title: Structural study by NMR of an oxorhenium-RGD decapeptide complex for application in radiotherapy.
abstract: The decapeptide Arg-Gly-Asp-Ser-Cys-Arg-Gly-Asp-Ser-Tyr, which contains two Arg-Gly-Asp (RGD) moieties in its sequence, has been successfully labeled with radioactive rhenium (Re-188) yielding a single, stable oxorhenium complex. This complex is being evaluated for possible application in oncology as a target-specific radiotherapeutic agent, because its radioactive technetium-99m analogue has already been applied for the scintigraphic detection of malignant melanoma in humans. For structural characterization purposes, the complex of the decapeptide was synthesized at the macroscopic level using nonradioactive rhenium (Re-185/Re-187). NMR and mass spectral analysis of the nonradioactive oxorhenium complex revealed that the decapeptide coordinates to the oxorhenium core through the N(amide) of Asp3, the N(amide) of Ser4, and the N(amide) and S(thiolate) atoms of Cys5 to form a complex of the ReO[N(3)S] type.
authors.affiliation: Institutes of Radioisotopes & Radiodiagnostic Products and Biology, National Centre for Scientific Research Demokritos, 153 10 Athens, Greece.
authors.forename: Basil
authors.initials: B
authors.lastname: Costopoulos
authors.forename: Dimitra
authors.initials: D
authors.lastname: Benaki
authors.forename: Maria
authors.initials: M
authors.lastname: Pelecanou
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Mikros
authors.forename: Chariklia I
authors.initials: CI
authors.lastname: Stassinopoulou
authors.forename: Alexandra D
authors.initials: AD
authors.lastname: Varvarigou
authors.forename: Spyridon C
authors.initials: SC
authors.lastname: Archimandritis
mesh_terms: D000818:Animals; D004353:Drug Evaluation, Preclinical; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D051379:Mice; D008956:Models, Chemical; D008958:Models, Molecular; D009842:Oligopeptides / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D011868:Radioisotopes; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D011878:Radiotherapy; D012211:Rhenium / Q000737:chemistry*; D014018:Tissue Distribution
chemical_list: D009842:Oligopeptides; D009942:Organometallic Compounds; D011868:Radioisotopes; D019275:Radiopharmaceuticals; D012211:Rhenium