Proteins are distinct from one another with respect to their number, type, and sequence of amino acids making up the polypeptide backbone. Therefore, they have unique nutritional attributes, physicochemical properties, and molecular structures.
There are companies and CDMOs that have protein analysis as their main line of work. Currently, there are three major techniques for protein analysis, i.e. western blotting, protein separation, and protein identification. In this article, we’re taking a brief look at each of them.
1. Western Blotting
Western blotting involves three steps for the identification of specific proteins from a complex mixture. They are separated by size, transferred to provide solid support, and the target protein is marked for visualization. Experts use a proper primary and secondary antibody for marking the target protein.
Immunoblotting is the most commonly used variation of the western blot technique. It’s used for the detection of certain proteins within a given tissue homogenate sample. In the initial stage, the sample of proteins gets electrophoresed. This separates them on the basis of their molecular weight. The next step is to transfer them to a membrane for probing using specific antibodies for the protein under observation.
Such procedures require highly technical equipment, experts, and resources. Hence, they’re only accessible to a protein analysis, development and research company with both experience and cutting-edge technology.
2. Protein Separation
Protein separation or “protein electrophoresis” involves the separation or purification of proteins by using a gel matrix. Experts observe the mobility of proteins in an electrical field. It’s a critical approach of protein analysis for studying the function and effect of a specific protein when it is introduced into an organism.
3. Protein Identification
The two common methods in which protein identification is generally carried out are Edman Degradation and Mass Spectrometry.
Edman Degradation
Edman degradation is a popular method of identifying proteins that was first developed by Pehr Edman. In it, amino acids are sequenced in a peptide. Then, the amino-terminal residue gets labeled and cleaved without disturbing the peptide bonds between other residues of amino acids.
Protein Mass Spectrometry
Mass spectrometry is a technique used for protein analysis. It determines the masses of particles by measuring the mass-to-charge ratio of charged particles. It also studies the elemental composition of a molecular sample. It’s also used for elucidating the molecules’ (such as peptides) chemical structure.
It’s a key method for determining the accurate mass of proteins, as well as for their proper characterization. Experts have developed various methods and a number of instrumentations for the many uses of this technique.
The application of protein mass spectrometry as a mainstream method of protein analysis saw a surge in popularity in the 1980s, right after the development of ESI and MALDI.
Conclusion
Protein analysis holds massive importance in the world of biosciences. Proteins differ from each other in terms of their size, physicochemical properties, and molecular structure. These differences allow protein analysts to characterize them by identification or separation techniques. In this article, we’ve shared the three traditional methods used by modern-day science.
