Are you looking to start the next multimillion-pound business? Then let me introduce you to proteins that stimulate cell growth. Currently, they cost several million pounds per gram, making them more expensive than diamonds. If we are going to realise the once dystopian, yet increasingly feasible, vision of “lab-grown” meat, we are going to need more than a couple of grams to make enough filet mignon to feed the masses.

“Several million pounds per gram, making them more expensive than diamonds”

So-called “cultivated” or “lab-grown” meat was initially proposed as food for astronauts but has since turned from a sci-fi fantasy to a source of hope for a more sustainable and animal welfare-conscious future.

Industrial animal agriculture lies at the intersection of some of the most pressing issues facing humanity today: climate change, zoonotic pandemics, antibiotic resistance, biodiversity loss and animal welfare. Although vegetarianism and veganism are becoming more mainstream, global demand for meat continues to rise. But perhaps one of the best ways to bring about seismic change in consumer behaviour could be through the provision of better alternatives.

Cultivated meat is produced from animal cells cultured in a bioreactor, and aims to have the same composition as conventional meat, so is therefore indistinguishable in taste and nutritional profile. The process begins with the animal, but instead of slaughtering it, a simple biopsy (sample of cells) is taken. Then these cells are cultured in large vats, called bioreactors, increasing the cell mass in volume and density to produce a chunk of meat.

Why grow the complex, sentient creatures we call cattle – with bones, hooves, and stomachs belching methane – when we are ultimately only interested in enjoying a medium-rare steak? Cultivating meat in a laboratory eliminates this wastage, bypassing the ethically and environmentally controversial task of growing a whole body and sustaining a consciousness.

Cattle eat 25 calories for every calorie of edible protein they produce. This huge inefficiency explains why animal agriculture uses 77% of agricultural land yet provides only 33% of our protein supply globally. It drives climate change, being responsible for almost 15% of all greenhouse gas emissions. Furthermore, the majority of the world’s antibiotics (73% in 2017) are fed to farm animals to keep them alive in poor conditions where disease spreads easily, contributing to the rising threat of antibiotic resistance.

The case to change our food system is strong and the potential benefits of cultivated meat are considerable. Still, there are major technical hurdles to overcome. One of them is the cost of the nutrient soup the cultured cells grow in: If we feed them diamond-priced growth factors, who would be willing to pay £50 for a burger?

This is where the fine art of “protein origami” can be used to overcome some of these hurdles and help us to sustain our food system long into the future.

Proteins are themselves made of smaller building blocks: the amino acids. There are 20 of them, and like an alphabet, they can be arranged in countless different ways to create the unique “name” of a protein. A typical protein contains over 300 of these “letters” arranged in a supercalifragilisticexpialidocious-style sequence.

Depending on its “name”, the protein folds into a certain shape, creating a 3D structure. It is like origami that transforms a flat square sheet of paper with the protein’s name written on it into a finished protein sculpture. This analogy is not just a fanciful idea; it is a daily reality in lab work, where understanding this “protein origami” can pave the way for making a cultivated meat burger more affordable.

The protein FGF2 (fibroblast growth factor 2) is one of the million-pound growth factors needed to grow meat in the lab. But, unlike a long-lasting diamond, FGF2 is inherently unstable and degrades within seven hours. In other words, the FGF2 origami is what we might call fragile.

“Protein origami can pave the way for making a cultivated meat burger more affordable”

Various startups have set out to change this, as longer-lived FGF2 would increase the lifetime of the nutritious soup required to grow enough cells to produce a lab-grown steak. The maths is easy: the longer FGF2 lasts, the less of it is needed, so the lower the cost.

A team led by Pavel Dvorak investigated the folded FGF2 origami and identified parts that looked particularly unstable. They then exchanged some of the letters in the protein “name” that correspond to the fragile parts in an effort to create a less wobbly 3D structure. Essentially, they put a bit of “glue” into the structure to make the origami more robust.

The result was the birth of FGF2-3, an enhanced version of FGF2 with the power of increased stability and longevity. It has a greatly increased lifetime of more than seven days and stimulates cell growth much longer than its predecessor. Instead of adding fresh growth mixture for the cultivated meat cells every day, you can now do it just once a week. Therefore, the discovery of FGF2-3 has brought us closer to the goal of making cultivated meat a cost-competitive food on the supermarket shelves.

Of course, the FGF2 success story represents only one step, and the technology behind cultivated meat still has a long way to go. Much more protein origami will be needed to help us end industrial animal farming for good. A shift towards a safe, sustainable and equitable food system can be our generation’s legacy, but an immense collaboration is required: scientists, consumers, farmers, and policymakers must show a collective commitment to forge change, for good and forever.