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)

Radioactive proteins synthesized in an mRNA-dependent reticulocyte cell-free system under the direction of mRNA from AtT-20/D-16v mouse cells were isolated by specific immunoprecipitation using antiserum to either alpha(1-24) corticotropin or beta-endorphin [beta(61-91) lipotropin]. Each immunoprecipitate was fractionated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and shown to contain only one labeled protein with an apparent molecular weight of 28,500. Tryptic peptide analysis of the Mr 28,500 corticotropin and beta-lipotropin molecules isolated from the gels demonstrated that the two proteins had the same lysine, methionine, and tryptophan peptides. Four tryptic peptides from the cell-free product exhibited the same electrophoretic and chromatographic mobilities as marker tryptic peptides from bovine beta-melanotropin and porcine beta-endorphin. The identification of these peptides was confirmed by amino acid composition studies with a variety of labeled amino acids. The beta-lipotropin tryptic peptides were also shown to be located carboxy terminal to the corticotropin tryptic peptides.
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PMID:Characterization of a common precursor to corticotropin and beta-lipotropin: identification of beta-lipotropin peptides and their arrangement relative to corticotropin in the precursor synthesized in a cell-free system. 20 48

Effect of methionine-, leucine-enkephalin (met-, leu-enkephalin) and substance P on the transmission in mouse vas deferens was studied. Both met- and leu-enkephalin inhibited electrically induced contraction of vas deferens at 10(-8)-10(7) M, met-enkephalin being 1.4 times more active than leu-enkephalin. Nalorphine (10(-6) M) antagonized these effects. Substance P (10(-9)-10(-7) M) had no effect on the contraction. Met- and leu-enkephalin (10(-7)-10(-5) M) decreased the high potassium induced [3H]-norepinephrine release from vas deferens, while substance P (10(-6) M) significantly increased it. Nalorphine (10(-5) M) reversed the inhibitory effect of met-enkephalin. These results indicate that these peptides modify the transmission of sympathetic nerve in mouse vas deferens.
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PMID:Effect of enkephalin and substance P on sympathetic nerve transmission in mouse vas deferens. 20 50

A structure-function study of alpha-melanotropin has shown that this tridecapeptide consists of two message sequences, (-Glu)-His-Phe-Arg-Trp- and -Gly-Lys-Pro-Val-NH2, and a potentiator sequence, Ac.Ser-Tyr-Ser-Met-(Glu-), when acting on its melanophore receptors. The key elements of the message, -Phe-Arg- and -Lys-Pro-, do not correspond exactly to those responsible for eliciting the effect in other tissues. It appears that alpha-MSH contains more information than would be necessary to interact with only one complementary receptor site; therefore, the topography of the hormone exposed to the binding site may be different on contact with the receptors of different target cells. To further investigate this aspect, new methods for the isolation and characterization of functional receptors must be developed. We are investigating the use of chemically well-defined, biologically active, covalent hormone-macromolecule complexes for this purpose. Another approach utilizes model receptors with a recognition pattern similar to that of the biological receptor, as described in this communication for certain highly specific antibodies.
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PMID:Mechanism of alpha-melanotropin action. 20 1

Morphine and the opioid peptides leucine-enkephalin (leu-enk), methionine-enkephalin (met-enk) and beta-endorphin had no effect on basal cyclic AMP levels in rat cerebral cortex and hypothalamus, but each inhibited noradrenaline (NA)-stimulated cyclic AMP formation in both brain regions. This inhibition was reversed by naloxone. Naloxone did not reverse phentolamine- or propranolol-induced inhibition of NA-stimulated cyclic AMP formation. The increase in cyclic AMP formation induced by NaF or MnCl2 was unaffected by met-enk or morphine. These data suggest that in rat cerebral cortex and hypothalamus opiates bind to opiate receptors and that the opiate-receptor complex interferes with noradrenergic receptor activity.
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PMID:Effect of opioid peptides on L-noradrenaline-stimulated cyclic AMP formation in homogenates of rat cerebral cortex and hypothalamus. 21 Aug 78

