Fluorescence probe for the QB-binding site

Information about the quinone binding site in photosynthetic reaction centers have been gathered using a wide number of flash-induced spectroscopies. This allowed to collect several details on the semiquinone/binding site interactions. The same type of information for the oxidized form are generally inferred indirectly since the quinone results silent to the majority of these techniques. Here is presented a quinone, remarkably fluorescent in the oxidized form, that binds to the protein accepting electrons (see figure). The preliminary data for its use as a probe for the QB-binding site in the dark are reported.