The one that does not stabilize 2$$^\circ$$ and 3$$^\circ$$ structures of proteins is

The secondary and tertiary structures of proteins are stabilized by:

- Hydrogen bonding (key in secondary structure: alpha-helix and beta-sheet)

- Disulphide linkage (-S-S-) (covalent bond between cysteine residues)

- Van der Waals forces (weak intermolecular interactions)

- Ionic bonds (salt bridges)

- Hydrophobic interactions

The -O-O- linkage (peroxide linkage) does NOT play a role in stabilizing protein structures. It is not a natural bond found in protein stabilization.

The correct answer is Option 3: -O-O- linkage.