Chemical Tool for Investigating Biological Sulfur and Selenium Species

Sulfur and selenium occupy a unique position at the interface of inorganic chemistry, redox chemistry, and biology, where changes in oxidation state, speciation, and metal coordination can profoundly alter reactivity. Understanding the fundamental chemistry of reactive S and Se species therefore provides a framework for connecting molecular structure and bonding to their roles in complex biological environments. Biological sulfur metabolism is often framed around H2S as both a metabolic product and signaling species. Increasing evidence, however, indicates that persulfides (RSSH) and related dichalcogenides serve as central intermediates in sulfur trafficking, redox buffering, and enzymatic sulfur-transfer reactions. Despite their growing importance, the fundamental chemical properties that govern the reactivity, stability, and biological fate of these species remain poorly defined.

This presentation will highlight recent efforts from our group to prepare and use isolable sulfur and selenium dichalcogenides to establish fundamental structure-reactivity relationships relevant to bioinorganic S/Se chemistry. Examples will include intrinsic dichalcogenide reaction chemistry, synthetic metal-persulfide model complexes, and studies showcasing how coordination to Lewis-acidic metal centers can modulate dichalcogenide electronic structure and reactivity. Together, these studies establish fundamental chemical principles for understanding sulfur and selenium transfer, provide molecular-level insight into metalloenzyme-mediated sulfur trafficking and oxidation pathways, and highlight how coordination chemistry can be used to interrogate the broader chemical landscape of sulfur metabolism.

Speaker: Mike Pluth, University of Oregon