Conformational Selection in Enzyme-Catalyzed Depolymerization of Bio-based Polyesters

• Enzymatic degradation of synthetic polymers holds promise for advancing towards a bio-based economy. However, the bulky nature of polymers presents challenges in accessibility for biocatalysts, hindering depolymerization reactions. Beyond the impact of crystallinity, polymer chains can reside in different conformations affecting binding efficiency to the enzyme active site. We previously showed that the gauche and trans chain conformers associated with crystalline and amorphous regions of the synthetic polyester polyethylene terephthalate (PET) display different affinity to PETase, thus affecting the depolymerization rate. However, structural-function relationships for biopolymers remains poorly understood in biocatalysis. In this study, we synthetized four bio-based polyesters with different properties by co-polymerizing the same rigid bicyclic terpene-derived diol with various dimethylesters spanning from semi-aromatic to aliphatic chains of varying length, and subjected them to enzymatic degradation reactions in concert with induced-fit docking (IFD) analyses- x. Our findings demonstrate the importance of conformational selection for biopolymers in which the simple 1-dimensional geometric parameter with respect to how the polymeric chain is folded into either a straight or twisted conformation has a crucial role in biocatalytic degradation by showing different affinities to enzyme ground state conformers. This work highlights how matching substrate and enzyme conformations needs to be considered to optimize degradation efficiency of biopolymers, providing valuable insights for the development of sustainable bioprocesses in polymer degradation.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Industriell bioteknik -- Biokatalys och enzymteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Industrial Biotechnology -- Biocatalysis and Enzyme Technology (hsv//eng)

Keyword

Biocatalysis

bio-based polymers

FDCA

pinene

conformational selection

enzymatic degradation.

Publication and Content Type

vet (subject category)

ovr (subject category)