Abstract: Aspects of the disclosure relate to Botulinum toxin X (BoNT X) protein variants (e.g., BoNT X protease variants). The variants provided herein have been evolved to cleave procaspase-1. Some of the variants provided herein do not cleave the native substrate of BoNT X protease, VAMP1 protein. Further aspects of the disclosure relate to nucleic acids encoding the procaspase-1 cleaving polypeptides described herein and expression vectors comprising the nucleic acids, as well as host cells and fusion proteins comprising the procaspase-1 cleaving polypeptides described herein and kits comprising the procaspase-1 cleaving polypeptides, nucleic acids, fusion proteins, expression vectors, or host cells described herein. Further aspects of the disclosure relate to methods of producing BoNT X protein variants (e.g., BoNT X protease variants) and methods of using the BoNT X protein variants (e.g., BoNT X protease variants), for example, to induce cell death.

Abstract: The disclosure provides amino acid sequence variants of Botulinum neurotoxin (BoNT) proteases that cleave (VAMP1, VAMP2, VAMP7, VAMP8, SNAP25, SNAP23, PTEN, etc.) and methods of evolving the same. In some embodiments, proteases described by the disclosure are useful for cleaving proteins found in a cell, that is in an intracellular environment. In some embodiments, proteases described by the disclosure are useful for treating diseases associated with increased or aberrant VAMP7, VAMP8, SNAP23 or PTEN expression or activity, for example, cancer and neurological disorders. Some aspects of this disclosure provide methods for generating BoNT protease variants by continuous directed evolution.

Abstract: The disclosure provides fusion proteins comprising a pleckstrin homology (PH) domain and a variant of Botulinum neurotoxin E (BoNT E) protease that cleaves certain non-canonical protein targets (e.g., PTEN). Fusion proteins described in the disclosure are useful for cleaving target proteins found in a cell, that is, in an intracellular environment. Aspects of the disclosure provide methods for inhibiting PTEN amount, activity, or function in a cell or subject, the methods comprising administering to a call or subject a fusion protein described herein.

Abstract: The disclosure provides amino acid sequence variants of Botulinum neurotoxin F (BoNT F) proteases that cleave SNARE proteins (e.g., VAMP1, VAMP7, etc.) and methods of evolving the same. In some embodiments, proteases described by the disclosure are useful for cleaving proteins found in a cell, that is in an intracellular environment. In some embodiments, proteases described by the disclosure are useful for treating diseases associated with increased or aberrant VAMP7 expression or activity, for example, cancer, transplantation rejection, graft-versus-host disease, and neurological disorders. Some aspects of this disclosure provide methods for generating BoNT protease variants by continuous directed evolution.

Abstract: The disclosure provides amino acid sequence variants of Botulinum neurotoxin (BoNT) proteases that cleave (VAMP1, VAMP2, VAMP7, VAMP8, SNAP25, SNAP23, PTEN, etc.) and methods of evolving the same. In some embodiments, proteases described by the disclosure are useful for cleaving proteins found in a cell, that is in an intracellular environment. In some embodiments, proteases described by the disclosure are useful for treating diseases associated with increased or aberrant VAMP7, VAMP8, SNAP23 or PTEN expression or activity, for example, cancer and neurological disorders. Some aspects of this disclosure provide methods for generating BoNT protease variants by continuous directed evolution.