Calculate the pI of the peptide KLMRDSP (pKa = 3.5, 3.9, 9.5, 10.0, 12.5).

Enter an estimate for the charge on the peptide KPIVRFDEESC at pH 8.0.

At which pH would the peptide with the amino acid sequence 'KEYHR' be found in an IPG (Immobilized pH gradient) strip after successful isoelectric focusing. Show calculation. lonizable groups Alpha amine group of K Side chain group of K Side chain group of E Side chain group of Y Side chain group of H Side chain group of R Alpha carboxylic acid group of R pka 8.95 10.53 4.25 10.07 6 12.48 2.17

The hexapeptide Ala-Met-Leu-Lys-Phe-Asp is digested in the same tube with both Cyanogen Bromide and Trypsin at the same time at pH=7. Draw the structure of the product(s) that would bind to a cation exchange column. (Relevant pKa values are 2.2, 3.9, 9.5 and 10.5. Assume pKa values for any newly generated a-amino and a-carboxyl groups are 9.5 and 2.2 respectively)

Please draw titration curves for peptide HFDTYA and HEKDGQ, and calculate the pl for each. Usethis information to explain why the peptide HFDTYA has low solubility and HEKDGQ has a highersolubility in bulk water at pH = 7.

you have the following peptide Arg-Ile-Pro-Leu-Asp-Lys-Glu The net charge on this peptide at pH 7.0 is ?. The net charge on this peptide at 1M HCl is ?.

After staining an SDS-PAGE gel with Coomassie Blue G-250, the protein bands are visualized by de-staining the gel in a Coomassie Blue G-250 de-staining solution. This solution is made up of 10% acetic acid, 50% methanol, and 40% distilled water. How much of each of these components do you need to prepare 5 liters of Coomassie Blue G-250 de-staining solution?

Which of the peptide sequences below best matches the hydropathy plot shown? L 10 Residue Number 4 2 Hydropathy value -2 0 セー RAFLILFMTYFLILFLI ILYYAGSREDHSGYLIL OLHGDQNRERDGHSQERD EQSDTERNQHGALIYLI 01 5 15

Calculate the isoelectric point (pl) of the oligo peptide PEPTIDE. Ans=3

1) Indicate the total charge of the peptide at pH 7.0, 9.0, and 11.0 2) Determine the isoelectric point (pI) for this peptide. Show the relevant pKa’s and your calculation.  3) What is the fraction of the peptide that has the N-terminal amino group deprotonated at pH 9.