What Is/are the Primary Stabilizer(s)of α-Helices

Question

What is/are the primary stabilizer(s)of α-helices?
A)hydrogen bonds between the main-chain peptide bond component atoms
B)hydrophobic interactions between the α-carbons of the main chain
C)hydrogen bonding between the R groups
D)hydrophobic interactions between R groups and the solvent water

Accepted Answer

The primary stabilizers of α-helices are the hydrogen bonds between the main-chain peptide bond component atoms. These bonds form between the carbonyl group of one amino acid and the amide hydrogen of another amino acid, stabilizing the helical conformation. Hydrophobic interactions between the α-carbons and R groups would play a role in protein folding, but are not the primary stabilizers of α-helices. Hydrogen bonding between R groups and solvent water is not specific to α-helices and would not contribute to their stability.