Polypeptide
A compound consisting of 2 or more amino acids. Amino acids make up polypeptides which, in turn, make up proteins.
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A peptide formed by the union of an indefinite (usually large) number of amino acid s by peptide links (–NH–CO–).
- gastric inhibitory p. (GIP) a peptide hormone secreted by the stomach; GIP inhibits the secretion of acids and of pepsin and stimulates insulin release as part of the digestive process. SYN: gastric inhibitory peptide.
- glucose-dependent insulinotropic p. an insulinotropic substance originating in the gastrointestinal tract and released into the circulation following ingestion of a meal containing glucose.
- pancreatic p. 1. a 36-amino acid peptide secreted by islet cells of the pancreas in response to a meal and of uncertain physiologic function; 2. a family of gastrointestinal peptides, which includes pancreatic p., neuropeptide Y, and peptide YY.
- trefoil p. a group of polypeptides that share the trefoil moiety of a highly stable three-loop structure held together by disulfide bonds based on cysteine residues; they are widely expressed in gastrointestinal tissues and secreted by mucous cells; their functions are as yet unknown.
- vasoactive intestinal p. (VIP) a p. hormone secreted most commonly by non-β islet cell tumors of the pancreas; VIP increases the rate of glycogenolysis and stimulates pancreatic bicarbonate secretion; excess production causes copious watery diarrhea and fecal electrolyte loss, with hypokalemia and hypochlorhydria. SYN: vasoactive intestinal peptide.

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poly·pep·tide .päl-i-'pep-.tīd n a molecular chain of amino acids
poly·pep·tid·ic -(.)pep-'tid-ik adj

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n.
a molecule consisting of three or more amino acids linked together by peptide bonds. protein molecules are polypeptides.

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poly·pep·tide (pol″e-pepґtīd) [poly- + peptide] a peptide that on hydrolysis yields more than two amino acids; called tripeptides, tetrapeptides, and so on according to the number of amino acids contained. See also peptide.

Medical dictionary. 2011.

Look at other dictionaries:

  • polypeptide — [ pɔlipɛptid ] n. m. • 1903; de poly et peptide ♦ Biochim. Substance constituée par la combinaison de plusieurs acides aminés, en nombre supérieur à quatre. Polypeptides naturels, synthétiques. Polypeptides résultant de la digestion des protéines …   Encyclopédie Universelle

  • Polypeptide — ⇒ Peptide …   Deutsch wörterbuch der biologie

  • polypeptide — (n.) peptide built from a large number of amino acids, 1903, from Ger. polypeptid; see POLY (Cf. poly ) + PEPTIDE (Cf. peptide) …   Etymology dictionary

  • polypeptide — [päl΄i pep′tīd΄] n. [ POLY + PEPTIDE] a substance containing two or more amino acids in the molecule joined together by peptide bonds …   English World dictionary

  • Polypeptide — Ein Peptid ist eine organische chemische Verbindung, die aus einer Verknüpfung mehrerer Aminosäuren entstanden ist[1]. Dabei sind die einzelnen Aminosäuren in einer definierten Reihenfolge (Sequenz) zu einer, meist unverzweigten, Kette verbunden …   Deutsch Wikipedia

  • Polypeptide — Un polypeptide est une chaîne de 10 à 100 acides aminés reliés par des liaisons peptidiques. Parmi eux, les peptides multi cycliques, les peptides phosphorylés ou encore ceux intégrant des liaisons non peptidiques ou des peptides conjugués.… …   Wikipédia en Français

  • polypeptide — Chains of a amino acids joined by peptide bonds. Distinction between peptides, oligopeptides and polypeptides is arbitrarily by length; a polypeptide is perhaps more than 10 residues …   Dictionary of molecular biology

  • polypeptide — polipeptidas statusas T sritis chemija apibrėžtis Peptidas, kurio molekulė susideda iš daug α aminorūgščių liekanų. atitikmenys: angl. polypeptide rus. полипептид …   Chemijos terminų aiškinamasis žodynas

  • polypeptide — polipeptidas statusas T sritis augalininkystė apibrėžtis Aminorūgščių, sujungtų peptidiniais ryšiais į linijinę struktūrą, seka. atitikmenys: angl. polypeptide rus. полипептид …   Žemės ūkio augalų selekcijos ir sėklininkystės terminų žodynas

  • polypeptide — noun Etymology: International Scientific Vocabulary Date: 1903 a molecular chain of amino acids • polypeptidic adjective …   New Collegiate Dictionary

  • polypeptide — /pol ee pep tuyd, tid/, n. Biochem. a chain of amino acids linked together by peptide bonds and having a molecular weight of up to about 10,000. [1900 05; POLY + PEPTIDE] * * * …   Universalium

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