We wish to show that gas-phase studies of small metal cluster-biomolecule complexes provide fundamental insights into the mechanism leading to enhanced optical absorption in nanoparticle-biomolecular hybrid systems. Here we present, for the first time, a joint experimental and theoretical study of photoabsorption and photofragmentation of the silver trimer-tryptophan cation complex ([Trp∙Ag3]+). We demonstrate that binding the metal cluster to a biomolecule leads to a remarkably high optical absorption as compared to the bare tryptophan or the [Trp∙Ag]+ complex. As calculations show this arises due to coupling between the excitations in the metallic subunit with a charge transfer excitation to the tryptophan molecule.