Engineering a Lys-Asn isopeptide bond into an immunoglobulin-like protein domain enhances its stability.

ABSTRACT: The overall stability of globular protein structures is marginal, a balance between large numbers of stabilizing non-covalent interactions and a destabilizing entropic term. Higher stability can be engineered by introduction of disulfide bonds, provided the redox environment is controlled. The discovery of stabilizing isopeptide bond crosslinks, formed spontaneously between lysine and asparagine (or aspartic acid) side chains in certain bacterial cell-surface proteins suggests that such bonds could be introduced by protein engineering as an alternative protein stabilization strategy. We report the first example of an isopeptide bond engineered de novo into an immunoglobulin-like protein, the minor pilin FctB from Streptococcus pyogenes. Four mutations were sufficient; lysine, asparagine an

SUBMITTER: Kwon H 

PROVIDER: S-EPMC5311914 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature