(a) Where would cyanogen tromide deave each pegtide? To arower this. provide the single lether sequence for al tragments oblained with cyanogen tremide cleavage lor each peptide. [3 marks] (b) Where would trpein cleave each pepbie? To arseer this, provide fie shile letier sequence for at fragmenti ebtained with typelin cieavage for ench peptide- [3 imarks] (c) You atiempt so subject each peptide to Edman degradation condtions. Bieby (1 sentence). describe the frat step of Edman degadabon [t mark] Can Edman degradation be used to debermine the struchuce of tach pepbide (yes or no) [1 mark]? Explain why you answered yes or no for tach pepode and une struchures to suppert your atawess [3 marks]. (d) For Peptide 1, why is there a "kink" or "bend" in the backbone structure [1 mark]? What is missing from the primary structure of Peptide 1 (Note: It is not related to pH or pKa's) [1 mark]? Redraw the correct structure of this peptide using the 3-letter amino acid code [2 marks]. What reagent would you use to convert the structure you drew into the structure provided above for peptide 1 [ 1 mark]? Would obtaining Mass spectrometry data of Peptide 1 (parent mass and both B and Y fragment ions) be sufficient to confidently assign the sequence of this peptide? Justify your answer [ 2 marks]. (e) For the proline residue in Peptide 3, would a phi angle of 120 and psi angle of +120 be favoured? Explain why or why not. If not, suggest an angle that would be favoured. [3 marks] (a) Where would cyanogen tromide deave each pegtide? To arower this. provide the single lether sequence for al tragments oblained with cyanogen tremide cleavage lor each peptide. [3 marks] (b) Where would trpein cleave each pepbie? To arseer this, provide fie shile letier sequence for at fragmenti ebtained with typelin cieavage for ench peptide- [3 imarks] (c) You atiempt so subject each peptide to Edman degradation condtions. Bieby (1 sentence). describe the frat step of Edman degadabon [t mark] Can Edman degradation be used to debermine the struchuce of tach pepbide (yes or no) [1 mark]? Explain why you answered yes or no for tach pepode and une struchures to suppert your atawess [3 marks]. (d) For Peptide 1, why is there a "kink" or "bend" in the backbone structure [1 mark]? What is missing from the primary structure of Peptide 1 (Note: It is not related to pH or pKa's) [1 mark]? Redraw the correct structure of this peptide using the 3-letter amino acid code [2 marks]. What reagent would you use to convert the structure you drew into the structure provided above for peptide 1 [ 1 mark]? Would obtaining Mass spectrometry data of Peptide 1 (parent mass and both B and Y fragment ions) be sufficient to confidently assign the sequence of this peptide? Justify your answer [ 2 marks]. (e) For the proline residue in Peptide 3, would a phi angle of 120 and psi angle of +120 be favoured? Explain why or why not. If not, suggest an angle that would be favoured. [3 marks]
