Proteome Stabilization

Determination of a protein's identity based on its peptide mass fingerprint and/or ion fragmentation sequencing is an important aspect of proteome mining. The ability to chemically tag and measure relative amounts of proteins in cells by mass spectrometry provides additional information on changes in gene expression or metabolism that are both relevant and responsive to the environment. There is a critical need however for sample preparation protocols that reduce procurement-related changes to cellular proteomes during separation science and analysis. Before any significant proteomics-based sample workflow is initiated, Larial recommends evaluating protein stabilities to ensure the reliability of protein identification and expression datasets. Most micro-organismal and cellular proteomes are inherently unstable. Significant information loss and sample analysis inconsistencies arise when appropriate measures are not taken to protect proteins from chemical modifications occurring as a result of proteolysis, reactive side chain modifications, redox reactions, chemical conjugation etc. The use of reduced temperatures or inclusion of protease inhibitor cocktails often fail to provide adequate protection for complex protein mixtures Lengthy separation science procedures needed to enrich low abundance targets further compromise the integrity of the resulting fractions. Finding remedies to proteome instability problems often requires the development of proprietary reagents and procedures that promote the acquisition of reliable datasets. To this end, Larial has focused on developing effective proteome stabilization technologies. Of particular note is FixElix™ , an effective proteolytic enzyme inhibitor reagent developed by Larial scientists for stabilization of industrial yeast proteomes. Use of an effective proteome stabilization reagent prior to sample preparation and analysis is essential to preserve dataset fidelity and reduce quantitative errors.