The Protein Man's Blog

Protein Fractionation in Protein Research: What Does It Do?

Written by The Protein Man | Mar 20, 2013 10:00:00 AM

Question:

What is the role of protein fractionation in protein research?  

The Protein Man Says:

Protein fractionation plays an important role in proteomic research since it simplifies the protein pool for easier analysis to allow for more accurate interpretation. If you have been doing such research for quite some time now, you probably know that the analysis of a particular proteome is usually inhibited by the vast amounts of proteins present in the sample. By analyzing too many proteins with varying properties all at once, you will get a significantly decreased resolution and this may greatly affect the results of your research.

How Does Protein Fractionation Work?

So, how does protein fractionation make things easier for you? Well, it works by reducing the size of the protein pool and removing highly expressed genes to bring low abundant proteins into a more dynamic range. However, due to the wide variation in protein properties, there is no single technique that is known to work in all situations. Instead, different fractionation formats should be used to get the results that you need.

The different fractionation formats that can aid you in your research includes the following:

  • Sequential or differential fractionation. This technique is most commonly used in identifying unknown proteins in a sample. It separates proteins based on the differences in their solubility while ignoring cellular architecture and protein translocation. As such, this should only be used when your ultimate goal is to quickly simplify the protein pool in your sample. 

  • Subcellular fractionation. This technique separates the individual components of cellular units through differential centrifugation. In addition, it also facilitates easier protein identification by significantly reducing the complexity of the protein sample.

  • Abundant protein removal. This simplifies the proteomes by removing highly abundant proteins such as albumin and immunoglobulin.

  • Chromatographic techniques. Protein fractionation can also be done by pooling proteomes based on particular characteristics such as molecular weight, protein charge, hydrophobicity and antigen-ligand interaction.

In most cases, a combination of these techniques is needed to successfully fractionate your protein pool so it pays to know your proteins well.