Biocatalysis: Harnessing the Power of the Enzymes

“Enzymes are in many ways the most powerful of the catalysts. Life on this planet is

possible thanks to the presence of a multitude of enzymes evolved by nature to be

perfectly efficient and to allow for very selective transformations. The idea behind

biocatalysis is to make use of these reactions to perform industrially relevant

transformations.”

I have a little confession to make: I might have stolen this quote from the very first lines of my Ph.D. thesis. However, since it is my thesis, and I will not get offended, I guess that there is nothing wrong in doing so.

I have always liked this sentence because I believe it embraces in full the beauty and power of enzymes and their potential in biocatalysis. In this post, I would like to try and share a little of my passion for this field with you.

Protein and enzymes: what are they?

As mentioned in my Ribo-T post (here), proteins are very big molecules (namely macromolecules) that can be found in every living organism and that carry out several fundamental functions. Some are structural components; others can be used for storage, transport, as antibodies, as messengers and catalysts for chemical reactions.

In the latter case, when a protein catalyzes a reaction, it is called enzyme. To catalyze a reaction means to use a catalyst (a helper) to transform a reagent (A) into a product (B). In classical organic chemistry the helper can be a synthetic catalyst; in nature it is an enzyme. Different and specific enzymes are involved in every single process that happens in our body. Without their help, we simply could not function. Nature has evolved so to design a perfect catalyst for every metabolic process (involving a sequence of several chemical reactions) in every living creature.

Biocatalysis

Following up from what I just mentioned, nature is basically offering us a complete set of enzymes (many of which we don’t either know the existence of, yet). Let us not forget that these same enzymes have had millions of years to undergo evolution and to become excellent at what they do.

With the advance of biotechnology, it is nowadays easy to have access to good amounts of these natural catalysts, and this is the reason chemists have started to see the potential of using enzymes in their laboratories. Instead of using a synthetic catalyst to transform (A) into (B), researchers can now use enzymes “easily” produced in-house. This is in brief what biocatalysis is all about: find enzymes to use as biocatalysts for organic chemistry reactions.

Interdisciplinarity is key

Biocatalysis is possible thanks to the modern interdisciplinary scientific spirit. Chemists, biochemists, crystallographers, enzymologists, biotechnologists, computational scientists, molecular biologists (just to name a few) frequently get together to solve different aspects of a biocatalytic problem. Furthermore, thanks to this kind of attitude, it is possible to engineer the natural enzyme (which is generally referred to as wild-type) to make it even better: more specific, more versatile, more active or more stable, depending on the needs.

The advantages of biocatalysis over classical catalysis

Biocatalysis is very interesting both from an industrial and an academic point of view.

Enzymes catalysis requires milder conditions compared to chemical catalysis: the reactions can take place for example in an aqueous environment instead than in organic solvents, and lower temperature and pressure are generally required. Enzymes are biodegradable and non–hazardous material. They also tend to be more selective than chemical catalysts, and this is all very in line with green chemistry and an environmentally friendly attitude. The chemical industry understood this, and it is transitioning towards this promising alternative.From an academic point of view, the study of enzymes to produce better catalysts, allows to shed light on basic questions about protein evolution and enzyme mechanisms, advancing our knowledge needed to unravel the complexity of nature.

This is only a very brief summary of what biocatalysis is and what it can do. There is so much more to it and I am planning to write more specific posts in the future. Biocatalysis is a young field of study, but It is developing remarkably quickly as an instrument towards a much greener and sustainable world. In the hope to have stimulated your attention, stay tuned to find out more!

If you are interested in reading more, here are some interesting text-books:

• Faber, Biotransformations in Organic Chemistry, 6th ed., Springer-Verlag, Berlin, 2011.
• Bommarius and R. B. Riebel-Bommarius, Biocatalysis: Fundamentals and Applications, Wiley-VCH, 2004.