Ramachandran Plot
Ramachandran Plot — A graphical representation of the backbone dihedral angles of amino acid residues, used to validate peptide and protein structural models.
What Is a Ramachandran Plot?
A Ramachandran plot maps the phi (φ) and psi (ψ) backbone dihedral angles for each residue in a peptide. Steric clashes between backbone and side-chain atoms restrict most phi/psi combinations, leaving defined "allowed regions" corresponding to alpha-helix, beta-sheet, and left-handed helix conformations.
Allowed Regions
- Alpha-helix: φ ≈ -57°, ψ ≈ -47°
- Beta-sheet: φ ≈ -120°, ψ ≈ +120°
- Gly: No side chain. All phi/psi combinations allowed (most flexible residue)
- Pro: Cyclic side chain fixes φ ≈ -60° (most constrained residue)
Frequently Asked Questions
What is Ramachandran Plot?
A graphical representation of the backbone dihedral angles of amino acid residues, used to validate peptide and protein structural models.
Why is Ramachandran Plot important in peptide research?
Ramachandran Plot is a fundamental concept in analytical 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.
Authority Sources
- Ramachandran Plot on Wikipedia
- Search Ramachandran Plot on PubChem (NIH)
- Research articles on ScienceDirect