PEGylation of cholecystokinin prolongs its anorectic effect in rats.
The anorectic compound CCK-9 was coupled to polyethylene glycol 5 kDa, 10 kDa, 20 kDa and 30 kDa, under different reaction conditions. Conjugates were purified by HPLC and characterized by MALDI-TOF MS. A 96% PEGylation yield was obtained in buffer pH 7.5 after 6h reaction at 20 degrees C. The anorectic activity was tested in vivo in rats. A single bolus intra-peritoneal injection of non-modified CCK-9 resulted in a significant initial food intake reduction 30 min after food presentation (87% compared to paired control group). When PEG-CCK-9 conjugates modified with polymers of molecular weight up to 20 kDa were injected, lower but statistically significant initial food intake reductions were obtained (76% for PEG 10 kDa-CCK-9 conjugate compared to control group). The cumulative food intake reduction of non-modified CCK-9 is normalized within 1-2h, whereas the PEG-CCK-9 molecules showed a prolonged anorectic activity lasting for 6h for PEG 5 kDa-CCK-9; 23 h for PEG 10 kDa-CCK-9 and between 8h and 23 h for PEG 20 kDa-CCK-9. For PEG 30 kDa-CCK-9 conjugate, neither an initial nor a cumulative FI reduction was observed. PEG-CCK-9 conjugates show a significantly prolonged anorectic activity in comparison to the non-modified peptide. This effect is most evident for the PEG 10 kDa-CCK-9 conjugate.
León-Tamariz
Fabián
F
Laboratory of Toxicology and Bromatology, Faculty of Pharmaceutical Sciences, Katholieke Universiteit Leuven, Leuven, Belgium.
Verbaeys
Isabelle
I
Van Boven
Maurits
M
De Cuyper
Marcel
M
Buyse
Johan
J
Clynen
Elke
E
Cokelaere
Marnix
M
D000818:Animals; D000855:Anorexia / Q000139:chemically induced / Q000503:physiopathology; D002766:Cholecystokinin / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004355:Drug Stability; D004435:Eating / Q000187:drug effects* / Q000502:physiology; D007274:Injections, Intraperitoneal; D008297:Male; D015394:Molecular Structure; D008970:Molecular Weight; D010446:Peptide Fragments / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013329:Structure-Activity Relationship; D013997:Time Factors
D010446:Peptide Fragments; C053399:cholecystokinin 9; D011092:Polyethylene Glycols; D002766:Cholecystokinin