title: Enhanced Peptide Stability Against Protease Digestion Induced by Intrinsic Factor Binding of a Vitamin B12 Conjugate of Exendin-4.
abstract: Peptide digestion from proteases is a significant limitation in peptide therapeutic development. It has been hypothesized that the dietary pathway of vitamin B12 (B12) may be exploited in this area, but an open question is whether B12-peptide conjugates bound to the B12 gastric uptake protein intrinsic factor (IF) can provide any stability against proteases. Herein, we describe a new conjugate of B12 with the incretin peptide exendin 4 that demonstrates picomolar agonism of the glugacon-like peptide-1 receptor (GLP1-R). Stability studies reveal that Ex-4 is digested by pancreatic proteases trypsin and chymotrypsin and by the kidney endopeptidase meprin β. Prebinding the B12 conjugate to IF, however, resulted in up to a 4-fold greater activity of the B12-Ex-4 conjugate relative to Ex-4, when the IF-B12-Ex-4 complex was exposed to 22 μg/mL of trypsin, 2.3-fold greater activity when exposed to 1.25 μg/mL of chymotrypsin, and there was no decrease in function at up to 5 μg/mL of meprin β.
authors.affiliation: Department of Chemistry, Center for Science and Technology, Syracuse University , 111 College Place, Syracuse, New York 13244, United States.
authors.forename: Ron L
authors.initials: RL
authors.lastname: Bonaccorso
authors.affiliation: Department of Medicine, State University of New York, Upstate Medical University , Syracuse, New York 13210, United States.
authors.forename: Oleg G
authors.initials: OG
authors.lastname: Chepurny
authors.affiliation: Institute of Biochemistry, Christian-Albrechts-University , 24118 Kiel, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Becker-Pauly
authors.affiliation: Department of Medicine, State University of New York, Upstate Medical University , Syracuse, New York 13210, United States.|Department of Pharmacology, State University of New York, Upstate Medical University , Syracuse, New York 13210, United States.
authors.forename: George G
authors.initials: GG
authors.lastname: Holz
authors.affiliation: Department of Chemistry, Center for Science and Technology, Syracuse University , 111 College Place, Syracuse, New York 13244, United States.|Department of Medicine, State University of New York, Upstate Medical University , Syracuse, New York 13210, United States.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Doyle
mesh_terms: D002918:Chymotrypsin / Q000494:pharmacology*; D000077270:Exenatide; D057809:HEK293 Cells; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007437:Intrinsic Factor / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin / Q000494:pharmacology*; D014688:Venoms / Q000494:pharmacology*; D014805:Vitamin B 12 / Q000737:chemistry* / Q000378:metabolism; D000097789:Glucagon-Like Peptide-1 Receptor Agonists; D000067757:Glucagon-Like Peptide-1 Receptor
chemical_list: D002918:Chymotrypsin; D000077270:Exenatide; D007004:Hypoglycemic Agents; D007437:Intrinsic Factor; D008666:Metalloendopeptidases; D010455:Peptides; D014357:Trypsin; D014688:Venoms; D014805:Vitamin B 12; D000097789:Glucagon-Like Peptide-1 Receptor Agonists; C000593833:GLP1R protein, human; D000067757:Glucagon-Like Peptide-1 Receptor; C095663:meprin B
keywords: AKAR3; exendin-4; intrinsic factor; trypsin; vitamin B12