Protein Proteomics – Abstract

Proteomics is an important field of study, because the analysis of protein interactions and protein structure is critical to understanding protein function.  Modifications in the protein, especially post-translational modifications, are key to understanding function and roles of the proteins, which is why there is a need in biochemistry to sequence proteins.  In this research experiment, E. Coli bacterial cells are being lytically infected with the t7 phage.The lytic cycle starts when the bacteriophage infects the cell, and the phage DNA then replicates and creates phage protein in the E. Coli cell.2   My Honors project will be conducted in close collaboration with Professor Williamson’s lab.  E. coli bacterial cells will be infected with the t7 phage at various times (5, 25, 45 and 65 minutes), and we will be looking for the differences in the proteins expressed based on the different time exposure of the t7 phage.  By looking for modifications in the proteins on the different time exposure, protein structure and function can then be deduced.  The procedure includes growing the cell cultures, extracting and separating the proteins, and then analyzing the peptide fragments using HPLC-ESI-MS/MS and the protein database SEQUEST.  The importance of this project is that we are using a proteomics procedure that uses a HPLC-ESI-MS/MS (high pressure liquid chromatography-electrospray ionization-tandem mass spectrometer) method.  Mass spectrometry has emerged as a core tool for protein analysis and sequencing, especially since most mass spectrometers have advanced in resolution, mass accuracy and sensitivity.3,4  As a time and money efficient tool, mass spectrometry is important in the field of proteomics, and with this Honors project we are trying practice bioanalysis using a HPLC-ESI-MS/MS method.

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