Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of an amino acid derivative (N-benzoyl-L-argininamide), four small peptides (Phe-Gly-Phe-Gly, gastrin-related peptide (Trp-Met-Arg-Phe-NH2), tetragastrin (Trp-Met-Asp-Phe-NH2), pentagastrin (Boc-beta Ala-Trp-Met-Asp-Phe-NH2] and one medium-sized peptide, glucagon (29 residues), on the gel-to-liquid crystalline transition of a multilamellar suspension of dimyristoylphosphatidylcholine have been studied by means of high-sensitivity differential scanning calorimetry. At low concentrations of added solutes, the temperature at which the excess apparent specific heat in the gel-to-liquid crystalline phase transition of the lipid is maximal is lowered by an amount proportional to the total concentration of the peptide, with proportionality constants ranging from -0.018 K mM-1 for Phe-Gly-Phe-Gly to -3.1 K mM-1 for the gastrin-related peptide. The lipid mixtures involving the first two solutes listed above exhibited approximately symmetrical curves of excess apparent specific heat vs. temperature. The curves for the other solutes were asymmetric, and could be well represented as the sum of either two or three two-state curves. The asymmetry, which was especially pronounced in the cases of pentagastrin and glucagon, thus appeared to be due to the presence of components having lower and/or higher transition temperatures than that of the lipid. Pentagastrin and glucagon (R.M. Epand and J.M. Sturtevant, Biochemistry 20 (1981) 4603) have much smaller effects on the gel-to-liquid crystalline phase transition of dipalmitoylphosphatidylcholine than on that of the dimyristoyl analog.
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PMID:The effects of various peptides on the thermotropic properties of phosphatidylcholine bilayers. 654 24

A novel form of the polypeptide termed PHI (peptide HI with N-terminal histidine and C-terminal isoleucine amide) has been isolated from bovine upper intestine. This bovine peptide was obtained in a 40 times higher yield than the corresponding polypeptide isolated from porcine intestine. Bovine PHI is, like porcine PHI, composed of 27 amino acid residues. The complete amino acid sequence of the bovine peptide is His-Ala-Asp-Gly-Val-Phe-Thr-Ser-Asp-Tyr-Ser-Arg-Leu-Leu-Gly-Gln-Leu-Ser- Ala- Lys-Lys-Tyr-Leu-Glu-Ser-Leu-Ile-NH2. This sequence differs from porcine PHI at position 10 and from human PHI at positions 10, 12 and 27. The amino acid residue exchange between porcine and bovine PHI makes the latter more similar to the vasoactive intestinal polypeptide (VIP), gastric inhibitory polypeptide (GIP), glucagon and the growth-hormone-releasing factor (GRF).
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PMID:A novel form of the polypeptide PHI isolated in high yield from bovine upper intestine. Relationships to other peptides of the glucagon-secretin family. 654 46

To investigate the role of the leader peptide in modulating secretion from living cells, we injected a synthetic peptide into Xenopus oocytes. The peptide consisted of the NH2-terminal leader sequence of mouse immunoglobulin light chain precursor. We found that the leader peptide has two different roles in regulating secretion from the oocytes. First, it competitively inhibits the synthesis of secretory and membrane proteins but not of cytoplasmic proteins. The inhibition occurs both with oocyte proteins and with proteins directed by coinjected myeloma mRNA. The inhibition reaches a maximum 2 hr after injection and decays within 3 hr. It appears to be mediated through the cell membrane, because 125I-labeled leader peptide segregates into the membrane fraction of microinjected oocytes simultaneously with the interference with methionine incorporation. A second role of the microinjected leader peptide is to induce a rapid acceleration in the rate of export of secretory proteins from the oocyte. The maximal enhancement effect is obtained upon injection of 50 ng of leader peptide per oocyte. It is not merely due to the small size, negative charge, or hydrophobicity of the peptide, because enhanced secretion does not occur when glucagon, poly-L-glutamic acid, or Triton X-100 is injected. Furthermore, immunoreaction of the peptide with specific antibodies prior to microinjection prevents the accelerated export. Our observations indicate that in Xenopus oocytes, the leader peptide is involved in both translocation and later step(s) in the secretory pathway.
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PMID:Synthetic leader peptide modulates secretion of proteins from microinjected Xenopus oocytes. 658 Jun 39

