Humans use proteins for a variety of purposes, including food and nutrition, industrial research, and within the healthcare sector. Most proteins occur naturally, either within the human body or other organisms. However, certain research applications may require large amounts of a specific protein, and these large quantities don’t often occur in nature.
The study of proteins and their functions within the human body is an essential field of research, as protein dysfunction can result in serious diseases, disorders, and developmental abnormalities. Continued research has led to crucial discoveries regarding therapeutic drugs and treatments for these disorders. To achieve the quantities of proteins needed for this research, scientists must endeavor to produce them. One of the primary means of producing proteins in this magnitude is through recombinant protein purification.
What Is Recombinant Protein Purification?
Recombinant proteins are proteins resulting from a gene-modified, in such a way that it enhances the protein’s expression. These genes are usually isolated from humans but expressed in a cultured vector, like bacteria, yeast, or animal cells. There are many opinions regarding which vectors are best for producing high-quality samples of various proteins. Recombinant technology results in large quantities of the desired protein without the need for continued isolation from a human subject.
Once large amounts of a protein have been produced, scientists must isolate the desired protein. This process, known as recombinant protein purification, involves a number of general steps including:
- Separating the producer cells from the culture medium
- Separating the desired protein from contaminants
- Further elimination of contaminants as required for therapeutic proteins
Once the purified protein is isolated, it can be used for a number of research applications without experiencing interference from other agents.
Examples of Recombinant Protein Purification
In order to adequately purify recombinant proteins for use in food and nutrition, scientists have devised a number of methodologies. Each approaches the task of purification a bit differently and may provide alternating levels of purity for one or more of these purposes. Currently, the methods most commonly utilized for protein purification include:
- Affinity chromatography. This method involves adding a structure known as a tag onto the desired protein. Then, the tagged proteins are separated based on their interaction with a particular matrix. This method is the most specific due to its selective isolation of the tagged protein.
- Gel filtration chromatography. With gel filtration, scientists use a resin with pores of a specific size. Proteins and contaminants are filtered through the resin and separated based on the difficulty with which they pass.
- Ion exchange chromatography. In this method, scientists expose a sample to differing amounts of pH and temperature. Targeted proteins are isolated due to the specific electric charge they display under these conditions.
- Polarity-based chromatography. This category actually consists of two methods, known as reverse phase chromatography and hydrophobic interaction chromatography. Polarity-based chromatography separates target proteins from contaminants by observing measures of their polarity.
As recombinant protein production and purification continue to provide large samples of proteins for study, researchers will be able to further understand how protein structure, function, and dysfunction affect the human body. Advances in the development of protein and peptide drugs as a therapeutic treatment for diseases caused by protein malfunction like Alzheimer’s, Parkinson’s, and cystic fibrosis could help millions achieve normal lives. The future of recombinant protein purification remains a crucial step in this process.