b).paacanendt... prooic amino actd residues womin 22) consider the following two
ID: 213032 • Letter: B
Question
b).paacanendt... prooic amino actd residues womin 22) consider the following two peptides i LKAENDEAARAMSEA i) CRAd6FwDaPGTSN a) Which of the above peptides will likely form an a-helical structure and why? LKAENDEAARAmSER wil most form an a smucrwe becaus)contains prolire ard qluart wnich helix brea ars arol presenc. of neix orcoers i miro accol es spirals to rardon coius eterded stretarcs, or boerds promotts e sneet Which of the péptides will migrate faster using cation-exchange chromatography, why? b) c) Which of the peptides can give an absorbance in the UV spectroscopy at 275 nm, why? d) Can any of these peptides form a disulfide linkage? which one? whyExplanation / Answer
LKAENDEAARAMSEA sequence is Leucine-Lysine-Alanine-Glutamic acid-Asparagine-Aspartic acid-Glutamic acid-Alanine-Alanine-Arginine-Alanine-Methionine-Serine-Glutamic acid-Alanine.
CRAGGFPWDQPGTSN sequence is Cystine-Arginine-Alanine-Glycine-Glycine-Phenylalanine-Proline-Tryptophan-Aspartic acid-Glutamine-Proline-Glycine-Threonine-Serine-Asparagine.
In a Cation-Exchange Chromatography the peptide with sequence LKAENDEAARAMSEA will move slower in comparison with peptide of sequence CRAGGFPWDQPGTSN. This so because LKAENDEAARAMSEA contains two positively charged amino acids i.e.Lysine and Arginine and CRAGGFPWDQPGTSN contains one positively charged amino acid i.e. only Arginine. So the peptide with more number of positively charged amino acids will move slower in comparison with peptide with less number of positive amino acid, as that peptide of more positive amino acid will bind to negatively charged beads of the chromatography column more tightly.
Neither of the two peptide will have a disulphide bond in their structure because none of them have two cysteine amino acid in their primary sequence which is required for the formation of disulphide bond.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.