Abstract: The disclosure provides cage proteins comprising a helical bundle, wherein the cage protein comprises a structural region and a latch region, wherein the latch region comprises one or more target binding polypeptide, wherein the cage protein further comprises a first reporter protein domain, wherein the first reporter protein domain undergoes a detectable change in reporting activity when bound to a second split reporter protein domain, and wherein the structural region interacts with the latch region to prevent solution access to the one or more target binding polypeptide.

Abstract: Polypeptide inhibitors of SARS-COV-2 are disclosed comprising an amino acid sequence at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to the amino acid sequence selected from the group consisting of SEQ ID NOS: 1-17, 19-21, 23-34 and 100-101, and their use for treating and limiting development of SARS-COV-2 infection.