Question

1. Name one amino acid that can replace glutamine in a protein without the likelihood of causing a functional effect on the protein? Explain your answer.

Answer 1

There are 20 amino acids that occur in various combinations in proteins. The difference in physicochemical properties of amino acids allow them to produce many kinds of proteins and influence the function of proteins. The properties of amino acids include charge, hydrophilic or hydrophobic nature, size and functional groups on side chains categorize tem into different classes and contribute to difference in protein function. Some amino acids with certain properties can be replaced with amino acids with same properties and this would not alter or affect the function of protein. The glutamine (Gln or Q) is an amino acid that contains amide and polar side chain with neutral charge. This glutamine can be replaced with amino acid of same properties like Aspargine (Asn or N). The Aspargine is also amino acid containing amide and polar side chain with neutral charge. Both the glutamine and aspargine have hydropathy index of -3.5. There is slight variation in molecular weights of these two amino acids. But, glutamine replaced with aspargine may result in protein with no effect on the protein function.