WHY ENZYMES HAVE NEVER BEEN MORE IMPORTANT

From digesting the food we eat to releasing the energy we need to move, enzymes play countless fundamental roles in our everyday lives. However, the function of these biological catalysts is certainly not limited to our bodies, or even other living organisms; in fact, humans have been harnessing the power of enzymes to carry out both intracellular and extracellular processes for a large part of history. As time goes on, there is no doubt that these biological catalysts will grow in importance, helping us tackle worldwide concerns such as climate change and life-threatening medical conditions.

The first record we have of voluntary enzyme use traces back to over 7,000 years ago. By extracting a mixture of enzymes from the stomachs of goats, sheep and cows, and adding this to milk, people many millennia ago were able to (unknowingly!) catalyse the curdling process used to create cheese. The key enzyme in this mixture is called chymosin: binding to the protein k-casein in milk, chymosin acts as a pair of ‘molecular scissors’ It is the clipping action of this enzyme that causes the milk to curdle.

For lactose intolerant people, who make up 70% of the global population, enzymes are what facilitate the consumption of dairy products. Usually, the enzyme lactase is what breaks down lactose into glucose and galactose, two monosaccharides which can then be absorbed individually into the small intestine with no discomfort. However, lactose intolerant people have low/negligible levels of lactase, meaning the lactose molecules are not broken down until they reach the large intestine, where gut bacteria digest them As a side effect of the bacteria’s activity, some people will get painful symptoms such as bloating. To solve this problem, before selling dairy products, food companies break lactose down into glucose and galactose using extracellular lactase- this allows intolerant people to sustain their calcium and protein intake without experiencing side effects.

DR DOLPHIN: THE HUMAN BODY

The use of enzymes is not limited to the food industry. Januvia, also known as Sitagliptin, is a drug used to treat type 2 diabetes, and is made partially with enzymes Type 2 diabetes occurs when the body is unable to make enough insulin (the enzyme that converts glucose to glycogen), causing high blood sugar levels, or hypoglycemia. Sitagliptin, in part synthesised by coupled enzyme reactions, treats this by increasing the amount of insulin enzyme that your body produces.

Some disorders are caused by a single enzyme working improperly in the body An example of this would be Phenylketonuria, otherwise known as PKU, which is caused by a change in the phenylalanine hydroxylase (PAH) gene This gene helps create the enzyme needed to break down/ metabolise phenylalanine, one of the 20 common amino acids. People with PKU who ingest this amino acid can be subject to permanent intellectual disabilities as phenylalanine builds up in their blood and brain, causing severe damage This disorder is rendered all the more problematic by the fact that phenylalanine is present in poultry, seafood, nuts, dairy and eggs. Fortunately, new enzymes may enable people with PKU to eat whatever foods they wish; in fact, the FDA (Food and Drug Administration) recently approved Palynziq, a novel enzyme therapy which contains pegvaliase, a bacterial enzyme that can break down phenylalanine

Enzymes have also begun to be used to solve environmental issues such as climate change Recently, bacteria which produce plastic-degrading enzymes were discovered Efforts are already under way to produce improved versions of these enzymes, as these may then enable us to start breaking down the millions of tonnes of plastic going to waste in the world. At the same time, there are also enzymes that have been discovered and are being optimised to produce non-petroleum derived biodegradable plastic, which could give us a much more sustainable production pathway for this material and help us reduce the issue of plastic pollution.

There are many other environmental problems which could be solved by enzymes. Currently, 90% of the energy consumption of laundry machines is due to the water heating systems, which play a crucial role in the removal of stains on fabric Washing in cold water by using enzymes to break stains down instead of heat would save 32 million metric tonnes of carbon dioxide each year, the equivalent of the CO2 emitted by 6.3 million cars.

As the years go on and biotechnologies improve, there is no doubt that the role of enzymes will keep expanding, and that their importance will continue to grow in a multitude of different sectors