일 시 : 2011년 4월 7일, 오후 5:00
장 소 : 500동 목암홀

-Abstract-
  In this presentation, we present a novel chemical tagging method for the effective enrichment of proteins (peptides) with specific modification. Protein tyrosine nitration (PTN) is a post-translational modification that is related to several acute or chronic diseases. Although nitrated proteins as markers of oxidative stress are confirmed by immunological assays in various affected cells or tissues, it is not known how many different types of proteins in living cells are nitrated. Since PTN is a low-abundance post-translational modification, development of an effective enrichment method for nitrated proteins is needed to detect nitrated peptides or proteins from the limited amount of pathophysiological samples. Recently, we developed an enrichment method using specific chemical tagging. Nitroproteome profiling using a novel chemical tagging and mass spectrometry was validated by model proteins. Furthermore, we successfully identified numerous nitrated proteins from the various biological systems including embryonic stem cell and Huh7 human hepatoma cell line.
  Recent developments in imaging mass spectrometry (IMS) have allowed complete mapping of the biological molecules including phospholipids (PLs) that are the major building block molecules of cellular membranes. The IMS technique can detect different classes of PLs as well as their location information directly from tissue sections. PL head groups carry either positive and/or negative charges; therefore, IMS experiments must be conducted in both positive- and negative-ion mode to detect all types of phospholipids. Recently, we developed an optimized matrix preparation for IMS experiments in both ion modes that maximize PL identification from a single brain tissue section. The optimized matrix showed improved stability and consistency during both ion mode experiments and successfully identified >100 peaks of PLs determined by parent ion m/z value. Further tandem mass spectrometric analysis (MS/MS) was performed to those PLs that are anatomically important according to their distribution on rat brain tissue section.