This exhibit shows a few examples of the types of chemical bonds that play important roles in stabilizing 3-D protein structure. Covalent Bonds - Disulfide Bridges Covalent bonds are the strongest chemical bonds contributing to protein structure.
Covalent bonds arise when two atoms share electrons .
In addition to the covalent bonds that connect the atoms of a single amino acid and the covalent peptide bond that links amino acids in a protein chain, covalent bonds between cysteine side chains can be important determinants of protein structure. Ionic bonds are formed as amino acids bearing opposite electrical charges are juxtaposed in the hydrophobic core of proteins. Ionic bonding in the interior is rare because most charged amino acids lie on the protein surface. Although rare, ionic bonds can be important to protein structure because they are potent electrostatic attractions that can approach the strength of covalent bonds . B. Water Shells and Charged Surface Residues Electrically charged amino acids, mostly found on protein surfaces, promote appropriate folding by interacting with the water solvent.