Question

Question #4 (10 points) - Mass spectroscopy Amino Acid Molecular Weight 89 174 133 146 137, 194 Alanine Arginine Aspartic acid Glutamic acid Glycine Lysine Proline Serine Tyrosine Valine 105 384 340 Hidal 146 115 105 181 117 146 Mass/charge (here the charge is -1, so it's just mass) Above is shown a mass spectroscopy for a peptide 5 amino acids long derived from a soluble protein. This 5 amino acid peptide represents a hydrophilic surface part of the protein (this is a hint as to the composition of this peptide). Determine and give the amino acid sequence of this pentapeptide. Show which end is the amino terminus and which is the carboxy terminus. NOTE: (1) for simplicities sake not all possible peaks are shown, though all relevant peaks are. (2) Not all amino acids are listed, but all relevant/necessary amino acids are. (3) The masses given should be less by one loss of H ion to impose a charge on the molecules). To avoid any possible confusion, I left that out.

Answer 1

Amino Acid Molecular Weight Gly Ala Alanine Arginine Aspartic acid Glutamic acid Glycine Lysine Proline Serine Tyrosine Valine 89 174 133 146 75 146 115 His !37, 91 Serios, Lys Ala Gly, 384 Ala Ser 105 891 279 181 Ala 117 N terminal Mass/charge (here the charge is -1, so it's just mass it's just trepiminal

Amino Acid Molecular Weight Gly Ala Alanine Arginine Aspartic acid Glutamic acid Glycine Lysine Proline Serine Tyrosine Valine 89 174 133 146 75 146 115 His !37, 91 Serios, Lys Ala Gly, 384 Ala Ser 105 891 279 181 Ala 117 N terminal Mass/charge (here the charge is -1, so it's just mass it's just trepiminal

Amino Acid Molecular Weight Gly Ala Alanine Arginine Aspartic acid Glutamic acid Glycine Lysine Proline Serine Tyrosine Valine 89 174 133 146 75 146 115 His !37, 91 Serios, Lys Ala Gly, 384 Ala Ser 105 891 279 181 Ala 117 N terminal Mass/charge (here the charge is -1, so it's just mass it's just trepiminal