title: Synthesis, characterization, and pharmacokinetic studies of PEGylated glucagon-like peptide-1.
abstract: Glucagon-like peptide-1-(7-36) (GLP-1) is a hormone derived from the proglucagon molecule, which is considered a highly desirable antidiabetic agent mainly due to its unique glucose-dependent stimulation of insulin secretion profiles. However, the development of a GLP-1-based pharmaceutical agent has a severe limitation due to its very short half-life in plasma, being primarily degraded by dipeptidyl peptidase IV (DPP-IV) enzyme. To overcome this limitation, in this article we propose a novel and potent DPP-IV-resistant form of a poly(ethylene glycol)-conjugated GLP-1 preparation and its pharmacokinetic evaluation in rats. Two series of mono-PEGylated GLP-1, (i) N-terminally modified PEG(2k)-N(ter)-GLP-1 and (ii) isomers of Lys(26), Lys(34) modified PEG(2k)-Lys-GLP-1, were prepared by using mPEG-aldehyde and mPEG-succinimidyl propionate, respectively. To determine the optimized condition for PEGylation, the reactions were monitored at different pH buffer and time intervals by RP-HPLC and MALDI-TOF-MS. The in vitro insulinotropic effect of PEG(2k)-Lys-GLP-1 showed comparable biological activity with native GLP-1 (P = 0.11) in stimulating insulin secretion in isolated rat pancreatic islet and was significantly more potent than the PEG(2k)-N(ter)-GLP-1 (P < 0.05) that showed a marked reduced potency. Furthermore, PEG(2k)-Lys-GLP-1 was clearly resistant to purified DPP-IV in buffer with 50-fold increased half-life compared to unmodified GLP-1. When PEG(2k)-Lys-GLP-1 was administered intravenously and subcutaneously into rats, PEGylation improved the half-life, which resulted in substantial improvement of the mean plasma residence time as a 16-fold increase for iv and a 3.2-fold increase for sc. These preliminary results suggest a site specifically mono-PEGylated GLP-1 greatly improved the pharmacological profiles; thus, we anticipated that it could serve as potential candidate as an antidiabetic agent for the treatment of non-insulin-dependent diabetes patients.
authors.affiliation: Drug Targeting Laboratory, College of Pharmacy, SungKyunKwan University, 300 Chonchon-dong, Jangan-ku, Suwon City 440-746, Korea. kclee@skku.edu
authors.forename: Sang-Heon
authors.initials: SH
authors.lastname: Lee
authors.forename: Seulki
authors.initials: S
authors.lastname: Lee
authors.forename: Yu Seok
authors.initials: YS
authors.lastname: Youn
authors.forename: Dong Hee
authors.initials: DH
authors.lastname: Na
authors.forename: Su Young
authors.initials: SY
authors.lastname: Chae
authors.forename: Youngro
authors.initials: Y
authors.lastname: Byun
authors.forename: Kang Choon
authors.initials: KC
authors.lastname: Lee
mesh_terms: D000818:Animals; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism; D004355:Drug Stability; D005934:Glucagon / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D052216:Glucagon-Like Peptide 1; D004763:Glucagon-Like Peptides; D006207:Half-Life; D007004:Hypoglycemic Agents / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism; D008297:Male; D010446:Peptide Fragments / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D010599:Pharmacokinetics; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000494:pharmacology; D011498:Protein Precursors / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013329:Structure-Activity Relationship
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin; D010446:Peptide Fragments; D011498:Protein Precursors; C061970:glucagon-like peptide 1 (7-36); D011092:Polyethylene Glycols; D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D018819:Dipeptidyl Peptidase 4