| peptide bond | The amide linkage between the carboxyl group of one amino acid and the amino group of another. The linkage does not allow free rotation and can occur in cis or trans configuration, the latter the most common in natural peptides, except for links to the amino group of proline, which are always cis. (18 Nov 1997) |
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| peptide chain elongation | The process whereby an amino acid is joined through a substituted amide linkage to a chain of peptides. (12 Dec 1998) |
| peptide chain initiation | The process whereby the formation of a peptide chain is started. This process requires (1) the 30s subunit, (2) the mRNA coding for the polypeptide to be made, (3) met-trnai, (4) initiation factors, and (5) GTP. (12 Dec 1998) |
| peptide chain termination | The process whereby the last amino acid is added to a polypeptide. This termination is signaled by one of three termination triplets in the mRNA, immediately following the last amino acid codon. (12 Dec 1998) |
| peptide deformylase | <enzyme> Fms is a zinc-containing protein showing homologies with zinc aminopeptidases; its enzyme function resembles that of an aminopeptidase; has been sequenced; mol mass 19,207 da Registry number: EC 3.4.11.- Synonym: fms protein, fms gene product (26 Jun 1999) |
| peptide elongation factors | Protein factors uniquely required during the elongation phase of protein synthesis. (12 Dec 1998) |
| peptide elongation factor tu | A protein found in bacteria and eukaryotic cells which delivers aminoacyl-trna's to the a site of the ribosome. The aminoacyl-trna is first bound to a complex of elongation factor tu containing a molecule of bound GTP. The resulting complex is then bound to the 70s initiation complex. Simultaneously the GTP is hydrolyzed and a tu-GDP complex is released from the 70s ribosome. The tu-GTP complex is regenerated from the tu-GDP complex by the ts elongation factor and GTP. (12 Dec 1998) |
| peptide hormone inactivating endopeptidase | <enzyme> From xenopus laevis; cleaves at xaa-phe, xaa-leu or xaa-ile bonds where xaa = ser, phe, tyr, his or gly in peptide hormones Registry number: EC 3.4.24.- Synonym: phie, xenopus (26 Jun 1999) |
| peptide hydrolases | <enzyme> Registry number: EC 3.4 (12 Dec 1998) |
| peptide initiation factors | Protein factors uniquely required during the initiation phase of protein synthesis. (12 Dec 1998) |
| peptide library | A collection of cloned free peptides, frequently consisting of all possible combinations of amino acids making up an n-amino acid peptide. (12 Dec 1998) |
| peptide map | Proteases will produce fragments of a characteristic size from a protein and this can be used as a test for the identity or otherwise of two similar sized proteins. It is possible to produce a peptide fragment map from a single gel band. (18 Nov 1997) |
| peptide mapping | Two-dimensional separation and analysis of peptides. (12 Dec 1998) |
| peptide N-alpha acetyltransferase | <enzyme> Pituitary enzyme; acetylates peptide hormones including acth; also found in saccharomyces cerevisiae Registry number: EC 2.3.1.88 Synonym: peptide acetyltransferase, acth acetyltransferase, beta-endorphin acetyltransferase, alpha-msh acetyltransferase (26 Jun 1999) |
| peptide neurotransmitter | Small peptides used as primary or co transmitters in nerve cells for example FMRF amide, FLRFamide. (18 Nov 1997) |