You are studying a protein that you call Protein X. There is an aspartic acid at a key position in Protein X that is important in the folding and stabilization of that protein. If this aspartic acid is changed to a different amino acid, which one of the following amino acid substitutions is MOST likely to allow the protein to fold normally?
A)threonine
B)glycine
C)arginine
D)glutamic acid
E)serine

Question

Quizplus · Accepted Answer

Glutamic acid (D) is the most likely substitution to allow normal folding because it is structurally similar to aspartic acid, differing only by one extra methylene group in its side chain. Both are negatively charged at physiological pH, which helps in maintaining similar interactions that are crucial for the protein's folding and stabilization.

You Are Studying a Protein That You Call Protein X