Question

If a transmembrane protein was in the beta barrel structure, would the side chains sticking out be hydrophobic while the hydrophilic side chains remain shielded by the hydrophilic components?

Answer 1

Yes. The β barrel proteins are abundant in the outer membrane of mitochondria, chloroplasts, and many bacteria. Some are pore-forming proteins, generating water-filled channels that allow selected hydrophilic solutes to cross the lipid bilayer of the bacterial outer membrane.Polar side chains (hydrophilic) line the aqueous channel on the inside, while nonpolar side chains (hydrophobic) project from the outside of the barrel to interact with the hydrophobic core of the lipid bilayer. Loops of polypeptide chain often protrude into the lumen of the channel, narrowing it so that only certain solutes can pass.