Question

Explain why glutamine side chain might be located inside of a correctly folded protein. (i.e not interacting with water)

Answer 1

When polar amino acids are buried within the protein, they are usually hydrogen-bonded to other polar amino acids or to the polypeptide. In such case glutamine side chain might be located inside of a correctly folded protein. The reason is as follows.

The nonpolar or hydrophobic possessing side chains (in a protein) amino acids as phenylalanine, leucine, valine, and tryptophan tend to cluster in the interior of the molecule. This enables them to inhibit contact with the water that surrounds them inside a cell.

On the otherhand, polar side chains containing amino acids such as arginine, glutamine, and histidine—tend to arrange themselves near the outside of the molecule, where they can form hydrogen bonds with water and with other polar molecules.

When polar amino acids are buried within the protein, they are usually hydrogen-bonded to other polar amino acids or to the polypeptide. In such case glutamine side chain might be located inside of a correctly folded protein.

Thank You So Much! Please Rate this answer as you wish.