Sequence
Sequence — The ordered arrangement of amino acid residues in a peptide chain, written from N-terminus to C-terminus using single-letter or three-letter codes.
What Is a Peptide Sequence?
A peptide sequence is the ordered list of amino acid residues from N-terminus to C-terminus, written in one-letter (ACDEFG) or three-letter (Ala-Cys-Asp-Glu-Phe-Gly) code. The sequence is the primary structure and determines all higher-order conformation and biological activity.
Notation Conventions
- Direction: Always written N → C (left to right). H-YGGFL-OH = Leu-enkephalin
- Modifications: Ac- (N-terminal acetyl), -NH2 (C-terminal amide), pGlu (pyroglutamate)
- Sequencing: MS/MS fragmentation (b/y ions) and Edman degradation determine sequence
Frequently Asked Questions
What is Sequence?
The ordered arrangement of amino acid residues in a peptide chain, written from N-terminus to C-terminus using single-letter or three-letter codes.
Why is Sequence important in peptide research?
Sequence is a fundamental concept in biochemistry as it relates to peptide science. It directly influences experimental design, compound characterization, and the reliability of research outcomes across biochemistry and molecular biology disciplines.