If you’ve followed us for a while, you may already know that at ZYMVOL we work primarily with enzymes, designing and optimizing them through computer simulations. Enzymes are applied pretty much everywhere: from food products, cosmetics, in the synthesis of pharmaceutical products, and -as the natural biomolecules they are- even the inside of your own body.

But despite the key importance of these molecules in our daily lives, not many people know what they do! That’s why in this post we want to break down some of the main points regarding enzymes, its industrial uses and why they are the key to a greener, more sustainable chemical industry.

What are enzymes?

Enzymes are proteins naturally found in living organisms. They work as biocatalysts, which means they help “catalyze” or accelerate chemical processes. Instead of waiting hours or even days for the reaction to be completed, enzymes have the power to speed it up and produce many reactions in less than a second!

Take for example the lactase enzyme. When we drink milk, there’s a protein whose sole purpose is to break down lactose so we can digest it better. However, people who are lactose intolerant don’t have that enzyme, or simply  don’t have enough of it, so they have a harder time digesting it (and suffer the consequences of it).

What does an enzyme look like?

There are around 20 different types of amino acids in Nature, and they are crucial in defining an enzyme’s characteristics. An enzyme is made up of a sequence of amino acids, varying greatly on number. Some may just have 50 amino acids, some may have more than 200.

Here, the variability is enormous: proteins can have different lengths, and can be formed only by some of the around 20 available amino acids. That’s why In Nature, there are millions of different proteins, each one with a particular amino acid sequence.

Also, they tend to fold into themselves, that’s why you’ll usually see images of enzymes represented like this:

 

However, the most important thing to know is that an enzyme’s amino acid sequence defines its shape. And its shape determines its function.

How does biocatalysis work?

As we mentioned previously, enzymes’ function is to catalyze chemical reactions. A catalyst is a molecule that increases the rate of a chemical reaction without being consumed by the reaction.

Enzymes catalyze all reactions that take place in living organisms, and these reactions can be of different types, like synthesis or degradation of products, among others.

To understand the process better, take a look at the following image, which represents the most accepted model of enzyme catalysis, the Induced Fit model, representing a synthesis reaction (formation of a product):

The enzyme-catalyzed reaction takes place in an inner region of the enzyme known as “active site”. The molecule that is bound in the active site is the “substrate”. Active sites are very specific, and only react with very specific types of “substrates”.

The “substrate” interacts with the “active site”, forming a transient “enzyme-substrate complex” that becomes an “enzyme-product complex” once the chemical changes take place.

Even if initially the substrate doesn’t adhere perfectly to the active site, the enzyme is flexible enough to adapt to the substrate. When the reaction finishes, the formed product is released and the free enzyme can bond to another substrate, starting the process again.

Examples of enzymes in our daily lives

As mentioned before, enzymes play a very important role by accelerating chemical reactions happening in our bodies, like breaking down lactose.

But this is just one example of the millions of possibilities that exist. Besides very technical uses, scientists have also applied these bio-molecules in the industry to create all kinds of products. Nowadays, they can be found in:

  • Pharmaceutical.
  • Chemical.
  • Food.
  • Animal Feed.
  • Cosmetics.
  • Cleaning.
  • Textile.
  • Recycling.
  • Pulp and paper products.
  • Flavors and Fragrances.

Industrial applications of enzymes

There’s a long history of enzymes being used to elaborate certain goods (for example, with alcohol fermentation) and, in the 20th century, they started to become more present in various industries. However, not all natural enzymes are valid for the overwhelming amount of different and highly specific chemical processes that take place in the current market.

Global trends on consumer needs and social change push companies to improve their products in different aspects, like  composition,  performance  or  manufacturing, while implementing sustainable production processes and reducing costs.

Therefore, protein engineering and enzyme improvement has gained popularity for companies who want to maintain their competitiveness, while also transforming their production to comply with green chemistry standards.

Some of the most popular industrial enzymes include:

  • Alcohol Dehydrogenases. Those that can reduce aldehydes into primary alcohols and ketones into secondary alcohols.
  • Oxidative Enzymes and Oxidoreductases. Those that cause or accelerate an oxidation reaction.
  • Lipases. Those that help disaggregate fat through hydrolysis.

Why enzymes are key for a sustainable future

There’s no denying that one of the biggest challenges the world faces nowadays is tackling climate change, which many environmental experts predict will have terrible consequences in the following decades. It’s no wonder that in 2015, the UN set a list of Sustainable Development Goals, with goals specifically focused on Climate related issues and Responsible Production.

What many people don’t know is that the use of enzymes in an industrial level can make a big difference in the way companies operate, and, therefore, have a significant and positive impact on the environment.

Why is that? Some advantages of using enzymes include:

  • Mild reaction conditions: enzymes usually do not require harsh working conditions such as high temperatures or use of solvents or other hazardous auxiliary chemicals.
  • Eco-friendliness: enzymes can substitute organic catalysts that require heavy metals that eventually are released to the environment.
  • Speed: enzymes are able to carry out chemical reactions in a extremely fast way
  • Efficiency: with proper reaction conditions, enzymes are able to process all present substrate and convert it into desired product
  • High product selectivity: enzymes are able to react with specific, targeted molecules, even in complex mixtures
  • Savings: with the advantages commented above, companies can save resources

Moreover, and according to the OECD, the potential of climate change mitigation coming from biotechnology processes and biobased products (in which improved enzymes applied to the chemical sector are included) “ranges from between 1 billion and 2.5 billion tons CO2 equivalent per year by 2030”.

Enzymes implemented as industrial biocatalysts are paving the way for a green chemistry revolution. As more industries start to embrace their use, we can get closer to reaching a true bioeconomy.

 


References:

Heckmann, C. M.; Paradisi, F. (2020). Looking Back: A Short History of the Discovery of Enzymes and How They Became Powerful Chemical Tools. ChemCatChem, 12(24), 6082-6102.

Lehninger Principles of Biochemistry, 5th Edition. D.L Nelson and M.M Cox (2008)

Neitzel, J. J. (2010) Enzyme Catalysis: The Serine Proteases . Nature Education 3(9):21

Nature Education eBooks chapters Essentials of Cell Biology, Unit 2.4 and Cell Biology for Seminars, Unit 2.4  © 2014 Nature Education https://www.nature.com/scitable/topicpage/protein-structure-14122136/

OECD.(2011). Industrial Biotechnology and Climate Change. Opportunities and Challenges. http://www.oecd.org/science/emerging-tech/49024032.pdf

Phillips, Rob; Milo, Ron; How many reactions do enzymes carry out each second? Cell Biology by the Numbers. http://book.bionumbers.org/how-many-reactions-do-enzymes-carry-out-each-second/