For selective C-terminal derivatization of peptides and proteins, we have devised a method for activating the C-terminal carboxyl group by extending the oxazolone chemistry. A mixture of formic acid and acetic anhydride was found to be effective for the formation of an oxazolone, which was converted to an active ester in situ in the presence of a phenol or an N-hydroxide. In particular, the resulting active ester with pentafluorophenol facilitated the subsequent reaction with an amine and the hydrazine derivative to yield the C-terminal amide and hydrazide, respectively. The peptides thus coupled with arginine methyl ester or 2-hydrazino-2-imidazoline containing the guanidino moiety exhibited the positive-ion peaks in matrix-assisted laser desorption/ionization (MALDI) mass spectra with appreciably enhanced intensities. As expected from the reaction mechanism, the carboxyl groups of aspartic and glutamic acid residues were not modified, while the amino groups that could react with the activated peptides were concomitantly protected by formylation. The MALDI peaks corresponding to the C-terminal peptide fragments of proteins were specifically enhanced, discriminating against those from internal peptides that were not tagged with a positive charge. In favorable cases, the C-terminal peptide fragments were clearly discerned by MALDI-MS after chymotryptic digestion and were identified by their MALDI postsource decay analysis. Based on these results, we suggest a method for C-terminal sequencing of a protein.
Canada's federal funding agencies are following the directions of funding agencies in the United States and United Kingdom, and will soon require a data management plan in grant applications. The University of Manitoba Libraries in Canada has started planning and implementing research data services, and education is seen as a key component. In June 2014, the New England Collaborative Data Management Curriculum (NECDMC) (Lamar Soutter Library, University of Massachusetts Medical School 2014) was piloted and used to provide data management training for a group of subject librarians at the University of Manitoba Libraries, in combination with information about data-related policies of the Canadian funding agencies and the University of Manitoba. The seven NECDMC modules were delivered in a seminar style, with emphasis on group discussions and Canadian content. The benefits of NECDMC-adaptability and flexible framework-should be weighed against the challenges experienced in the pilot, mainly the significant amount of time needed to create local content and complement the existing curriculum. Overall, the pilot showed that NECDMC is a good, thorough introduction to data management, and that it is possible to adapt NECDMC to the local and Canadian settings in an effective way.
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