You have accidentally mixed a bunch of amino acids (tryptophan, tyrosine, alanine, selenocysteine, proline, arginine) together...

You have accidentally mixed a bunch of amino acids (tryptophan, tyrosine, alanine, selenocysteine, proline, arginine) together and once your boss finds out, you will be fired on the spot. Your only hope of saving your job is to separate them before anyone finds out. You decide that the only viable option is to use ion exchange chromatography. Explain, in detail, how you would do this?

Solutions

Expert Solution

Ion exchange chromatography involves the separation of ionizable molecules based on their total charge. This technique enables the separation of similar types of molecules that would be difficult to separate by other techniques because the charge carried by the molecule of interest can be readily manipulated by changing buffer pH. The amino acids that form proteins are zwitterionic compounds that contain both positively and negatively charged chemical groups. Depending on the pH of their environment, amino acids may carry a net positive charge, a net negative charge, or no charge. The pH at which a molecule has no net charge is called its isoelectric point, or pI.

The pI value can be calculated based on the primary sequence of the molecule.

In a buffer with a pH greater than the pI of the amino acid, the amino acid will carry a net negative charge; therefore, a positively charged anion exchange resin is chosen to capture this amino acid.

In a buffer with a pH lower than the pI of the amino acid, then it will carry a positive net charge; thus a negatively-charged cation exchange resin is chosen.

When an ion exchange chromatography column is loaded with a sample at a particular pH, all amino acids that are appropriately charged will bind to the resin. For example, if an anion exchange resin is chosen, all amino acids that are negatively charged at the loading buffer pH will bind to the positively charged column resin. A good rule of thumb for choosing a buffer pH is the following:

Anion exchanger — 0.5–1.5 pH units greater than the pI of the amino acids
Cation exchanger — 0.5–1.5 pH units less than the pI of the amino acid

queen_honey_blossom answered 1 year ago

Next > < Previous

Related Solutions

Which of these amino acids doesn't fit with the others? Alanine Glycine Serine Proline

Which amino acid is the most hydrophobic? (1pt) Arginine Aspartic Acid Leucine Serine Tyrosine

Glycine and proline are both non-polar amino acids, and both are very likely to be found...

Glycine and proline are both non-polar amino acids, and both are very likely to be found at the surface of proteins. What physical characteristic of each is responsible for this observation? 1) Both glycine and proline are small. 2) Glycine is small, and proline is rigid. 3) The side chains of both these amino acids make favorable interactions with molecules near the surface of proteins. 4) Both amino acids make strong interactions with each other and therefore are likely to...

How do the amino acids aspartate and alanine provide a source of carbon for gluconeogenesis? Write...

How do the amino acids aspartate and alanine provide a source of carbon for gluconeogenesis? Write out the structures for the interconversions of these amino acids and their corresponding deaminated (amino group removed) α-keto acids.

(THIS IS A MIXTURE OF ALL OF THE FOLLOWING ACIDS AND BASES MIXED TOGETHER WHERE A...

(THIS IS A MIXTURE OF ALL OF THE FOLLOWING ACIDS AND BASES MIXED TOGETHER WHERE A COMBINED pH IS WHAT I AM LOOKING FOR) 1. I have 0.500 Liters of water. To that 0.500 Liters, I add the following: a. 0.100 moles HCl b. 0.100 moles HOAc c. 0.100 moles NH4Cl d. 0.100 moles HF e. 0.050 moles NaOH f. 0.050 moles NaOAc g. 0.050 moles Mg(OH)2 What is the pH of the resulting mixture of everything? Dissociation constants of...

Turkey (protein) has many essential amino acids such as tryptophan, threonine, isoleucine, lysine and phenylalanine. Threonine...

Turkey (protein) has many essential amino acids such as tryptophan, threonine, isoleucine, lysine and phenylalanine. Threonine is a large amino acid and will broken be down into two products: pyruvate and succinyl CoA which are then fed into the citric acid cycle and electron transport chain. Phenylalalanine is broken down into acetyl CoA and fumarate and fed into the citric acid cycle and electron transport chain. Mayonnaise (fatty acid) has omega 3 alpha linolenic acid (18:3Δ9,12,15) and omega 6 linoleic...

How many different primary structures could be formed using the four amino acids alanine, phenylalanine, serine...

How many different primary structures could be formed using the four amino acids alanine, phenylalanine, serine and valine? Write the amino acid sequences (using the three letter code) of all the possible peptides that begin with phenylalanine. You must use each amino acid once and only once in each peptide.

Proteins are ______________ built from amino acids, which each have an amino group

Proteins are ______________ built from amino acids, which each have an amino group and a _____________ group attached to the central _______________. There are twenty possible _______________ that differ in structure and are generally referred to as “R.” In solutions of neutral pH, amino acids are _______________, carrying both a positive and negative charge. When a protein is made, amino acids are linked together through _______________, which are formed by condensation reactions between the carboxyl end of the last amino...

1.What type of bond holds amino acids together in a polypeptide chain? A. Peptide Bond B....

1.What type of bond holds amino acids together in a polypeptide chain? A. Peptide Bond B. Phosphodiester Bond C. Hydrogen Bond 2.Termination of translation takes place when the ribosome reaches: A. A primer B. The promoter C. The start codon D. A stop codon 3. Which of the following is Different between prokaryotic and eukaryotic translation? A. tRNA brings amino acids to the ribosome B. Codon is complementary to anticodon C. Coding dictionary D. Occurs in same place as...

Does all Nonpolar amino acids have the same titration curve?

Subjects