Metal-binding cysteine free peptides

These invention relates to metal-complexing, cysteine-free peptides which may be coupled to an organ-specific probe directly or via a linker and are thus enriched as conjugates specifically in tumors, organs, tissues or centers of inflammation. The organ-specific probes used are, for example, antibodies or part-sequences of antibodies against tumor-associated antigens, e.g. the carcino-embryonal antigen (CEA, which are thus specifically enriched in tumors. The invention also relates to processes for producing the metal-complexing cysteine-free peptides and their conjugates. The present invention also relates to the use of the conjugates as components of a kit for in vivo diagnosis or in vivo therapy and radio-pharmaceuticals containing these conjugates together with radio-isotopes. The organ-specific conjugates are used to image tumors, organs or centers of inflammation.