Question

Lysine has pKa values as illustrated on the diagram below a) H3N ОН рК, 2.18 NH3 pKa 10.53 + рка, 8.95 Calculate the isoelectric point for lysine i) Draw the predominant structure of lysine at pH>12 i b) The amino acid Tyrosine can be used in automated peptide synthesisers but this requires protected forms of the amino acid H2N ОН Он Tyrosine Show how you can synthesise N-protected and C-protected serine derivatives i) ii Show schematically a method to couple the protected serine derivatives to give a Tyr-Tyr dipeptide iShow how protecting groups can be removed. For the following peptide, indicate which bonds are cleaved by trypsin and which are cleaved by c) chyomotrypsin? Briefly explain how you would then sequence the full peptide from the cleaved sequences Phe-Leu-Met-Lys-Tyr-Asp-Gly-Gly-Arg-Val-Ile-Pro-Tyr

Answer 1

r0-53 t 8.95 ali) Jsoalect'e po in (P chnic 2- 19.48 9.74 2 (i) At pH 7 12 -0 NH2 NH2