Laboratory evolution of a sortase enzyme that modifies amyloid-β protein.

ABSTRACT: Epitope-specific enzymes are powerful tools for site-specific protein modification but generally require genetic manipulation of the target protein. Here, we describe the laboratory evolution of the bacterial transpeptidase sortase A to recognize the LMVGG sequence in endogenous amyloid-β (Aβ) protein. Using a yeast display selection for covalent bond formation, we evolved a sortase variant that prefers LMVGG substrates from a starting enzyme that prefers LPESG substrates, resulting in a >1,400-fold change in substrate preference. We used this evolved sortase to label endogenous Aβ in human cerebrospinal fluid, enabling the detection of Aβ with sensitivities rivaling those of commercial assays. The evolved sortase can conjugate a hydrophilic peptide to Aβ₄₂, greatly impeding the

SUBMITTER: Podracky CJ 

PROVIDER: S-EPMC7904614 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature