Discuss and compare the potential contributions for tertiary structure in a protein for the side chain of histidine at each of the following pH values: pH 3, pH 7 and pH 10. (pKa of R group = 6.5). Mathematically describe (show work) and use a full paragraph when discussing each pH (reminder: grammar and spelling will be graded.

The β-sheet structure is the secondary structure of the protein which is a sideways folded structure of the polypeptide Draw the symbol of the β-sheet structure and Name 2 types of β-sheet and explain the difference

Among these amino acid combinations listed above, only the combination of Lys and Glu have side chains with groups that have the greatest ability to stabilize the tertiary structure of a protein.   Explain by drawing (a) why Lys and Glu side chain interaction stabilizes the tertiary structure of a protein (b) why the pairs of Glu and Asp & Arg and Pro cannot provide the stability to the protein structure.

Protein-4YU4 is given, choose a part of it (containing at least 30 amino acid residues), find the amino acid sequence (sequence in it), identify what functional groups the amino acid substitutes contain (carboxyl group and 2-position the Nitro group will form amide bonds, forming the covalent basic structure of the protein). What different interactions can occur between these functional groups? How will it relate to the spatial structure of the protein?

Draw the structure of peptide with the following amino acids Gly-Leu-Ala-Gly-Pro-Hyp. The structure formed of the peptide is most likely a? Please explain.  Thank you!

Currently, aspartic acid is forming an ionic interaction with arginine in a protein. Part a) If arginine is replaced with glutamic acid, would the ionic interaction have its stability increased, decreased, or have no effect on the ionic interaction? Part b) If arginine is replaced with Lysine, would the ionic interaction have its stability increased, decreased, or have no effect on the ionic interaction? Part c) If arginine is replaced with isoleucine, would the ionic interaction have its stability increased, decreased, or have no effect on the ionic interaction?

Considering the chemical characteristics of the amino acids valine and glutamic acid (see Figure 5.14), propose a possible explanation for the dramatic effect on protein function that occurs when valine is substituted for glutamic acid.

say you have been asked to determine the molecular structure of a soluble protein with roughly 500 amino acids per subunit. you think there may be a lysine and aspartic acid interaction so but you want to get molecular conformation. what structural technique would you utilize in order to picture this interaction and what resolution would be needed?

Remembering that the amino acid side chains projecting from each polypeptide backbone in a β sheet point alternately above and below the plane of the sheet, consider the following protein sequence: Leu-Lys-Val-Asp-Ile-Ser-Leu-Arg- Leu-Lys-Ile-Arg-Phe-Glu. Do you find anything remarkable about the arrangement of the amino acids in this sequence when incorporated into a β sheet? Can you make any predictions as to how the β sheet might be arranged in a protein?

Calculate the pI for the following peptide: Phe-Lys-Glu-Asp-Lys-Ser-Ala (note: there is only one alpha carboxyl at the C terminus and one alpha amino group at the N terminus and don't forget to take into account the ionizable side chain groups)