a) Assume that each of the three proteins contains a single polypeptide chain. E
ID: 33594 • Letter: A
Question
a) Assume that each of the three proteins contains a single polypeptide chain. Estimate the number of amino acids in each protein. b) A mixture of the three proteins is passed over a size exclusion column. Predict the elution profile. c) A mixture of the three proteins is applied to a cation exchange column at pH 5. Unbound protein is washed off the column, then bound protein is eluted with a NaCl gradient. Predict the elution profile, including what gets washed off initially. d) A mixture of the three proteins is applied to an anion exchange column at pH 5. Unbound protein is washed off the column, then bound protein is eluted with a NaCI gradient. Predict the elution profile, including what gets washed off initially.Explanation / Answer
a)
b)
In size exclusion chromatography larger molecules elutes first and smaller molecules elutes last, thus the protein-A elute first and both protein-C and protein-B elutes at the same time due to having same molecular weight.
c)
Here, the protein rich with anionic amino acids (Asp and Glu) would more likely bound to the Column, because the given column is cation exchange column. In the given sample, the protein-A has more amount of Aspartic acid and Glutamic acid, which is followed by protein-C and then protein-B. Thus, the protein-B elutes first, then protein –C and ultimately protein-A is eluted from the column.
d)
Here, the protein rich with cationic amino acids (Lys and Arg) would more likely bound to the Column, because the given column is an anion exchange column. In the given sample, the protein-A has more amount of Lysine and arginine, which is followed by protein-C and then protein-B. Thus, the protein-B elutes first, then protein –C and ultimately protein-A is eluted from the column.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.