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Unlock This CourseImagine if we could turn bacteria into tiny factories that produce life-saving medicines. That's exactly what genetic technology allows us to do! By inserting human genes into bacteria, scientists can make these microorganisms produce human proteins that can treat diseases like diabetes and growth disorders.
This process has revolutionised medicine, making treatments cheaper, safer and more widely available than ever before. Before genetic engineering, many of these proteins had to be extracted from human or animal sources, which was expensive, risky and often in short supply.
Key Definitions:
Bacteria are perfect for protein production because they reproduce quickly, are easy to grow in large quantities and can be modified to produce almost any protein we need. E. coli bacteria can double their population every 20 minutes under ideal conditions!
Creating bacteria that produce human proteins involves several precise steps. Think of it like creating a recipe that bacteria can follow to make exactly what we want.
The process begins with identifying and isolating the human gene that codes for the desired protein. This gene must then be inserted into bacterial DNA so the bacteria can read the instructions and produce the protein.
Scientists identify and extract the specific human gene needed. This gene contains the instructions for making the desired protein.
A bacterial plasmid is cut open using restriction enzymes at specific recognition sites, creating 'sticky ends' where new DNA can be inserted.
The human gene is inserted into the plasmid using ligase enzyme, which seals the DNA fragments together to create recombinant DNA.
The modified plasmid is introduced into bacterial cells through a process called transformation, often using heat shock or electrical pulses.
Bacteria that successfully took up the plasmid are identified using antibiotic resistance markers or other selection methods.
The modified bacteria are grown in large fermenters where they multiply and produce the human protein, which is then harvested and purified.
Before 1982, diabetics relied on insulin extracted from pig and cow pancreases. This animal insulin sometimes caused allergic reactions and was expensive to produce. The first genetically engineered human insulin, called Humulin, was produced by inserting the human insulin gene into E. coli bacteria. Today, virtually all insulin used by diabetics worldwide is produced this way, making it safer, more consistent and widely available.
Genetic engineering has enabled the production of numerous life-saving proteins that would otherwise be impossible or extremely difficult to obtain in sufficient quantities.
The success of insulin production opened the door for many other therapeutic proteins. Each has transformed treatment for millions of patients worldwide.
Used to treat children with growth hormone deficiency. Previously extracted from human pituitary glands from cadavers, which carried the risk of transmitting diseases like Creutzfeldt-Jakob disease.
Factor VIII and Factor IX are produced for haemophiliacs. Before genetic engineering, these proteins were extracted from donated blood plasma, carrying risks of HIV and hepatitis transmission.
These proteins help the immune system fight viral infections and some cancers. They're naturally produced in tiny amounts, making bacterial production essential for therapeutic use.
While bacterial protein production has revolutionised medicine, it comes with both significant benefits and important limitations that scientists continue to address.
The advantages of using bacteria to produce human proteins extend far beyond just making medicine cheaper.
Bacteria grow rapidly and cheaply, making large-scale production economical and accessible worldwide.
No risk of transmitting human or animal diseases, unlike proteins extracted from biological sources.
Genetically identical bacteria produce identical proteins, ensuring consistent therapeutic effects.
Despite the success, bacterial systems have limitations that researchers are working to overcome.
Some human proteins are too complex for bacteria to fold correctly, requiring additional processing steps or alternative production systems like yeast or mammalian cells.
Bacteria cannot add the sugar groups and other modifications that some human proteins need to function properly in the human body.
Scientists are developing new bacterial strains and production methods to overcome current limitations. Some bacteria are being engineered to add human-like modifications to proteins, while others are designed to produce multiple proteins simultaneously. Gene editing technologies like CRISPR are making it easier and faster to create new bacterial production systems.
The ability to produce human proteins in bacteria has fundamentally changed modern medicine, making treatments available to millions who previously had no options.
Bacterial production has democratised access to life-saving medicines. Countries that could never afford to extract proteins from human or animal sources can now produce them locally using bacterial systems.
Developing countries can now produce essential medicines like insulin locally, reducing dependence on expensive imports and improving healthcare access for their populations.
This technology continues to evolve, with scientists working on producing more complex proteins and developing faster, more efficient production methods. The principles you've learned here form the foundation for understanding how genetic engineering is reshaping medicine and biotechnology.