A class of secreted mammalian peptides with potential to expand cell-cell communication - Capped peptide detection

Using a hybrid computational-biochemical approach, we have demonstrated the endogenous presence of a large and sequence diverse class of orphan, blood-borne peptides that we call “capped peptides.” Capped peptides are post-translationally modified fragments of classically secreted proteins. They exhibit structural and regulatory characteristics similar to other signaling peptides, including N-terminal pyroglutamylation, C-terminal amidation, and cell type-specific expression. Circulating levels of capped peptides are dynamically regulated by internal physiologic states and external environmental stimuli. The data deposited here are the raw .d files from the initial detection of the capped peptides in mouse and human plasma, along with synthetic standards. We are also including the files from evaluating the peptides level under different physiologic conditions: fasting, high fat diet, LPS injection, aging, and exercise.