Enhanced degradation activity of PET plastics by fusion protein of anchor peptide LCI and Thermobifida fusca cutinase

Abstract

The substantial accumulation of polyethylene terephthalate (PET) plastic waste in the environment has exacerbated the issue of plastic pollution. The biodegradation of PET plastics using biological enzymes has garnered considerable attention due to its efficiency and environmentally friendly nature. Nevertheless, the low binding affinity of PET plastics presents a significant limitation to the application of biocatalysts in their degradation. This study endeavors to engineer a fusion protein comprising the anchor peptide LCI, derived from Bacillus subtilis A014, and a thermally stabilized variant of Thermobifida fusca cutinase, D204C/E253C (Tfuc2), with the objective of augmenting its polyethylene terephthalate (PET) degradation efficacy. The findings demonstrate that LCI exhibits a high binding affinity for PET, and the hydrolytic efficiency of the LCI-containing fusion protein is enhanced by a factor of 1.8-34.5 compared to the free Tfuc2 enzyme. The enzymatic characteristics and molecular dynamics simulation outcomes indicate that the improved hydrolytic efficiency of PET may originate from the flexible oscillatory behavior of LCI, which exhibits a high binding affinity for PET. This study presents a novel methodology for the enzymatic degradation of PET plastic waste.

Keywords: Anchor peptide; Cutinase; Enzymatic degradation; Polyethylene terephthalate.