Análisis estructural de la enzima PETasa de Ideonella sakaiensis y enzimas homólogas

Abstract

Polyethylene terephthalate (PET), a low-cost thermoplastic produced industrially from fossil raw materials, is massively used in industry, and has become a high-impact pollutant. Among the latest discoveries related to the enzymatic treatment of PET is PETase from I. sakaiensis (IsPETase), which is a hydrolase capable of degrading PET. The present work was elaborated to establish possible mutations and modifications that improve the catalytic activity and enzymatic stability of IsPETase, for which a structural analysis of the same was carried out. Using the UNIPROT and PDBeFOLD databases, the enzymes that share a high degree of homology with IsPETase were identified. From these results, an analysis was carried out based on their percentage of sequence identity and secondary structure identity (SEQ and SSE respectively), E-value, Score, RMSD, and Q. The enzymes of greatest interest were selected for this analysis, the main ones being PbLipaseT, RgPETase, BbHydrolase, and SvCUT190, establishing that the N212S mutation can be used to improve the enzymatic activity and stability, in addition, possible substitutions to be studied were described to evaluate the effect that these would cause in the enzyme (S188E, S188A, and S114H). In the analysis of mutant variants, the presence of different amino acids in each case was identified; therefore, different possible substitutions to be made in the IsPETase enzyme were proposed, among the most relevant ones are W159F and S238T.