peptide


peptide
/pep"tuyd/, n. Biochem.
a compound containing two or more amino acids in which the carboxyl group of one acid is linked to the amino group of the other.
[1905-10; PEPT(IC) + -IDE]

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Organic compound composed of a series of amino acids linked by peptide bonds (see covalent bond) between a carbon atom of one and a nitrogen atom of the next.

Peptide chains longer than a few dozen amino acids are called proteins. Biosynthesis of peptides from a succession of amino acids carried by transfer RNA molecules takes place on ribosomes and is catalyzed and controlled by enzymes. Many hormones, antibiotics, and other compounds that participate in life processes are peptides.

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      any organic substance of which the molecules are structurally like those of proteins, but smaller. The class of peptides includes many hormones, antibiotics, and other compounds that participate in the metabolic functions of living organisms. Peptide molecules are composed of two or more amino acids joined through amide formation involving the carboxyl group of each amino acid and the amino group of the next. The chemical bond between the carbon and nitrogen atoms of each amide group is called a peptide bond. Some or all of the peptide bonds, which connect the consecutive triplets of atoms in the chain regarded as the backbone of the molecule, can be broken by partial or complete hydrolysis of the compound. This reaction, producing smaller peptides and finally the individual amino acids, is commonly used in studies of the composition and structure of peptides and proteins.

      The number of amino-acid molecules present in a peptide is indicated by a prefix: a dipeptide contains two amino acids; an octapeptide, eight; an oligopeptide, a few; a polypeptide, many. The distinction between a polypeptide and a protein is imprecise and largely academic; some authorities have adopted, as an upper limit on the molecular weight of a polypeptide, 10,000 (that of a peptide composed of about 100 amino acids).

Additional Reading
An overview of peptides is found in Donald Voet and Judith G. Voet, Biochemistry, 3rd ed. (2004); and Theodor Wieland and Miklos Bodanszky, The World of Peptides (1991). Peptide synthesis is covered in Miklos Bodanszky, Principles of Peptide Synthesis, 2nd rev. ed. (1993); and N. Leo Benoiton, Chemistry of Peptide Synthesis (2006).

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Universalium. 2010.

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  • peptide — [ pɛptid ] n. m. • 1907; mot angl. 1906 ♦ Biochim. Enchaînement formé par un nombre restreint d acides aminés (contrairement aux polypeptides et aux protéines). ⇒ oligopeptide. Adj. PEPTIDIQUE . Liaison peptidique. ● peptide nom masculin… …   Encyclopédie Universelle

  • PEPTIDE P — Le peptide P (PP), ou polypeptide pancréatique, est sécrété de l’estomac au colon par les cellules EC1, mais il est avant tout d’origine pancréatique. Sa concentration augmente rapidement après un repas d’épreuve, mais son rôle physiologique… …   Encyclopédie Universelle

  • Peptide —   [zu griechisch peptós »gekocht«, »verdaut«], Singular Peptid das, (e)s, aus Aminosäuren aufgebaute, durch Peptidbindungen verknüpfte lineare Moleküle unterschiedlicher Größe, die in der Natur weit verbreitet vorkommen. Nach der Anzahl der in… …   Universal-Lexikon

  • peptide — peptide. См. пептид. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Peptide — Peptide, Produkte der Pepsinverdauung, die weder die Biuretreaktion geben, noch Aminosäuren sind; sie bilden Zwischenstufen zwischen letztern und den Peptonen. Synthetisch sind P. von Fischer dargestellt worden. Aminosäuren vermögen sich… …   Meyers Großes Konversations-Lexikon

  • Peptide — Peptide, durch Reaktion der Säuregruppe einer Aminosäure mit der Aminogruppe einer anderen Aminosäure entstandene organische Verbindung, in der die beteiligten Aminosäuren über die charakteristische P.bindung CO NH miteinander verknüpft sind. Dip …   Deutsch wörterbuch der biologie

  • peptide — PEPTÍDE s.f. pl. Substanţe chimice rezultate din desfacerea hidrolitică a proteinelor. [sg. peptidă. / < fr. peptides]. Trimis de LauraGellner, 13.09.2007. Sursa: DN …   Dicționar Român

  • peptide — 1906, from Ger. peptid, a back formation from dipeptid (1902), etc.; see PEPSIN (Cf. pepsin) …   Etymology dictionary

  • peptide — ► NOUN Biochemistry ▪ a compound consisting of two or more linked amino acids. ORIGIN German Peptid, from Polypeptid polypeptide …   English terms dictionary

  • peptide — [pep′tīd΄] n. [ PEPT(ONE) + IDE] any of a group of compounds formed from two or more amino acids by the linkage of amino groups of some of the acids with carboxyl groups of others, or by the hydrolysis of proteins …   English World dictionary


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