Tuftsin receptor-binding peptide labeled with technetium: Chemistry and preliminary in vitro receptor-binding study

The Tc-99m complex of dimethylglycyl-L-seryl-L-cysteinyl(acm)-glycl-L-threo nyl-L-lysyl-L-prolyl-L-prolyl-L-arginine (RP128) is a radiopharmaceutical d esigned for imaging sites of inflammation. RP128 and its rhenium(V) and tec hnetium(V) oxo complexes were prepared and characterized by HPLC and variou s spectroscopic techniques. Analysis of RP128 showed that the attachment of the dimethylglycyl-L-seryl-L-cysteinyl-glycine sequence and the coordinati on of it to a TcO3+ core did in not affect the threonyl-L-lysyl-L-prolyl-L- prolyl-L-arginine (TKPPR) portion of the molecule aqueous solution.