Exploration of peptides that are increased in the plasma of diabetic mice and are the substrate of dipeptidyl peptidase III

Diabetes mellitus (DM) causes the change in the components of the plasma, which may induce tissue and organ injuries, including the heart and kidney. In the diabetic model db/db mice, intravenous injection of purified dipeptidyl peptidase III (DPPIII) attenuated the heart and kidney damages provoked by DM without alteration in blood glucose level. This led us to hypothesize that there might be peptide(s) that are involved in the progression of the DM-mediated damages and are cleaved by DPPIII. To explore the peptides, the whole peptidomics analysis was conducted using tandem mass spectrometry, in which peptides derived from the plasma of PBS-infused C57BL/6 mice, PBS-infused db/db mice, and DPPIII-treated db/db mice were compared. All of the lists of the peptides in the three mouse groups were shown in the raw data formatted and excel files.