The potencies of beta h-endorphin, Met (O)5-beta h-endorphin, and synthetic Leu5-beta h-endorphin have been compared in three bioassays of opioid activity, and in two radioimmunoassays. In all assays, a peptide isolated from hemodialysates from a psychotic patient behaved like Leu5-beta h-endorphin; it has been distinguished unambiguously from beta h-endorphin and Met(O)5-beta h-endorphin. Leu5-beta h-endorphin was one-fifth as potent as beta h-endorphin in guinea pig ileum myenteric plexus, but was only slightly less active in mouse vas deferens and in guinea pig brain opiate receptor binding assay. The low cross-reactivity of Leu5-beta h-endorphin relative to beta h-endorphin with an antiserum raised to beta-endorphin suggests that the preferred solution conformations of these peptides are different. In all bioassays beta h-endorphin was 2- to 3-fold less potent than beta c-endorphin.
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PMID:Pharmacological and immunological characterization of the Leu5 analogue of human beta-endorphin. 21 94

A cDNA fragment synthesized from mouse mRNA (ACTH/LPH mRNA) that codes for the precursor polypeptide containing corticotropin (ACTH), beta-lipotropin (LPH), and several other peptides has been cloned in bacteria. The mRNA was enriched for ACTH/LPH mRNA translational activity (to about 75%) prior to cDNA synthesis. It appears to contain about 1200 bases, of which approximately 450 bases are not translated. The cloned DNA fragment is complementary to the region of the mRNA coding for the protein fragment beta-LPH-(44--90); this contains all of the amino acids of [Met]-enkephalin (residues 61--65 of beta-LPH), most of the amino acids of beta-melanocyte-stimulating hormone, and all but the carboxy-terminal amino acid of beta-endorphin. Based on assignment of the amino acid sequence of mouse beta-LPH from the nucelic acid sequence, it appears that there is extensive homology of mouse beta-LPH with human and porcine beta-LPH. The data also establish the linkage between beta-melanocyte-stimulating hormone and beta-endorphin as a Lys-Arg sequence. It is hoped that this cloned DNA can be used as a probe to study the expression and structure of the ACTH/LPH gene.
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PMID:Corticotropin and beta-endorphin: construction and analysis of recombinant DNA complementary to mRNA for the common precursor. 22 16

The effects of intracerebroventricular (i.c.v.) or systemic injections of Met- or Leu-enkephalin, beta-endorphin, FK 33.824 (D-Ala2, MePhe4, Met(O5)-ol-enkephalin) and of morphine and naloxone have been studied in baboons, Papio papio, which spontaneously show photically induced epileptic responses. Animals were chronically implanted with epidural or deep recording electrodes and a cannula in one lateral ventricle, and tested whilst seated in a primate chair. In some animals the natural syndrome was enhanced by the prior administration of DL-allylglycine, 100--200 mg/kg, i.v. Met- or Leu-enkephalin, 1--10 mg, i.c.v., did not lead to any manifest focal or generalized seizure discharges. Nor did it lead to any consistent enhancement or reduction of photically induced myoclonic responses (as tested 5--10 min after injection). beta-Endorphin, 0.1--0.5 mg, i.c.v., did not enhance or impair photically induced myoclonic responses. FK 33.824, 0.1--0.5 mg, i.c.v., depressed respiration and slowed EEG background rhythms for 9--15 h. This was associated with a loss of myoclonic responses to photic stimulation. These effects were reversed for 20--40 min following the injection of naloxone, 1 mg/kg i.m. A depression of respiration and a slowing of EEG rhythms was seen beginning 5--20 min after FK 33.824, 2 or 4 mg/kg, i.v. The higher dose also abolished photically induced myoclonic responses. Naloxone, 1 mg/kg, definitively reversed these effects. Morphine, 5--10 mg i.c.v., tended to increase the latency to onset of generalized myoclonus during photic stimulation. Myoclonic responses were delayed or diminished after morphine, 5 mg/kg, i.m. Naloxone, 1--2 mg/kg i.m., reversed this effect. Naloxone, 0.2--5.0 mg/kg i.m., alone, did not significantly modify photically induced myoclonus, either in animals of low or high initial responsiveness, or in those pretreated with allylglycine.
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PMID:Effects of opiate-like peptides, morphine, and naloxone in the photosensitive baboon, Papio papio. 22 24

