Dissertations, Theses, and Capstone Projects

Date of Degree


Document Type


Degree Name





Ronald L. Koder

Subject Categories

Biochemistry | Biophysics


Charge Separation, Four helix bundle, Photosynthesis, Protein Design, Quinone, Zinc Phthalocyanine


The ever-increasing demand for cheap, plentiful energy to fuel the needs of a growing population requires research into alternative clean energy. Solar irradiation has the potential to power the planet many times over; the challenge is efficient capture and conversion of this energy source. Nature has already solved this problem with photosynthesis, which harvests solar irradiation converting it to stored chemical energy and is the source of the energy for life. The goal of my dissertation is to use de novo designed protein to mimic the charge separation system in photosynthesis. A stable protein scaffold will be designed and used to position photoactive cofactors at predetermined distances to yield a high efficient charge separation domain. The creation of a simple single chain four helix bundle protein capable of binding two to three distinct cofactors for use as a light-activated charge separation domain is described. This protein was de novo designed using biologically derived binary patterning with metal ligand coordination and cysteine modification to control cofactor placement. The use of a heme and zinc phthalocyanine cofactors allow for simple bis-histidine and mono-histidine binding sites as the differentiating factor positioning and the quinone is positioned using cysteine mutations. The domain has been expressed and combined with cofactors and biophysically characterized and preliminary data on electron transfer have been obtained.