Two cardioacceleratory peptides from the corpora cardiaca of Periplaneta americana have been purified by gel filtration and reversed-phase liquid chromatography, Based on analysis of the intact factors and their chymotryptic fragments, we have assigned the primary structure of these octapeptides as pGlu-Val-Asn-Phe-Ser-Pro-Asn-Trp-NH2, designated periplanetin CC-1, and pGlu-Leu-Thr-Phe-Thr-Pro-Asn-Trp-NH2, designated periplanetin CC-2. They represent new members of a family of invertebrate peptides that includes locust adipokinetic hormone and crustacean red-pigment concentrating hormone. Both peptides show adipokinetic activity in grasshoppers and hyperglycemic activity in cockroaches. One of these peptides (CC-2) has provocative sequence homology with the NH2-terminal portion of glucagon.
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PMID:Isolation and primary structure of two peptides with cardioacceleratory and hyperglycemic activity from the corpora cardiaca of Periplaneta americana. 659 Dec 5

A new peptide, designated PHI (PHI-27), has been discovered and isolated from porcine upper intestinal tissue by using a chemical method for finding peptide hormones and other active peptides. The method is based on chemical detection of peptides having the cOOH-terminal alpha-amide structure, which is an unusual chemical feature of some peptide hormones and active peptides. Porcine PHI was found in the intestinal extract by the presence of its COOH-terminal isoleucine amide structure. It consists of 27 amino acid residues and has the following amino acid sequence: His-Ala-Asp-Gly-Val-Phe-Thr-Ser-Asp-Phe-Ser-Arg-Leu-Leu-Gly-Gln-Leu-Ser-Ala-Lys -Lys-Tyr-Leu-Glu-Ser-Leu-Ile-NH2. The remarkable sequence homology of PHI to the vasoactive intestinal peptide, secretin, glucagon, and gastric inhibitory polypeptide indicates that this peptide is a member of the glucagon-secretin family. Several biological activities of PHI, similar to those of vasoactive intestinal peptide and secretin, have been reported.
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PMID:Isolation and characterization of the intestinal peptide porcine PHI (PHI-27), a new member of the glucagon--secretin family. 694 44

Seven patients undergoing cholcystektomy received a 5 pevcent solution of alanine (90 mg/kg/h) during a period of 8 hours on the 1. postoperative day. Stimulation of gluconeogenesis was observed with increase of glucose from 5,9 +/- 0,2 to 6,3 +/- 0,2 mmol/l. Initially the level of ketone bodies decreased (acetoacetate 70 +/- 23 to 17 +/- 6 mumol/l) but again increased to start values during infusion of alanine. Insulin increased twofold from 7,6 +/- 1,4 microU/ml to 14,6 +/- 4,0, and had a constant level during infusion as did glucagon, which increased from 561 +/- 70 to 608 +/- 74 pg/ml. Nitrogen balance during infusionsperiod was almost zero (0,04 +/- 0,09 g/h minus) showing a significant difference to balances calculated from periods before and after infusion of alanine (0,57 +/- 0,07 and 0,53 +/- 0,06 g/h deficit respectively). Direct influence on peripheral glucose alanine cycle and increased gluconeogenetic substrate seem to be responsible for the nitrogen sparing effect of alanine.
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PMID:[Changes in glucose, fat and hormone balance induced by the postoperative administration of alanine solution]. 700 42

