BCH 361 Lecture Notes - Lecture 7: Ramachandran Plot, Peptide
Document Summary
Conformation is mostly stabilized by many non-covalent bonds within the polypeptide chain stability is the tendency to maintain a native conformation. A single fold is expensive in terms of entropy: native fold must be energetically favorable over all other folds. Native fold must form a very large number of favorable, non-covalent interactions. Interaction of n-h and c=o of the peptide bond and between polar r groups. Electrostatic interactions: long-range strong interactions between permanently charged groups, salt-bridges, esp. buried in the hydrophobic environment strongly stabilize the protein. Hydrophobic effect: release of water molecules from the structured solvation layer around the molecule as protein folds increases the net entropy. Van der walls forces: medium-range weak attraction between all atoms contributes significantly to the stability in the interior of the protein peptide bond is a resonance hybrid, makes the bond rigid and nearly planar.