You are given a solution of "protein X". Protein X consists of 250 amino acid residues: 38% are valine, 24% are alanine, 20% are glycine, and 18% are isoleucine. What is the molecular weight of protein X? Describe how you determined this answer.
According to the problem, the 250-amino acid protein X is made of 38% valine, 24% alanine, 20% glycine, and 18% isoleucine. Since only the protein length is given, it will be assumed that the percentage values are based on the number of residues. The number of residues per type of amino acid can be computed as:
nAAresidue = Namino acids*(Percentage)
nvaline = 250*0.38 = 95
Thus, the protein will be made up of 95 valine residues, 60 alanine, 50 glycine, and 45 isoleucine residues.