ISOLATION AND CHARACTERIZATION OF PROTEINS FROM HUMAN LYMPHOCYTE NUCLEI USING MATRIX-ASSISTED LASER DESORPTION IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRY AND POST-SOURCE DECAY ANALYSIS/

The cell nucleus plays an essential role in all aspects of cell functi on, including DNA replication, gene transcription, RNA processing and cell division, Within the cell nucleus there are many proteins and pep tides that have regulatory roles, Although several higher molecular we ight protein components (>30 kDa) have been identified and characteriz ed, limited information is available for the lower molecular weight co mponents, Nuclei from human peripheral blood lymphocytes were isolated and rapidly characterized by employing a strategy using reversed-phas e high-performance liquid chromatograph, tryptic digestion, and post-s ource decay analysis of matrix-assisted laser desorption/ionization (M ALDI) ions in combination with database searches. Database searches ut ilizing molecular weight, proteolytic digest fragments, and peptide se quence results identified known proteins. The results illustrate the u sefulness of MALDI as a tool in the characterization of low abundance proteins in the cell nucleus. (C) 1997 by John Wiley & Sons, Ltd.