Labeling cyclic glycoprotein IIb/IIIa receptor antagonists with 99mTc by the preformed chelate approach: effects of chelators on properties of [99mTc]chelator-peptide conjugates.
Several cyclic GPIIb/IIIa receptor antagonists were labeled with 99mTc by the preformed chelate approach using chelators such as H4L1 [4,5-bis(mercaptoacetamido)pentanoic acid], H4L2 [3,4-bis-(mercaptoacetamido)benzoic acid], H3L3 [2-(mercapto)ethylaminoacetyl-L-cysteine], H4L4 [N-(mercaptoacetyl)glycylglycylglycine], H4L5 [N-[2-(mercapto)propionyl]glycylglycylglycine], and H4L6 [N-[2-(mercapto)propionyl]glycylglycyl-gamma-aminobutyric acid]. In this approach, the [99mTc]chelator complexes are formed first, followed by the activation of the carboxylic group on the complex by formation of its tetrafluorophenol (TFP) ester and the conjugation of the TFP ester with an amino group of a cyclic GPIIb/IIIa receptor antagonist. The 99mTc-labeled cyclic GPIIb/IIIa receptor antagonists were characterized by radio-HPLC (high-performance liquid chromatography); differences in lipophilicity of the [99mTc]chelator-peptide conjugate are attributable to the effects of both the cyclic peptide and the chelator.
Liu
S
S
Radiopharmaceuticals Division, DuPont Merck Pharmaceutical Company, North Billerica, Massachusetts 01862, USA.
Edwards
D S
DS
Looby
R J
RJ
Poirier
M J
MJ
Rajopadhye
M
M
Bourque
J P
JP
Carroll
T R
TR
D002614:Chelating Agents / Q000138:chemical synthesis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D007553:Isotope Labeling; D015394:Molecular Structure; D009842:Oligopeptides; D010456:Peptides, Cyclic / Q000737:chemistry*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*; D013670:Sodium Pertechnetate Tc 99m
D002614:Chelating Agents; D009842:Oligopeptides; D010456:Peptides, Cyclic; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; C099250:cyclic (arginyl-glycyl-aspartyl-phenylalanyl-lysyl); C047981:arginyl-glycyl-aspartic acid; D013670:Sodium Pertechnetate Tc 99m