Protein Characterisation by Fourier Transform Mass Spectrometry

Big machines is the name of the game. Check that beauty out! Fourier Transform Mass Spectrometry (FTMS) really is the Rolls Royce of MS, with ultra-high resolution, high sensitivity and multiple MS stages. However, the challenge is not only to operate these machines, my project involves physics, biology, chemistry, engineering, as well as software development. This makes it all the more interesting, since you never lose sight of the whole picture. Proteomics is currently the big buzzword and I think it really is hard to underestimate the importance of proteins. The problem with proteins is that they normally exist at very low concentrations and that their structures are fairly complex. Another complication is the fact that many amino acids in proteins are in fact modified chemically and hence the DNA sequence does not tell you the whole picture. These modifications are very important, since they can de/activate proteins. Mass spectrometry is certainly one of the most sensitive techniques available, but it is also capable of detecting these modifications, since the mass of the molecule will change. The way to figure out where the modification took place, one breaks up the molecule into multiple fragments and from the complementary fragments you can solve the jigsaw puzzle. We will be using mainly two ways to fragment the protein ions, either by adding an electron (electron capture dissociation) or irradiating the ions with a laser (infra-red muli-photon dissociation). The ultimate aim of this work is to make the identification of post-translational mofications routine.