We have constructed and cloned in bacteria recombinant plasmids containing DNA complementary to the mRNA encoding a pancreatic preproglucagon (Mr 14,500), a product of cell-free translation of angler fish islet mRNAs shown previously by immunoprecipitation analyses to be a precursor of glucagon. cDNAs of 630, 180, and 120 base pairs were isolated and correspond to most of the mRNA for the preproglucagon (650 bases). The cDNAs contain a protein coding sequence of 372 nucleotides and 5'- and 3'-untranslated regions of 58 and 206 nucleotides, respectively. From the coding sequence of the cDNAs, we find that the sequence of glucagon, identical to mammalian glucagon in 20 of 29 positions, resides in the preproglucagon of 124 amino acids flanked by NH2- and COOH-peptide extensions of 52 and 43 amino acids, respectively. The peptide extensions are linked to the glucagon by Lys-Arg sequences characteristic of the sites that are cleaved during the posttranslational processing of prohormones. Notable is the finding that, following the initial Lys-Arg sequence in the COOH-peptide extension is a pentapeptide. Ser-Gly-Val-Ala-Glu, followed by another Lys-Arg and a sequence of 34 residues that shows striking homology with glucagon and the other peptides of the glucagon family--gastric inhibitory peptide, vasoactive intestinal peptide, and secretin. Thus, the preproglucagon mRNA contains two glucagon-related coding sequences arranged in tandem. The finding of Lys-Arg sequences flanking the glucagon and glucagon-related sequences suggests that these two peptides and a pentapeptide are formed in vivo by posttranslational cleavages of a common precursor.
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PMID:Pancreatic preproglucagon cDNA contains two glucagon-related coding sequences arranged in tandem. 704 59

Glucagon can bind to terbium, resulting in a 1000-fold enhancement of terbium fluorescence. This process is critically dependent on pH and apparently requires that the NH2-terminal histidine residue of glucagon be in an unprotonated form. The terbium ion can be displaced by zinc but not readily by calcium. The binding of zinc or terbium to glucagon induces a large conformational change in the peptide resulting in a shift in the fluorescence emission maximum of glucagon from 352 to 339 mm and in a marked increase in the helix content of the peptide. Similar conformational changes occur with this peptide upon self-association or upon binding to lipids.
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PMID:Cation-induced conformational change in glucagon. 712 44

Cardiac work increased protein synthesis in hearts supplied glucose (mixture 1), glucose-insulin-glucagon-lactate-beta-hydroxybutyrate (mixture 2) or palmitate-beta-hydroxybutyrate-glucose (mixture 3). In hearts provided mixture 1, acceleration of synthesis involved increased rates of peptide chain initiation. In these hearts intracellular concentrations of 5 amino acids decreased and 13 others were unchanged, indicating that faster protein synthesis did not depend on increased amino acid availability. In hearts supplied mixtures 2, 3, or 4 (lactate-glucose-insulin), intracellular concentrations of branched-chain amino acids were decreased by work, whereas intracellular levels of some acidic and neutral amino acids increased. Protein degradation was decreased by work in hearts supplied mixtures 1 and 2, but not mixtures 3 and 4. In hearts provided mixture 1, nitrogen balance was negative, but less so in working preparations. Nitrogen balance was zero or positive in working hearts provided mixtures 2 and 4. These studies indicated that in hearts supplied some, but not all, of the substrate mixtures, cardiac work maintained efficiently of protein synthesis and inhibited protein degradation. An improved method for perfusion of working hearts with albumin-containing buffer is described.
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PMID:Regulation of protein synthesis and degradation during in vitro cardiac work. 737 41

Chicken secretin has been isolated and its structure determined. It is composed of 27 amino acid residues, and has an amidated C terminus. The amino acid sequence is His-Ser-Asp-Gly-Leu-Phe-Thr-Ser-Glu-Tyr-Ser-Lys-Met-Arg-Gly-Asn-Ala-Gln-Val-Gln -Lys-Phe-Ile-Gln-Asn-Leu-Met-NH2. The structure shows distinct similarities to that of porcine secretin, amino acid identities occur at 14 positions (residues 1-4, 6-9, 11, 14, 17, 20, 24 and 26) but considerable differences are also present among the remaining 13 positions. Chicken secretin further shows a clear structural similarity to the vasoactive intestinal peptide (37% identical positions), the gastric inhibitory peptide (30% identical positions) and to glucagon (52% identical positions), suggesting wide evolutionary and functional relationships.
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PMID:Isolation and characterization of chicken secretin. 746 Sep 28


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