Rational design of a thermostable esterase for the production of highvalue bioplastics for biomedical applications


This project is focused on the design of customized thermostable enzymes to produce highvalue
biopolymers for biomedical
We are living a new industrial production paradigm era, where biocatalysis is becoming increasingly competitive and replacing
traditional chemical synthesis. Nowadays, we can produce molecules of interest in a sustainable and green manner, contributing to
a circular economy. That is achieved by unlocking the power of enzymes, nature catalysts, using microbial strains or in cellfree
systems. Enzymes can operate under mild conditions, do not require toxic solvents and are specific. Thus, producing less side
products. However, wildtype
enzymes have limitations, such as low stability or low activity for the required products, which often
make them unsuitable for relevant industrial applications. Rational enzyme design studies, at the nanoscale the enzyme’s structure
and catalytic mechanisms with the goal of designing a bespoked
enzyme variant for each molecule of interest at a fraction of the
time and cost associated with traditional protocols, like directed evolution.
In this project we will design bespoke enzymes to produce biopolymers, which are a green alternative to the fossil resources derived
plastics. The market value for renewable plastics is expected to reach $5.4 billion in 2030 [1]. The capacity production will triple
from just 5.7 million tons in 2014 to 17 million tons in 2020 [2]. The challenge is not just the replacement of fossil fuel derived
polymers by costeffective
biosynthetic routes but also obtaining higher value polymers for new applications, such as biomaterials.
Portugal has an important cluster of industries that either produce or rely on plastics. A particularly important cluster is the
“Engineering and Tooling” that identifies health as an important target market for their products. In fact, the market for
regenerative implantation surgeries, therapeutic cell culturing and tissue repair is expected to reach US $94.2 billion by the end of
2025 [3]. Research on highvalue
polyester enzymatic synthesis for biomedical applications is thus strategic for Portugal’s industrial
The consortium for this project combines expertize in: 1) Rational enzyme design, an emergent field that is revolutionizing
biocatalysis by allowing to obtain enzymes with better activities, selectivities and stability [4]? 2) wet lab validation of the designed
enzyme variants? 3) structural and thermal characterization of the obtained biomaterials.
The objective is to produce Poly(?caprolactone)
(PCL) and PCLpolyethylene
glycol (PEG) c opolymer, widely used polyesters in
biomedical applications [5], using a highly thermostable redesigned esterase variant with enhanced catalytic activity. This will allow
circumventing the current industrial challenges associated with the use of commercial lipases in a costeffective
The in silico design will comprise the study of the catalytic mechanisms of a thermostable esterase and of the most used c ommercial
lipase (Candida antartica lipase B CALB),
using our own protocol. This involves employing stateoftheart
computational methods,
such as molecular dynamics simulations (MD) and quantum mechanics/molecular mechanics methods (QM/MM) [4]. Substrates
binding and TS stabilization will be characterized for the enzymes. The designed enzyme variants will be tested in the wet lab for
(co)polymers conversion. The obtained polymers will be characterized by structural and thermal analysis
(Attenuated total reflectance Fourier transform infrared spectroscopy (ATRFTIR),
nuclear magnetic resonance (1H, 13C NMR), XRay
diffraction, sizeexclusion
chromatography (SEC), differential scanning calorimetry (DSC) and thermogravimetric analysis
Lipases and esterases industrial market is on the rise. The projected market share for lipases alone is US$ 345 million for 2017 [6].
The design of new industrial enzymes will contribute to place Portugal in the forefront of the new bioeconomy.

Main Local Researcher

Andreia Fernandes de Sousa




Universidade de Aveiro



Share this Project:

Related Projects

We use cookies for marketing activities and to offer you a better experience. By clicking “Accept Cookies” you agree with our cookie policy. Read about how we use cookies by clicking "Privacy and Cookie Policy".