About the Seminar
Essential metal ions like zinc, copper, and iron have a broad range of signaling, stabilizing, and catalytic functions across all living systems. The gut microbiota typically acquires these metals through the host diet but must be able to adapt to dietary fluctuations. Many studies link changes in available metal nutrients to alterations in bacterial colonization, pathogen resistance, and gut microbiota community composition but the underlying mechanisms remain unclear. Our research program revolves around elucidating fundamental molecular mechanisms by which metals affect the microbiota. This talk will focus on our efforts to develop metal ion biosensors for illuminating metals within complex bacterial communities. We are investigating a series of cofactor-based fluorescent proteins that emit wavelengths ranging from green to the near-infrared and which, unlike green fluorescent proteins and their variants, do not rely on oxygen. I will cover how our group is re-engineering these proteins to develop novel sensors for zinc and copper. Application of these sensors to live bacteria and opportunities for their use in gut microbiota models will be discussed. I will also present our progress investigating how metal ions affect growth and cell interactions of the Lactobacillaceae family of bacteria, which are crucial members of the gut microbiota.
About the Speaker
Melissa was born in East Haven, Connecticut, and earned her B.S. in Chemistry from the University of Connecticut. While there, she carried out undergraduate research with Prof. Isabelle Lagadic and Prof. Christian Brückner. Melissa earned her Ph.D. in 2013 from the University of Michigan, where she worked with Prof. Vincent Pecoraro on designing dual site metallopeptides for structural stabilization and hydrolytic catalysis. As part of the NIH Chemistry Biology Interface Training Program, she took a brief research sabbatical with Prof. Fraser Armstrong at Oxford University where she carried out electrochemical studies on copper-binding peptides. In 2013, Melissa joined Prof. Stephen Lippard’s lab at MIT as an NIH Postdoctoral Fellow where she developed synthetic and hybrid synthetic-protein fluorescent zinc sensors. Since beginning her independent career at the University of Houston in 2017, Melissa and her research team have focused on developing new biochemical tools for investigating the mechanisms by which metal ions affect the gut microbiota. Her work has been recognized with the NIH R35 MIRA and NSF CAREER awards.