Transmembrane β-barrel proteins (TMBs) are of great interest for
single-molecule analytical technologies because they can spontaneously fold and
insert into membranes and form stable pores, but the range of pore properties that
can be achieved by repurposing natural TMBs is limited. We leverage the power of
de novo computational design coupled with a “hypothesis, design, and test”
approach to determine TMB design principles, notably, the importance of negative
design to slow β-sheet assembly. We design new eight-stranded TMBs, with no
homology to known TMBs, that insert and fold reversibly into synthetic lipid
membranes and have nuclear magnetic resonance and x-ray crystal structures very
similar to the computational models. These advances should enable the custom
design of pores for a wide range of applications.
Boosting protein stability with the computational design of β-sheet surfaces