You have been provided a mixture containing four amino acids (Glu, His, Pro and Lys) to...

You have been provided a mixture containing four amino acids (Glu, His, Pro and Lys) to be separated by ion-exchange chromatography using a Dowex 50 cation-exchange, prepared in a loading buffer at pH 2.0. The following solutions are made available:

The amino acid mixture in 0.04M citrate buffer at pH 2.0.
0.04M citrate buffer, pH 4.5
0.04M citrate buffer, pH 8.0
0.04M citrate buffer, pH 10.5

Is complete resolution of all amino acids achieved if the buffers are allowed to elute through the column sequentially from lowest to highest pH? Identify the order of elution and identify any amino acids that may come off the column together if complete resolution is not achieved. Support your response with an explanation.
Assuming the amino acids in the mixture will elute from the column ONLY at a solution pH that is above their respective pI.

Expert Solution

queen_honey_blossom answered 1 year ago

The amino acid sequence of human adrenocorticotropin, a polypeptide hormone, is: Ser-Tyr-Ser-Met-Glu-His-Glu-Arg-Trp-Gly-Lys-Pro-Val-Gly-Lys-Lys-Arg-Arg-Pro-Val-Lys-Val-Tyr-Pro-Asp-Ala-Gly-Glu-Asp-Gln-Ser-Ala-Glu-Ala-Glu-Pro-Leu-Glu-Phe a)What is the appr

The amino acid sequence of human adrenocorticotropin, a polypeptide hormone, is: Ser-Tyr-Ser-Met-Glu-His-Glu-Arg-Trp-Gly-Lys-Pro-Val-Gly-Lys-Lys-Arg-Arg-Pro-Val-Lys-Val-Tyr-Pro-Asp-Ala-Gly-Glu-Asp-Gln-Ser-Ala-Glu-Ala-Glu-Pro-Leu-Glu-Phe a)What is the approximate net charge of this molecule at pH 3? ph 7? ph 9? Assume that the pKs of the terminal -NH3+ and -COOH groups are 7.8 and 3.6, respectively.

Determine which of these four peptides is most likely to become a beta sheet. Met-Leu-Lys-Ala-Ser-Ala-Leu-Glu-Lys-Leu-Ser-Glu Ala-Glu-Met-Leu-Gln-Lys-Arg-Gly-Cys-Gly-Asp-Glu...

Determine which of these four peptides is most likely to become a beta sheet. Met-Leu-Lys-Ala-Ser-Ala-Leu-Glu-Lys-Leu-Ser-Glu Ala-Glu-Met-Leu-Gln-Lys-Arg-Gly-Cys-Gly-Asp-Glu Lys-Thr-Val-Ile-Trp-Pro-Phe-Tyr-Ile-Gln-Ile-Gly Arg-Ser-Tyr-Glu-Gly-Leu-Lys-Arg-Ile-Ala-Glu-Ser I would like help with the question but also I would like to know what makes a peptide more likely to form a beta sheet over and alpha helix and vice versa.

Consider the following peptide: Cys-Arg-Pro-Asp-Thr-Leu-His-Lys-Gln-Glu-His How is the peptide different at pH = 6 and pH...

Consider the following peptide: Cys-Arg-Pro-Asp-Thr-Leu-His-Lys-Gln-Glu-His How is the peptide different at pH = 6 and pH 8? Which of the two pHs would you use to run an ion exchange column, and would you choose anion or cation exchange?

Amino acid analysis of a nonapeptide yielded the following: Gly2, Glu, Met2, Lys, Arg2, Thr (subscript...

Amino acid analysis of a nonapeptide yielded the following: Gly2, Glu, Met2, Lys, Arg2, Thr (subscript 2's indicate two glycines, two methionines, and two arginines). Reaction of the intact nonapeptide with Sanger's reagent yielded FDNB-Arg; incubation with trypsin yielded free Arg, free Glu, a tripeptide, and a tetrapeptide. Reaction of the tripeptide with Sanger's reagent yielded FDNB-Gly, and reaction of the tetrapeptide with Sanger's yielded FDNB-Thr. Incubation of the above tripeptide with carboxypeptidase (identifies the C-terminal amino acid) identified Arg....

Using a cation exchange resin, a mixture of four amino acids, Asp (pKa 3.9), Arg (pKa...

Using a cation exchange resin, a mixture of four amino acids, Asp (pKa 3.9), Arg (pKa 12.5), Ser (pKa 13) and Lys(pKa 10.5) are separated using an elution gradient of increasing NaCl solution. What would be the correct elution sequence? Explain your reasoning. Draw the chromatogram would look like for this mixture if there was twice as much Asp and Arg in the sample than Ser and Lys.

A peptide has the following sequence: A-K-R-H-G-E-E-R (Ala-Lys-Arg-His-Gly-Glu-Glu-Arg). What is the pI for this peptide? You...

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QUESTION 6 Which of the following peptides is most likely an alpha helix? Arg-Ala-Tyr-Pro-Met-Gly-Val-Leu-Ser-Asp Glu-Ala-Tyr-Pro-Met-Gly-Val-Leu-Ser-Lys Glu-Ala-Tyr-Phe-Met-Gln-Val-Leu-Ser-Lys...

QUESTION 6 Which of the following peptides is most likely an alpha helix? Arg-Ala-Tyr-Pro-Met-Gly-Val-Leu-Ser-Asp Glu-Ala-Tyr-Pro-Met-Gly-Val-Leu-Ser-Lys Glu-Ala-Tyr-Phe-Met-Gln-Val-Leu-Ser-Lys Arg-Ala-Tyr-Phe-Met-Gln-Val-Leu-Ser-Asp

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

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suggest how a protein might have been hydrolyzed to give the amino acids. keep in mind...

suggest how a protein might have been hydrolyzed to give the amino acids. keep in mind that this is made from human consumption.

Examine the tripeptide below: Lys-Glu-Asp Calculate the isoelectric point (pI) of this tripeptide. You can assume...

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