Research

Design of small metalloproteins by miniprotein oligomerization

Research - Marcos R. Conde Gonzalez

Metalloproteins are ubiquitous and essential for all forms of life. The incorporation of a metal center in the protein environment fulfills several purposes. On the one hand, structural, such as in the zinc finger proteins, where the redox inactive Zn(II) serves as a structural element, defining the secondary structure of a relatively small protein domain. On the other hand, the incorporation of redox-active metals, such as nickel, molybdenum, copper, and iron, endows the proteins with novel catalytic activities, unattainable to an all-organic catalyst. In particular, the versatility of copper and iron is remarkable. These metals can participate in electron transfer (cytochromes and blue copper proteins) as well as in small molecule transport (hemoglobin and hemocyanin) and reduction (Cu- and heme-nitrite reductases) and oxidation (cytochrome P450 and LPMO) reactions.

My research focuses on the design and characterization of miniproteins that mimic the properties of natural metalloenzymes. Moreover, I employ protein oligomerization to obtain higher assemblies that incorporate further layers of complexity while remaining attainable by chemical synthesis. I rely heavily on Rosetta® and other protein design tools to obtain the models for further characterization in the lab. As characterization methods, I employ circular dichroism to determine the folding behavior and stability of the proteins both in the apo and holo states and UV-vis and fluorescence spectroscopies, as well as EPR to characterize the metal binding strength, the coordination environment as well as their catalytic competency.

My goal is to obtain small metalloprotein models of natural enzymes which leads us to a better understanding of the underlying mechanism of electron transfer and catalysis and the factors that affect them. This in turn would allow us to find and optimize new bio-based catalysts that have an impact on the various problems that affect modern society such as environmental pollution and green energy sources.