Biological Mass Spectrometry
Femtosecond laser-induced ionization/dissociation (fs-LID) is a new ion activation method we have developed for the structural analysis of complex biomolecules. The ultrafast laser offers the unique advantage of delivering energy to a population of precursor ions faster than that energy can be vibrationally redistributed.
As a result, we observe a mixture of statistical and non-statistical bond cleavages; in other words, the femtosecond laser is able to break both the strong and weak bonds in the trapped precursor ions. The mass spectra that we collect using fs-LID have more product ion peaks than the corresponding CID spectra, and provide us with more information for mapping out the structure of the original molecule. This becomes particularly useful when trying to identify and locate post-translational modifications on peptides, or determine the branching patterns in carbohydrate-based samples. Potential applications of this technique include disease diagnosis, monitoring, and drug screening.