Archived polyacrylamide gels as a resource for proteome characterization by mass spectrometry

Mass spectrometry was applied to identify protein spots excised from an arc hived two-dimensional polyacrylamide gel that had been dried and stored for eight years at room temperature. All proteins were successfully identified . Detailed characterization of protein digests by matrix-assisted laser des orption/ionization (MALDI) peptide mapping, nanoelectrospray tandem mass sp ectrometry and MALDI-quadrupole time-of -flight mass spectrometry revealed no evidence of protein degradation or modifications that could hamper ident ification of proteins in a sequence database. The experiment with a model p rotein demonstrated that the pattern of tryptic peptides and the yield of i ndividual peptides were not noticeably changed in the in-gel digest of the archived protein spot compared to the digest of the spot excised from a fre sh gel. Thus, the characterization of "archived proteomes" has the potentia l to advance proteomic research without repeating "wet" biochemistry experi ments, that had been perfected in the laboratory years ago.