Jose F. Cerda, PhD

• BS University of Puerto Rico at Mayagüez 1994 (Chemical Engineering)
• MS University of Puerto Rico at Mayagüez 1997 (Chemistry)
• PhD Michigan State University 2002 (Physical Chemistry)

*SJU undergraduate students in bold.

1. “Extended Scope Synthesis of an Artificial Safranin Cofactor” Gheevarghese Raju, Sunaina Singh, Andrew C. Mutter, Bernard Everson, Jose F. Cerda, Ronald L.Koder. Tetrahedron Letters 2014 (55) 2487-2491.
2. “Heme Peripheral Groups Interactions in Extremely Low-Dielectric Constant Media and their Contributions to the Heme Reduction Potential” Jose F. Cerda*, Mary C. Malloy, Brady O. Werkheiser, Alaina T. Stockhausen, Michael F. Gallagher, and Andrew C. Lawler. Inorganic Chemistry 2014, 53 (1), 182–188 .
3. Electrochemical Determination of Heme-Linked pKas and the Importance of Using Fluoride Binding in Heme Proteins” Jose F. Cerda, Margaret H. Roeder, Danielle N. Houchins, Carmen X. Guzman, Emily J. Amendola, Jacquelyn D. Castorino, and Andrea L. Fritz. Analytical Biochemistry 2013 (443) 75-77.
4. “Spectroelectrochemical measurements of redox proteins by using a simple UV/visisble cell” Jose F. Cerda, Carmen X. Guzman, Haibo Zhang, Emily J. Amendola, Jacquelyn D. Castorino, Nina Millet, Andrea L. Fritz, Danielle N. Houchins, and Margaret H. Roeder. Electrochemistry Communications 2013 (33) 76-79.
5. “A three-dimensional printed cell for rapid, low-volume spectroelectrochemistry” Joseph M. Brisendine, Andrew C. Mutter, Jose F. Cerda, and Ronald L. Koder. Analytical Biochemistry 2013, (439) 1-3.
6. “Manipulating Reduction Potentials in an Artificial Safranin Cofactor” Gheevarghese Raju, Joseph Capo, Bruce R. Lichtenstein, Jose F. Cerda, Ronald L. Koder. Tetrahedron Letters 2012, (53), 1201-1203.
7. “Electrochemical and Structural Coupling of the Naphthoquinone Amino Acid” Bruce R. Lichtenstein, Veronica R. Moorman, José F. Cerda, A. Joshua Wand and P. Leslie Dutton. Chemical Communications 2012,(48) 1997–1999.
8. “Reversible Proton Coupled Electron Transfer in a Peptide-incorporated Naphthoquinone Amino Acid” Bruce R. Lichtenstein, Jose F. Cerda, Ronald L. Koder, P. Leslie Dutton. Chemical Communications 2009, 168–170
9. “Hydrogen Bond-free Flavin Redox Properties: Managing Flavins in Extreme Aprotic solvents” Jose F. Cerda, Ronald L. Koder, Bruce R. Lichtenstein, Christopher C. Moser, Anne F. Miller, P. Leslie Dutton. Organic & Biomolecular Chemistry 2008, 6, 2204-2212.
10. “A Flavin Analogue with Improved Solubility in Organic Solvents” Ronald L. Koder, Bruce R. Lichtenstein, Jose F. Cerda, Anne F. Miller, P. Leslie Dutton. Tetrahedron Letters 2007, 48, 5517-5520.
11. “Structural Specificity in Designed Four alpha-helix Bundles Driven by Buried Polar Interactions” Ronald L. Koder, Kathleen G. Valentine, Jose Cerda, Dror Noy, A. Joshua Wand and P. Leslie Dutton. Journal of the American Chemical Society 2006 (128) 14450-14451.

UV-vis spectroelectrochemistry
The main application in my research lab is UV-vis spectroelectrochemistry. At SJU, I have been able to optimize an electrochemcal setup that I started at UPenn into a robust and powerful technique for the study of redox proteins. The UV-vis spectroelectrochemical setup allows the measurement of the midpoint potential (Em) of a redox compound by using UV-vis spectroscopy. The setup is the culmination of both of my research backgrounds in protein spectroscopy and electrochemistry. The technique consists in providing the cell potential (Eapp), via the use of electrodes, and simultaneously measuring the UV-vis absorption of the redox compound. The absorption of the sample is then plotted versus the applied potential (Eapp) and the Nernst equation is used to determine the Em of the compound. Also, with the Nernst fit, the number of electrons that are involved in the redox reaction can be determined. Further details of this setup and its application to redox proteins can be found in reference 4 of the publication list.

Electrochemical studies of heme-bound fluoride proteins
The UV-vis spectroelectrochemical setup has also been used to establish a method to study the heme cofactor and its surrounding protein structure. Fluoride has been known to bind to many heme proteins in their oxidized state (Fe3+). Past studies of heme-bound fluoride complexes have only focused on the spectroscopic properties of the heme protein in the presence of fluoride. In our research, we measure the Em of heme proteins in the presence of heme-bound fluoride complexes. In myoglobin, the oxidized form contains a water molecule in the sixth ligand position. Addition of fluoride results in the substitution of the water ligand for a heme-bound fluoride ion. The advantage of using fluoride is that it has similar electronic properties as the water ligand; both are high spin ligands that cannot bind to the ferrous heme ion. Therefore, upon comparison between the heme protein without fluoride and with fluoride, any changes in Em can mainly be attributed to changes in the oxidized state (see reference 3 of the publication list).

The study of heme cofactors in aprotic solvents
This research project consists in the study of the electrochemical properties of heme cofactors in aprotic solvent and the effects of proton interactions on the heme reduction potential. One of the most interesting topics in the field of bioenergetics is the proton pump in enzymes such as cytochrome c oxidase and cytochrome bc1. These enzymes utilize redox energy for proton translocation that results in a proton gradient across the mitochondrial membrane. This stored electrochemical energy is then used to form ATP, the energy currency of metabolism. The functioning of the proton pump in CcO is a source of controversy because of its complexity, but it has been suggested that the heme a peripheral groups are involved in the proton pumping mechanism. Heme peripheral groups have also been shown to be involved in various heme-protein interactions in many other proteins.
Quantification of theses interactions is difficult because the protein itself is involved in various interactions (hydrogen bonding, electrostatic attraction/repulsion, pi-pi stacking, and hydrophobic stabilization) with the heme. In order to study a particular interaction, a model heme must be devoid of the other interactions. Quantification can be performed on a heme model compound in an aprotic solvent, such as dichloromethane or benzene, with a ligand that can singularly interact with one of its peripheral groups. The low-dielectric constants of these solvents, 8.9 and 2.3 for dichloromethane and benzene, respectively, make them ideal media to study hemes in because the interior of proteins can have dielectric constant values as low as 2.5 (reference 2 on publication list)

Student Research at SJU
Most of the research in our lab has been carried out by students that got their first independent research experience under the sponsorship of the Summer Scholars Program. Additionally, the Chemistry Department is very supportive of the faculty’s research program and student research