title: Chemical polysialylation: design of conjugated human oxyntomodulin with a prolonged anorexic effect in vivo.
abstract: Recombinant gut hormone oxyntomodulin (OXM) is known to act as a satiety signal in human subjects and has therapeutic potential as an appetite controlling agent. The only form of this hormone that has a prospective use is a modified one, because native OXM has a very short half-life in vivo. Conjugation of OXM and the natural hydrophilic polymer polysialic acid (PSA) may significantly improve its half-life. Chemical polysialylation in vitro was used to create a long-acting form of OXM, the polysialic acid-oxyntomodulin (PSA-OXM) conjugate. The conjugation site was identified using mass shift comparative analysis of Asp-N proteolytic digests. The anorexic effect of the conjugate was tested on the lean, fasted mouse model. A two-stage purification technique was developed to obtain a homogeneous PSA-OXM conjugate, suitable for in vivo testing. The N-terminal backbone primary amino group was found to be the only point of conjugation. The conjugate obtained was resistant to the DPP-IV protease. A single injection of PSA-OXM at 15 μmol/kg dose was sufficient to maintain a steady decrease in food consumption for 8 h (P < 0.05). The length of the anorexic effect achieved is comparable to other long-acting derivatives of OXM but it requires a much higher dose for administration. It is expected that site-directed attachment of the PSA chain to the inner residues of OXM, away from the site of interaction with receptors, would produce a compound with a higher specific activity but comparable stability in the bloodstream. The conjugation technique used may be used to create OXM derivatives and other related hormones to obtain long-lasting variants, with improved suitability for clinical use.
authors.affiliation: Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry RAS, 117971 Moscow, Russia. ptichman@gmail.com
authors.forename: Ivan
authors.initials: I
authors.lastname: Vorobiev
authors.forename: Viktor
authors.initials: V
authors.lastname: Matskevich
authors.forename: Sergey
authors.initials: S
authors.lastname: Kovnir
authors.forename: Nadezhda
authors.initials: N
authors.lastname: Orlova
authors.forename: Vera
authors.initials: V
authors.lastname: Knorre
authors.forename: Sanjay
authors.initials: S
authors.lastname: Jain
authors.forename: Dmitry
authors.initials: D
authors.lastname: Genkin
authors.forename: Alexandre
authors.initials: A
authors.lastname: Gabibov
authors.forename: Anatoly
authors.initials: A
authors.lastname: Miroshnikov
mesh_terms: D000818:Animals; D001067:Appetite Depressants / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism; D015195:Drug Design; D004435:Eating / Q000187:drug effects*; D006001:Glycoconjugates / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology; D006207:Half-Life; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D053772:Oxyntomodulin / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology; D010446:Peptide Fragments / Q000032:analysis; D059748:Proteolysis; D012794:Sialic Acids / Q000737:chemistry*
chemical_list: D001067:Appetite Depressants; D006001:Glycoconjugates; D053772:Oxyntomodulin; D010446:Peptide Fragments; D012794:Sialic Acids; C021319:polysialic acid; C042807:DPP4 protein, human; D018819:Dipeptidyl Peptidase 4