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Alexey Silakov, Pennsylvania State University

Title: "Understanding the inner workings of hydrogen-producing enzymes"

Abstract:

The Silakov laboratory research aims to elucidate the fundamental principles governing the control exerted by biological systems over the reactivity of metal complexes within enzymes. We seek to uncover intricate mechanisms by which metal-containing catalytic centers, seemingly analogous in composition, exhibit remarkable variations in their reactivity contingent upon the surrounding protein environment. We employ an extensive repertoire of advanced experimental techniques, including Electron Paramagnetic Resonance and Infrared spectroscopies, (spectro)electrochemistry, and protein film voltammetry. I will present one of our research projects concerning H₂-evolving enzymes called [FeFe] hydrogenases. Their extraordinary catalytic competence renders them highly appealing for utilization in renewable energy applications and biohydrogen generation. Unfortunately, the utility of these enzymes is hindered by their paradigmatic instability under aerobic conditions, constituting a significant impediment to their practical (industrial) exploitation. During this presentation, I will present compelling evidence of a subset of [FeFe] hydrogenases capable of sustained operation in the presence of molecular oxygen. Furthermore, I will discuss our ongoing endeavors to leverage this discovery to establish a proof-of-concept for sustainable photosynthetic H₂ production. In this work, we seek to couple O₂-tolerant [FeFe] hydrogenases with a cyanobacterial photosystem I complex, an approach with potential implications for sustainable, carbon-neutral H₂ production.