Definition
The ordered list of amino acids in a peptide, written from N-terminus to C-terminus.

Detailed Explanation

The ordered list of amino acids in a peptide, written from N-terminus to C-terminus. Sequences are expressed in either one-letter code (e.g., CYFQNCPRG for oxytocin) or three-letter code (e.g., Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-Gly). The sequence is the primary structure of a peptide and determines all higher-order properties — folding, function, receptor binding, and biological activity.

Sequence is determined experimentally by Edman degradation or mass spectrometry (MS/MS). Sequence databases include UniProt (proteins) and the Antimicrobial Peptide Database (AMPs). Even single amino acid changes in a sequence can dramatically alter function — oxytocin and vasopressin differ by just 2 of 9 residues.

Key Facts

  • The ordered list of amino acids in a peptide, written from N-terminus to C-terminus.
  • Sequences are expressed in either one-letter code (e.g., CYFQNCPRG for oxytocin) or three-letter code (e.g., Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-Gly).
  • The sequence is the primary structure of a peptide and determines all higher-order properties — folding, function, receptor binding, and biological activity.
  • Sequence is determined experimentally by Edman degradation or mass spectrometry (MS/MS).
  • Sequence databases include UniProt (proteins) and the Antimicrobial Peptide Database (AMPs).
  • Even single amino acid changes in a sequence can dramatically alter function — oxytocin and vasopressin differ by just 2 of 9 residues.
Related Terms N Terminus C Terminus Edman Degradation Mass Spectrometry Residue Amino Acid

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