The key difference between targeted and untargeted proteomics is that the targeted proteomics aims at measuring the abundance of a specific protein while untargeted proteomics does not target a specific protein.
Proteomics is the large-scale study of proteins, their structures, and functions. It studies the entire protein complement in a cell, tissue or an organism under specific conditions. There are two types of proteomics as targeted proteomics and untargeted proteomics.
CONTENT
1. Overview and Key Difference
2. What is Targeted Proteomics
3. What is Untargeted Proteomics
4. Similarities Between Targeted and Untargeted Proteomics
5. Side by Side Comparison – Targeted vs Untargeted Proteomics in Tabular Form
6. Summary
What is Targeted Proteomics?
As its name indicates, targeted proteomics targets a specific protein or a peptide in a complex mixture of proteins for analysis. Then it analyzes the presence and quantity of that preselected specific protein. This method is possible for only one sample or across multiple samples. This method is suitable even for a specific group of proteins. It results in more precise, quantitative and sensitive data. Moreover, mass spectrometry coupled with targeted proteomics produces more accurate reliable measurements. This method uses triple quadrupole mass spectrometer (QQQ) for its analysis.
Figure 01: Proteomics
Targeted proteomics is a suitable method if you want to verify if a knockdown target is actually knocked down or when you want to quantify a particular protein/peptide in blood serum, cerebral fluid or in cell lysate etc. You can also use it if you want to check whether a particular protein is differentially expressed across samples or during a time course experiment.
What is Untargeted Proteomics?
Untargeted proteomics, as the name mentions, does not target a specific protein or peptide for its analysis. Discovery proteomics is another name for Untargeted proteomics. In fact, it is a more ‘global’ analysis. Generally, performing untargeted proteomics is to answer the question “what protein or proteins are in this sample or multiple samples?”. This method is not sensitive as targeted proteomics. But it can identify and measure many proteins including novel proteins. Untargeted proteomics can produce both quantitative and qualitative measurements.
What are the Similarities Between Targeted and Untargeted Proteomics?
- Both targeted and untargeted proteomics measure proteins in samples.
- They are important in proteome analysis.
- These methods use mass spectrometry.
What is the Difference Between Targeted and Untargeted Proteomics?
Firstly, targeted proteomics is the determination of the presence and quantity of a particular protein or peptide in complex mixture of proteins. In contrast, untargeted proteomics is the quantitative and qualitative study of proteins present in a sample or samples without targeting a particular protein. Targeted proteomics is performed with preselected or targeted proteins while untargeted proteomics is performed to find out the types of proteins in this sample. Moreover, targeted proteomics is more sensitive than untargeted proteomics.
Summary – Targeted vs Untargeted Proteomics
To sum up, targeted and untargeted proteomics are two types of protein studies. As their names suggest, targeted proteomics targets a specific protein while untargeted proteomics does not target a specific protein. This is the difference between targeted and untargeted proteomics.
Reference:
1. “Targeted Proteomics.” UC Davis Proteomics Core, Available here.
2. “Proteomics/Introduction to Proteomics.” Music Theory/Modes – Wikibooks, Open Books for an Open World, Available here.
Image Courtesy:
1.”Proteomics” By Xxl7441 at English Wikibooks – Transferred from en.wikibooks to Commons (Public Domain) via Commons Wikimedia