Mass spectrometric methods for the analysis of protein structures are being improved, applied and tested in independent and collaborative research projects in proteomics. Projects in separation methods and data processing are in progress. In the past year, progress has been made on implementation of a computational environment for mass spectrometric proteomic data processing;isotope labeled fusion proteins as protein standards;quantification of identified and unidentified components in sets of complex liquid chromatography-high resolution mass spectrometry data; and multi-institutional collaborative studies on standards in proteomics. The processing and mining of mass spectrometric proteomic data requires a system allowing investigators desktop computer access to terabytes of data;the ability to repeatedly probe their data with emerging software tools;and the ability to transfer this data to public archival repositories. A versatile system has been implemented in LNT and will be shared with other proteomics groups in NIH.