Production and characterization of the recombinant Islet Neogenesis Associated Protein (rINGAP)

Islet Neogenesis Associated Protein (INGAP) is implicated in pancreatic islet neogenesis. INGAP peptide, a pentadecapeptide comprising amino acids 104–118, reverses diabetes in rodents and improves glucose homeostasis in patients with diabetes. The mechanism of INGAP action is unknown, but such studies would benefit from the availability of the full-length recombinant protein (rINGAP).Here we report the production of rINGAP from 293-SF cells following lentiviral transduction, and its characterization by MALDI-TOF and Q-TOF Mass Spectrometry, and HPLC.Importantly, we show that rINGAP exhibits 100× the bioactivity of INGAP peptide on a molar basis in an in vitro assay of human islet regeneration.