Synthetic Bzip Proteins as Targeting Agents for Pdt

Ogawa, Michael

Abstract

The following proposal for a NIH-AREA grant describes a pilot study designed to test the efficacy of utilizing the family of bZIP transcription factors to target photodynamic therapy (PDT) reagents to specific sequences of DNA (i.e. the AP-1 element: 5'-TGAGTCA-3'). In particular, both native and de novo designed bZIP proteins will be derivatized with photoactive metal complexes which have been previously shown to cause DNA damage by either direct photoinduced electron-transfer and/or the photochemical generation of singlet oxygen (1O2). The in vitro DNA recognition properties of these metallopeptides will then be studied by electrophoretic mobility shift assays, as will be their ability to produce site-specific DNA photodamage. Transient absorption and emission lifetime studies will be conducted on these systems to help identify the mechanisms involved in the photolesion process. An advantage in using bZIP proteins as targeting vehicles for PDT reagents is that their recognition elements can be found within a large number of promoters which participate in such important processes as cell differentiation and proliferation. Damage to these sites should be very cytotoxic. An additional advantage in the proposed approach to deliver PDT drugs to specific intracellular targets is that it can, in principle, be used to deliver a wide variety of PDT drugs. It is believed that the work described in this proposal will provide a new opportunity for students at Bowling Green State University to participate in a multi-disciplinary research project which may encourage their interest in pursuing graduate studies in the biomedical sciences. Receipt of this award will also enhance the PI's ability to pursue the goals of this focused pilot-project.