The synthesis and secretion of various intermediate pituitary proteins was studied by using dispersed intermediate pituitary cell suspensions. Control studies indicated that the isolated cells were obtained in good yield and that after more than 24 h in culture the isolated cells continued to synthesize a collection of proteins similar to those found in freshly extracted intermediate pituitary tissue. Rat intermediate pituitary cells synthesized a molecule (Mr = 30,000; called 30K) that contained antigenic determinants for beta-endorphin, gamma-lipotropin, corticotropin (ACTH), and 16K fragment (the NH2-terminal region of mouse tumor cell pro-ACTH/endorphin). This 30K molecule, two high molecular weight forms of ACTH(13K and 20K), and 16K fragment were all shown to be glycoproteins. Continuous labeling and pulse-chase incubations were used to define the intracellular biosynthetic processing of the 30K molecule. After a 15-min pulse incubation the 30K molecule was the only labeled protein containing antigenic determinants for beta-endorphin, gamma-lipotropin, ACTH, or 16K fragment. A beta-lipotropin-like molecule served as a biosynthetic intermediate in the production of proteins similar to beta-endorphin and gamma-lipotropin. Methionine-enkephalin and alpha-endorphin were not major products in the intermediate lobe cells. Molecules similar to alpha-melanocyte-stimulating hormone and corticotropin-like intermediate lobe peptide (ACTH(18-39)) were also derived from the same 30K molecule; 20K ACTH served as a biosynthetic intermediate in this conversion. In rat intermediate pituitary cells ACTH(1-39) was not a major final product of the intracellular biosynthetic processing of the 30K molecule. The 30K molecule also served as a precursor to a protein similar to mouse tumor cell 16K fragment and related smaller proteins. With rat intermediate pituitary cells, pulse-chase experiments utilizing [35S]methionine demonstrated almost quantitative conversion of the 30K precursor into labeled proteins similar to beta-endorphin and alpha-melanocyte-stimulating hormone. In the absence of added secretagogues, small amounts of all of the smaller proteins derived from the 30K precursor were secreted coordinately into the culture medium.
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PMID:Synthesis and secretion of corticotropins, melanotropins, and endorphins by rat intermediate pituitary cells. 22 38

Endorphins are peptides with opiate-like action synthesized in various tissue, e.g. in intestine and central nervous system. Exact characterization of opioid-specific receptors and sensitive biological test assays for opioids were prerequisites for the discovery of these substances. Met- and leu-enkephalin were the first endorphins discovered. Both are pentapeptides. One of them, namely met-enkephalin (H-Tyr-Gly-Gyl-Phe-Met-OH) is likely to be a fragment of the peptides alpha- and beta-endorphin, both showing opioid-like actions, as well as of beta-lipotropin, a polypeptide showing no opioid-like activity: all these peptides include the pentapeptide met-enkephalin within their molecules. beta-liportropin and ACTH are likely to be fragments of a common precursor. At least both enkephalins (which are studied better as yet than the other endorphins) are supposed to be formed in the soma of the neuron and transported to the nerve ending, where they are released. They seem to have the function of neuromodulator or even of neurotransmitters. The pharmacological actions of endorphins resemble those of "classical opiates", both having e.g. analgesic effects. Both enkephalins are, among various other brain and spinal cord areas, localized in those areas which seem to be of particular relevance for perception and transmission of pain. They might, under certain conditions, play some part in the regulation of pain perception. Furthermore, they seem to be relevant for some neuroendocrine processes. Their relevance in symptoms of schizophrenic psychoses seems to be more doubtful. In opiate dependence no significant alterations of endorphin concentrations could be observed as yet.
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PMID:[On the physiology and pharmacology of endorphins (author's transl)]. 22 45

The oligopeptides beta- and delta O-endorphin were isolated from porcine and bovine pituitary respectively. Their opiate activity was determined in the guinea pig ileum and compared to that of the pentapeptide methionine-enkephalin and morphine. The rank order of opioid activity was found to be: morphine greater than beta-endorphin = Met-enkephalin greater than delta O-Endorphin which lacks the four C-terminal amino acids of beta-endorphin displayed 60% of the activity of beta-endorphin. These results indicate, that C-terminal amino acids contribute little to the affinity of beta-endorphin for opiate receptors in the guinea pig ileum.
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PMID:Opioid activity of delta O-endorphin in the guinea pig ileum. 22 81


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