De novo design of integral membrane proteins.

We have designed integral membrane proteins with one, two and four hydrophobic transmembrane segments of highly simplified amino acid composition and with appropriately placed positively charged lysine residues intended to control the overall membrane orientation. When expressed in Escherichia coli, these model proteins insert efficiently into the inner membrane and adopt the predicted topologies. This demonstrates the feasibility of de novo design of multi-spanning integral membrane proteins, and opens up new possibilities for membrane protein engineering.