Which of the following peptide fragments would you expect to find buried in the center of a water soluble protein? Explain your answer.

a) DEGKRGDK
b) ALVWIFLF

To determine which of the given peptide fragments would be more likely to be buried in the center of a water-soluble protein, we need to consider their physicochemical properties.

Proteins have a globular structure, with a hydrophobic core and hydrophilic surface. In water-soluble proteins, the hydrophilic residues are generally found on the protein's surface, interacting with the surrounding water molecules, while hydrophobic residues tend to be buried within the protein, shielded from the aqueous environment.

Now, let's analyze the given peptide fragments:
a) DEGKRGDK
b) ALVWIFLF

In peptide fragment (a) DEGKRGDK, we can observe a mixture of both hydrophilic (D, E, and K) and hydrophobic (G and R) residues. However, the presence of hydrophilic residues suggests that this peptide fragment is more likely to be located on the protein's surface, interacting with water molecules rather than being buried in the protein's core.

On the other hand, peptide fragment (b) ALVWIFLF consists primarily of hydrophobic residues (A, L, V, W, F). This composition suggests that this peptide fragment is more likely to be found buried within the hydrophobic core of a water-soluble protein.

In summary, based on the analysis of their physicochemical properties, peptide fragment (b) ALVWIFLF is more likely to be buried in the center of a water-soluble protein, while peptide fragment (a) DEGKRGDK is more likely to be located on the protein's surface.