Supramolecular Binding of Cationic Porphyrins on a Filamentous Bacteriophage Template: Toward a Noncovalent Antenna System

Here we describe a noncovalent approach based on the interaction between the water-soluble cationic trans-(N-methylpyridinium-4- yl)diphenylporphyrin (t-H2Pagg) and M13 and some genetically modified strains . The latter two structurally differ from wild-type M13 (wt) for an insert of 13-15 amino acids in the N-terminal region of g8p, which is exposed to the solvent, bearing one (8M) or three (MP14) Trp residues. We anticipate that, depending on the nature of the mutants, different extent of resonant energy transfer (RET) from the external Trp residues of the capsid to the interacting porphyrins can be evidenced. This is a prerequisite for designing new efficient artificial antenna systems.