What is Proteomics • is the large-scale study of proteins, particularly their structures and functions • the qualitative and quantitative comparison of proteomes under different conditions to further unravel biological processes.
Genomics & Proteomics • After genomics, proteomics is often considered the next step in the study of biological systems. It is much more complicated than genomics mostly because while an organism's genome is more or less constant, the proteome differs from cell to cell and from time to time. • This is because distinct genes are expressed in distinct cell types. This means that even the basic set of proteins which are produced in a cell needs to be determined
Why • The Genome Has been Mapped • But Proteome is yet not Mapped
Terminologies • Ion Trap :is a combination of electric or magnetic fields that captures ions in a region • Tandem mass spectrometry, also known as MS/MS, involves multiple steps of mass spectrometry selection, with some form of fragmentation occurring in between the stage
Bottom-up proteomics is a common method to identify proteins and characterize their amino acid sequences and post-translational modifications by proteolytic(protease enzyme)digestion of proteins prior to analysis by mass spectrometry
Top-down proteomics is a method of protein identification that uses an ion trapping mass spectrometer to store an isolated protein ion for mass measurement and tandem mass spectrometry analysis
Advantages of top down strategies • The potential access to the complete protien sequence. • The ability to locate and characterize PTMs. • The time-consuming protien digestion required for bottom-up methods is eliminated.
Disadvantages of top down. • Too expensive to purchase. • Doesn't work well with intact proteins larger than about 50 KDs • Takes time.