Protein Secondary Structure Energy Landscape
Ramachandran plot — φ/ψ backbone dihedral angles and H-bond energetics
φ (phi) °
-60°
ψ (psi) °
-45°
Residues N
12
Structure
Custom φ/ψ
α-Helix
β-Sheet (anti)
π-Helix
3₁₀-Helix
Polyproline II
α-helix: φ=−60°, ψ=−45°. H-bonds from NH(i+4) to CO(i). Rise: 1.5 Å/residue, 3.6 res/turn.