Toxicity of streptavidin is derived from its exceptionally high binding affinity for an essential prosthetic group, D-biotin.

In a preferred embodiment, a radiopharmaceutical precursor is bound to a polymeric support via a prosthetic group comprising an alkenyl-tin bond.

The present invention relates to a method for the display of recombinant functional polypeptides containing a prosthetic group and/or plurality of subunits on the surface of a host cell using the transporter domain of an autotransporter.

Said preparation has an efficient modified copper-binding protein content, the prosthetic group copper having been extracted by a prior exchange reaction or said proteins being produced by copper-free recombination.

Pantothenic acid is required for the synthesis of the prosthetic group of acyl carrier protein necessary for the synthesis of fatty acids in the cytoplasm.