At DC Biosciences, we offer a broad range of mass spectrometry-based protein identification methods.
Proteins are large, intricate molecules that generate complex patterns when analysed by mass spectrometry (MS). Therefore, to identify your proteins, it is often much easier to digest protein mixtures into smaller components called peptides. These peptides can then be fragmented in a mass spectrometer to generate MS2 spectra. This commonly-used approach is known as “bottom-up” proteomics.
It is quite challenging and time-consuming to routinely evaluate and annotate MS2 spectra and determine the identity of each and every individual peptide. Thus, the MS2 spectra are searched against a protein database and the information compared. High-quality matches between MS2 spectra and peptides in the database confirms identity. De novo sequencing can still be necessary when the protein sequence is unknown, or amino acid substitutions are suspected.
For samples of low complexity, e.g., assessing the purity of an isolated or recombinant protein, intact protein mass determination can provide valuable information.