Please help me with this question, 1. At pH 7.0, in what order would the followi

Question

Please help me with this question,

1. At pH 7.0, in what order would the following three peptides be eluted from a column filled with an anion-exchange polymer? Their amino acid compositions are:

Peptide A: Ala 10%, Glu 5%, Ser 5%, Leu 10%, Arg 10%, His 5%, Ile 10%, Phe 5%, Tyr 5%, Lys 10%, Gly 10%, Pro 5%, and Trp 10%.

Peptide B: Ala 10%, Glu 10%, Gly 5%, Leu 5%, Asp 10%, Arg 5%, Met 5%, Cys 5%, Tyr 5%, Phe 5%, His 5%, Val 5%, Pro 5%, Thr 5%, Ser 5%, Asn 5%, and Gln 5%.

Peptide C: Ala 5%, Val 5%, Gly 10%, Asp 5%, Leu 5%, Arg 5%, Ile 5%, Phe 5%, Tyr 5%, Lys 5%, Trp 5%, Ser 5%, Thr 5%, Glu 5%, Asn 5%, Pro 10%, Met 5%, and Cys 5%.

First off column: _______________ Second: _______________ Last off column: _______________

Explanation / Answer

Protein B is Highly Negative in charge due to presence of Glu 10% and Asp 10% with no Lys and Arg residues. Protein A is highly positive due to presence of residues like Lys 10%,His 5% and Arg 10% .in larger numbers than the quantity of negative amino acids. Protein C is Neutral due to presence of all the positive and negative residues in nearly equal quantities. An anion exchange polymer has a positive charge. So, protein A (positive) will be eluded first because it will repel the positive charge of polymer, then Protein C will be eluded being no net charge, later on protein B will be eluded.

First off column: Protein A

Second : Protein C

Last off column : Protein B

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.