Phenylketonuria is caused by mutations in the enzyme phenyla

Phenylketonuria is caused by mutations in the enzyme phenylalanine hydroxylase (PAH), which significantly reduce its enzymatic activity causing abnormally high levels of phenylalanine in the patients’ blood and urine. The most common mutation associated with the disease is the change Arg408Trp at the surface of the protein. Give a possible explanation as to why this mutation would problematic for PAH structure and function.

Solution

Arginine is a charged molecule at surface area in this PAH. which is replaced by tryptophan which a hydrophobicolar (usually participate in hydrogen bonds as proton donors or acceptors). Introduction of a different charge at the surface of the protein may provide a new interaction on the protein surface.