B16 murine melanoma subclones. 165 43

The processing of pro-opiomelanocortin (POMC) to ACTH- (adrenocorticotropin), MSH- (melanotropin) and endorphin-related peptides was studied in mouse embryos with the ultimate aim of determining the role of the POMC-related peptides in early development especially in the CNS. Mouse embryos at gestational days 10.5, 11.5, 12.5 and 14.5 were analyzed for POMC-derived peptides by SDS-PAGE, HPLC and radioimmunoassay using antisera specific for various regions of the prohormone. At embryonic day 10.5 (E 10.5) the prohormone was the major product detected. At E 11.5, POMC was processed to ACTH(1-39), des-acetyl alpha-MSH and beta-endorphin(1-31) and beta-endorphin(1-27). The amounts of these peptides increased at E 12.5, and at E 14.5. At E 14.5, there was a major increase in ACTH(1-39) and beta-endorphin(1-31) peptides. This was attributed to the large increase of corticotrophs in anterior pituitary at this stage. Des-acetyl alpha-MSH levels, however, were similar at E 12.5 and E 14.5 and the peptide was confined mainly to the central nervous system. gamma-MSH was not detected until E 16.5 in the brain. No alpha-MSH or acetylated beta-endorphin was detected between E 11.5 and E 14.5. Thus in early embryonic development, POMC is processed to des-acetyl alpha-MSH, beta-endorphin(1-31), beta-endorphin(1-27) and gamma-MSH in the brain, and primarily to ACTH(1-39) and beta-endorphin(1-31) in the anterior pituitary. Some differences exist in the forms of POMC-derived peptides found in embryonic versus adult brain and pituitary. The embryonic forms of the peptides may be significant in playing a role during development.
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PMID:Prenatal processing of pro-opiomelanocortin in the brain and pituitary of mouse embryos. 165 30


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