peroxicatsPeroxicats [peroxidases as biocatalysts]. Novel and more robust fungal peroxidases as industrial biocatalysts.

[This article is based on the presentation of the Peroxicats FP7 project. Grant agreement nº: KBBE-2010-4-265397. Total budget: 4.3 million €; EC-funding: 3 million €]

Enzymes catalyzing redox reactions (oxidoreductases) represent an environmentally friendly alternative to harsh chemicals in industrial processes that include oxidative transformations for production of chemicals and other value-added products with large markets in developed and emerging economies.

Fungi and other microorganisms provide the wider and more easily exploitable source for oxidative enzymes.

However, the penetration of microbial oxidoreductases in the chemical markets is still low despite the recent discovery of very promising enzymes.

The use of these enzymes as biocatalysts requires tuning their catalytic and operational properties (a type of manipulation that is possible nowadays using protein engineering tools).
Overview of reactions catalyzed by heme-thiolate peroxidases (HTP).

In addition to microbial screening, the huge amount of genomic resources available nowadays, and to be generated during the course of the project, will be exploited in the search for new fungal peroxidase/peroxygenases.

Automatic extraction system. Some of the main issues presently limiting the industrial application of peroxidases will be addressed, such as:
- Their suicide inactivation by H2O2
- Low functional expression
- Limited oxygen transfer potential

Moreover, the catalytic properties of the most interesting enzymes will be modulated to adapt them to the industrial processes.

A combination of rational and non-rational design will be used, based on directed mutagenesis, and random mutagenesis (together with high-throughput screening), respectively.

The reaction mechanisms and industrial interest of the selected peroxidases/ peroxygenases will be studied using modern analytical techniques, including two-dimensional NMR, that are able to provide information on the modifications produced on both simple and complex substrates.

In this way novel and robust peroxidases/peroxygenases will be obtained with high potential both in bulk chemistry, e.g. for hydrocarbon oxyfunctionalization and oxidation of recalcitrant compounds, and fine chemistry, e.g. substituting costly hydroxylation reactions in the pharmaceutical sector.


More info also: a paper published by the Peroxicats project - "Structural Basis of Substrate Conversion in a New Aromatic Peroxygenase"