Question

Why are beta-sheets more commonly found in the hydrophobic interiors of proteins rather than on the proteins surfaces?

Answer 1

Beta pleated structure can exist mostly in the interior portion of a protein, because for a beta pleated structure bonding between two adjacent sheets is necessary, which is only possible if the hydrophobic residues of the protein come closer and bind themselves together.

Since in aqueous solutions the hydrophobic portion cannot remain exposed to water because of the unfavorable interactions, so the hydrophobic portion inevitably goes into the protein core where it finds stable interactions with other hydrophobic portions, thus allowing for the beta pleated structure to develop.

Hope this helps !