Title: Synergistic effect of mutagenesis and truncation to improve a polyesterase from Clostridium botulinum for polyester hydrolysis Biundo A, Reich J, Ribitsch D, Guebitz GM Ref: Sci Rep, 8:3745, 2018 : PubMed
The activity of the esterase (Cbotu_EstA) from Clostridium botulinum on the polyester poly(ethylene terephthalate) (PET) was improved by concomitant engineering of two different domains. On the one hand, the zinc-binding domain present in Cbotu_EstA was subjected to site-directed mutagenesis. On the other hand, a specific domain consisting of 71 amino acids at the N-terminus of the enzyme was deleted. Interestingly, a combination of substitution of residues present in the zinc-binding domain (e.g. S199A) synergistically increased the activity of the enzyme on PET seven fold when combined to the truncation of 71 amino acids at the N-terminus of the enzyme only. Overall, when compared to the native enzyme, the combination of truncation and substitutions in the zinc-binding domain lead to a 50-fold activity improvement. Moreover, analysis of the kinetic parameters of the Cbotu_EstA variants indicated a clear shift of activity from water soluble (i.e. para-nitrophenyl butyrate) to insoluble polymeric substrates. These results evidently show that the interaction with non-natural polymeric substrates provides targets for enzyme engineering.
Biundo A, Reich J, Ribitsch D, Guebitz GM (2018) Synergistic effect of mutagenesis and truncation to improve a polyesterase from Clostridium botulinum for polyester hydrolysis Sci Rep8: 3745