From Lab Benches to Life-Saving Therapies, the Tiny Powerhouses Inside Cells Are Revolutionizing Science
In the intricate world of the cell, enzymes are the tireless molecular machines making life possible. These specialized proteins catalyze nearly every chemical reaction in our bodies, from digesting food to repairing DNA. Imagine a factory where thousands of highly specialized workers are simultaneously building, repairing, and recycling—this is the bustling environment inside every single cell. Now, scientists are learning to harness these natural powerhouses by using enzyme-containing cells and their extracts, creating powerful tools that are revolutionizing fields from medicine to sustainable technology. This isn't just about understanding life's blueprint; it's about learning to reprogram its very machinery to fight disease, create new materials, and build a healthier future.
Enzymes are biological catalysts, meaning they dramatically speed up specific chemical reactions without being consumed in the process. Technically speaking, an enzyme is almost always a protein that speeds up the rate of a specific chemical reaction in the cell. The enzyme is not destroyed or altered during the reaction and is used repeatedly 7 . A single cell contains thousands of different types of enzyme molecules, each specific to a particular chemical reaction 7 .
Projected growth of industrial enzymes market 9
Without enzymes, the chemical reactions essential for life would occur too slowly to sustain us. The enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCo), which incorporates CO₂ into plants during photosynthesis, is so fundamental to life on Earth that it makes up about 30% of the total protein in a plant leaf, making it the most abundant protein on our planet 7 .
Instead of painstakingly synthesizing compounds through traditional chemistry, researchers increasingly use entire cells or cell extracts as production platforms. These cellular systems come in two primary forms:
Genetically engineered microorganisms like bacteria or yeast are programmed to produce and utilize specific enzymes for industrial production. For example, ruminants like cows use cellulase enzymes produced by microbes in their stomachs to break down plant cellulose into absorbable nutrients—since the cow itself produces no cellulose-digesting enzymes 7 .
Extracts containing a cell's enzymatic machinery without the intact cell itself. These extracts contain all the natural enzymes, cofactors, and biological components needed to perform complex reactions without maintaining living cells.
The global market for industrial enzymes is expected to grow up to $9.2 billion by 2027, reflecting their expanding applications 9 .
A groundbreaking discovery from an international research team in July 2025 perfectly illustrates how continued exploration of cellular enzymes reveals profound new biological mechanisms. Researchers identified a new protein, PEX39, that acts like a relay racer, specifically transporting enzymes into cellular compartments called peroxisomes 1 .
Peroxisomes are tiny vesicles filled with enzymes that are present in all cells, with particularly high concentration in liver cells. They are involved in various important metabolic reactions, including the breakdown of fatty acids and the formation of biomembranes such as the myelin sheath of nerve fibers. They also help to detoxify cells by breaking down harmful hydrogen peroxide 1 .
When peroxisomes malfunction, the consequences can be severe. Rare hereditary disorders of the Zellweger spectrum, where peroxisomes are missing or impaired, can lead to liver, kidney, and brain dysfunction, with severe forms often proving fatal within months 1 .
Special proteins called peroxins (PEX) are responsible for importing enzymes into peroxisomes. "We have identified a new peroxin, PEX39, which is involved in enzyme import through a previously unknown mechanism," says Daniel Wendscheck, first author of the publication 1 . This discovery is extraordinary because not a single new human peroxin has been described in the last 20 years 1 .
The way PEX39 works can be compared to a relay racer: It grabs the enzymes to be transported, carries them like a baton to the peroxisomes, and passes them on to the next racer of the import chain at the peroxisomal membrane 1 .
"Although peroxisomes were discovered 70 years ago, they still hold many mysteries. Our goal is to solve these mysteries using the latest methods of high-resolution mass spectrometry and structural analysis."
The research journey began with mass spectrometric analyses of protein complexes from yeast, which provided the first clue that PEX39 might play a role in peroxisomes 1 . The confirmation came from engineering a yeast mutant lacking PEX39, which grew very poorly on oleic acid—a carbon source that yeast metabolizes exclusively in peroxisomes 1 . This elegant approach demonstrated the protein's critical function, later confirmed in human cells.
Discovering new enzymes like PEX39 requires sophisticated tools to find microscopic needles in nature's vast haystack. One cutting-edge approach is the Genetic Enzyme Screening System (GESS), a high-throughput method that can screen massive genetic libraries for novel enzyme activities .
The GESS method uses engineered Escherichia coli bacteria containing a special genetic circuit that triggers a fluorescent signal when the bacteria encounter specific small molecules, particularly phenolic compounds like phenol or p-nitrophenol . Since many enzymatic reactions produce these phenolic compounds from various substrates, this single system can theoretically screen for over 200 different types of enzymes simply by providing different substrates .
