Why alpha helix is stable?

The alpha helix is stable primarily due to hydrogen bonding between the carbonyl oxygen of one amino acid and the hydrogen of the amide group of another amino acid located four residues earlier in the sequence. This pattern of bonding creates a regular, repeating structure that minimizes steric clashes and contributes to the overall stability of the helix. Additionally, the helical conformation allows for efficient packing of side chains, further enhancing its stability. The overall hydrophobic interactions and the intrinsic properties of the amino acids also play a role in maintaining this structural integrity.