Question

Which of the following amino acids might be found on the surface of a transmembrane protein, in the region contacting the fatty acyl chains (ie in the middle of the membrane)?

a. N,Q,V,E
b. S,D,R,K
c. T,L,M,I
d. H,F,W,Y

Answer 1

The amino acids Threonine (T), Leucine (L), Methionine (M), and Isoleucine (I) are non-polar and hydrophobic, suitable for positioning within the hydrophobic region of a transmembrane protein that makes contact with the fatty acyl chains of the lipid bilayer. c. T,L,M,I

Step-by-step explanation:

The question involves identifying which amino acids you would expect to find in the region of a transmembrane protein that contacts the hydrophobic core of the lipid bilayer. The interior of a lipid bilayer is made up of fatty acyl chains, which create a hydrophobic environment. Amino acids within transmembrane regions that interact with these fatty acyl chains would typically be those that are non-polar and hydrophobic as well, allowing them to integrate with the membrane without disrupting its structure.

The correct group of amino acids from the options provided that you would expect to find in the interior of a transmembrane protein is T, L, M, I. This option comprises Threonine (T), Leucine (L), Methionine (M), and Isoleucine (I), all of which are non-polar and hydrophobic, suitable for embedding within the lipid bilayer. In contrast, polar and charged amino acids, such as serine (S), aspartic acid (D), arginine (R), and lysine (K), would typically be found on the aqueous-facing surfaces of membrane proteins or within the interior of soluble proteins where they can interact with water.