Alzheimers disease is associated with aggregation of amyloid

Alzheimer\'s disease is associated with aggregation of amyloid proteins. A 42-amino-acid peptide may be involved in this aggregation. The last few residues of this peptide are immersed in the cell membrane. Based on your knowledge about membrane proteins, which of the following sequences most probably identifies the last four amino acids in this 42-amino-acid peptide?

A

Gly-Asp-Tyr-Lys

B

Val-Val-Ile-Ala

C

Met-Lys-Tyr-His

D

Asp-His-Ser-Arg

Please explain your reasoning.

Solution

B. Val-Val-Ile-Ala

Basically the amino acid reside inside the cell membrane must be hydrophobic. so the peptide B is the correct where all four amino acids are hydrophobic.