Creating a metagenomic library—a collection of genetic material isolated directly from environmental samples—in E. coli cells using a fosmid vector .
Introducing the GESS genetic circuit, which contains the fluorescence reporter system, into the metagenomic library .
Using Fluorescence-Activated Cell Sorting (FACS) to remove naturally fluorescent cells that would otherwise contaminate results, ensuring only relevant enzymes trigger the signal .
Incubating the sorted library cells with specific substrates (like p-nitrophenyl acetate for lipases or p-nitrophenyl-β-D-cellobioside for cellulases), then using FACS again to isolate the fluorescent cells that have produced the phenolic compounds through enzyme activity .
Sequencing the genetic material of the fluorescent cells to identify the novel enzyme genes .
This powerful approach has successfully identified previously unknown enzymes, including the first thermolabile alkaline phosphatase found in cold-adapted marine metagenomes . The ability to rapidly screen millions of genetic samples from diverse environments dramatically accelerates the discovery of enzymes with novel properties, opening new possibilities for industrial applications and scientific understanding.
The practical applications of enzyme-containing cells and extracts span multiple fields, creating more sustainable processes and powerful new technologies.
Enzymes are revolutionizing medicine through applications in therapy, diagnosis, and drug development:
A novel approach called Targeted Protein Degradation (TPD) harnesses the cell's own quality-control machinery to eliminate disease-causing proteins entirely rather than simply blocking their activity 4 . At the heart of most TPD strategies are E3 ligases, enzymes that tag unwanted proteins with ubiquitin molecules, marking them for destruction 4 .
Researchers at the University of Geneva discovered that the CH25H enzyme in cancerous lymphatic cells plays a crucial role in activating immune cells 8 . This enzyme converts cholesterol into 25-hydroxycholesterol, which appears to disrupt the tumor's defence mechanisms and allow for better activation of anti-tumour immunity 8 .
Enzymes used as drugs have two important characteristics that are different from traditional drugs: they bind and act on their targets with great affinity, and they are highly specific catalysts that convert multiple target molecules to desired products 7 . These features make enzymes specific and potent drugs that can accomplish therapeutic biochemistry in the body that small molecules can't 7 .
"The specificity of enzyme has been harnessed for the extraction of valuable compounds from several natural resources," falling under the category of green extraction technologies because it's environmentally friendly 5 . Enzymes help break down plant cell walls to release bound bioactive compounds, using water as a solvent instead of harsh chemicals 5 9 .
Enzymes can create prebiotic oligosaccharides and release phenolic compounds from plant materials, contributing to the development of functional foods.
Enzyme-treated plant extracts are used in green nanoparticle synthesis, producing materials with antimicrobial properties.
Enzyme-assisted extraction represents a green alternative to traditional chemical methods for obtaining valuable compounds.
| Research Reagent | Function in Enzyme Research |
|---|---|
| Cell Dissociation Reagents (Trypsin, TrypLE) | Break down proteins that anchor cells to surfaces, allowing researchers to collect adherent cells for study while maintaining viability 6 . |
| Balanced Salt Solutions (PBS, DPBS, HBSS) | Provide a physiological environment that maintains the structural and physiological integrity of cells during experiments 6 . |
| Recombinant Proteins | Highly pure, biologically active proteins used as standards in enzyme assays or to study protein-protein interactions 6 . |
| Cell Culture Grade Water | Ultra-pure water free of contaminants, salts, and endotoxins that could interfere with enzymatic reactions or cell culture systems 6 . |
| Enzyme Substrates (e.g., p-nitrophenyl derivatives) | Compounds that are converted by specific enzyme activities into detectable products (like colored or fluorescent molecules), enabling enzyme detection and measurement . |
| Enzyme Inhibitors | Compounds that specifically block enzyme activity, crucial for studying enzyme function and developing therapeutic drugs 2 . |
The field of enzyme-containing cells and extracts continues to evolve at an exciting pace. As Professor Bettina Warscheid, whose team discovered PEX39, notes: "Although peroxisomes were discovered 70 years ago, they still hold many mysteries. Our goal is to solve these mysteries using the latest methods of high-resolution mass spectrometry and structural analysis" 1 .
From the discovery of new cellular transport mechanisms like PEX39 to the development of revolutionary therapies that harness our cellular machinery to fight disease, the exploration of enzyme-containing cells represents one of the most promising frontiers in modern science. As we continue to decipher the intricate workings of these molecular factories, we move closer to harnessing the full potential of nature's own catalytic power to address some of humanity's most pressing challenges in health, sustainability, and technology.