Upcoming Seminars

All seminars for the 2020-2021 Academic Year will be held virtually and not on grounds. Friday seminars will be at 3:30pm. 

Fall 2020

Oct
23

Sensing through the Skull: Developing Surface-Enhanced Spatially-Offset Raman Spectroscopy (SESORS) for in vivo Neurochemical Detection

Sensing through the Skull: Developing Surface-Enhanced Spatially-Offset Raman Spectroscopy (SESORS) for in vivo Neurochemical Detection

Dr. Bhavya Sharma | University of Tennessee, Knoxville

Professor Jill Venton

Sensing through the Skull: Developing Surface-Enhanced Spatially-Offset Raman Spectroscopy (SESORS) for in vivo Neurochemical Detection

The brain is a complex organ, with billions of neurons and more than 30 distinct neurochemicals (possibly up to 100), involved in all aspects of a human life, including cognition, movement, sleep, appetite, and fear responses. For some neurological diseases/conditions, changes in neurochemical concentrations could be predictors of early onset disease or disease progression. While there are a variety of sampling techniques which can detect neurotransmitters in biofluids at low concentrations, these techniques often involve multi-step sample preparations coupled with long measurement times, and are not suited for in vivo detection. There is a need for the development of sensors for the detection of neurotransmitters that are selective, rapid, and label-free with little to no sample processing. We focus on the detection of biomarkers for neurological activity in biofluids and through the skull.

Our approach is to apply surface enhanced Raman spectroscopy (SERS), a highly specific and selective vibrational spectroscopy, for the detection of neurochemicals. Raman scattering is an inherently weak phenomenon. We incorporate the electric field generated at the surface of noble metal nanoparticles in our sensors to enhance the weak Raman scattering signal. SERS is surface selective, highly sensitive, rapid, label-free and requires little to no sample processing. We are developing SERS-based sensors for in vitro neurotransmitter sensing at physiologically relevant concentrations in biofluids. For in vivo detection, we combine SERS with spatially offset Raman spectroscopy (SORS), where Raman scattering spectra is obtained from subsurface layers of turbid media.  We demonstrate detection of physiologically relevant concentrations of neurotransmitters in the micromolar (µM) to nanomolar (nM) concentration ranges with SESORS in a brain tissue mimic through the skull.

Dr. Bhavya Sharma | University of Tennessee, Knoxville
Hosted by Professor Jill Venton
Oct
28

Incorporating Metal-Ligand and Metal-Metal Cooperativity into First Row Transition Metal Complexes with Applications in Catalysis

Incorporating Metal-Ligand and Metal-Metal Cooperativity into First Row Transition Metal Complexes with Applications in Catalysis

Dr. Christine Thomas | Ohio State University

Professor Charlie Machan

Incorporating Metal-Ligand and Metal-Metal Cooperativity into First Row Transition Metal Complexes with Applications in Catalysis

 

The formation and cleavage of chemical bonds in catalytic reactions relies on accessible two-electron redox processes that are often challenging for base metals such as first row and early transition metals. Metal-ligand and metal-metal cooperativity provide a potential solution to this challenge by enabling heterolytic bond cleavage processes and/or facilitating redox processes. Both strategies will be discussed, showcasing the many ways that metal-ligand and bimetallic cooperativity can operate and the methods by which cooperativity can be built into catalyst design. A tridentate pincer ligand featuring a reactive N-heterocyclic phosphido fragment is found to be both redox active and an active participant in bond activation across the metal-phosphide bond, with catalytic applications in alkene hydroboration. A tetradentate bis(amido)bis(phosphide) ligand has been coordinated to iron and it has been shown that the resulting complex can activate two σ bonds across the two iron-amide bonds in the molecule without requiring a change in the formal metal oxidation state. In the context of metal-metal cooperativity, phosphinoamide-linked early/late heterobimetallic frameworks have been shown to support metal-metal multiple bonds and facilitate redox processes across a broad range of metal-metal combinations and the resulting complexes have been shown to activate small molecules and catalyze organic transformations.

Dr. Christine Thomas | Ohio State University
Hosted by Professor Charlie Machan
Nov
06

Inspiration from Fluorination:  Chemical Epigenetics Approaches to Probe Molecular Recognition Events in Transcription

Inspiration from Fluorination:  Chemical Epigenetics Approaches to Probe Molecular Recognition Events in Transcription

Dr. William Pomerantz | University of Minnesota

Professor Marcos Pires

Inspiration from Fluorination:  Chemical Epigenetics Approaches to Probe Molecular Recognition Events in Transcription

 

Protein-protein interaction inhibitor discovery has proven difficult due to the large surface area and dynamic interfaces of proteins.  To facilitate the early lead discovery rate, I will first describe a rapid protein-based 19F NMR method for detecting protein-ligand interactions by screening low complexity molecules (fragments), drug-like molecules, and peptidomimetics. We have tested the sensitivity, accuracy, and speed of this method through screening libraries of small molecule fragments.  The advantages of using 3D-fragments for discovery of more selective hits for bromodomain-containing proteins will be specifically highlighted. In the second part of the talk, I will describe improvements in our method for the field of epigenetics targeting bromodomain and extra-terminal (BET) family proteins. These studies have led to a selective inhibitor for the first bromodomain of BRD4. Structure-based design has identified several new design rules for maintaining selectivity and potency.  Cellular efficacy in cancer and inflammatory model systems using this novel BRD4 inhibitor will be briefly described.  Finally, development of a new heterocyclic scaffold for the second bromodomain of BRD4 will be highlighted. The speed, ease of interpretation, and low concentration of protein needed for binding experiments affords a new method to discover and characterize both native and new ligands for bromodomains and may find utility in the study of additional epigenetic “reader” domains.

Dr. William Pomerantz | University of Minnesota
Hosted by Professor Marcos Pires
Nov
13

Harnessing RNA Regulation to Direct Protein Evolution and Control Mammalian Gene Expression

Harnessing RNA Regulation to Direct Protein Evolution and Control Mammalian Gene Expression

Dr. Bryan Dickinson | University of Chicago

Professor Clifford Stains

Harnessing RNA Regulation to Direct Protein Evolution and Control Mammalian Gene Expression

 

I will present two recent technologies our group has developed that harness RNA regulation – one for basic science purposes and one for therapeutic development. First, I will describe new methods that use our RNA polymerase-based biosensors to harness evolution in order to probe the emergence of “selectivity” between biomolecular interfaces, in particular, protein-protein interactions (PPIs). Using a combination of high-throughput biochemical methods, ancestral reconstruction, and a new rapid evolution technology, we developed a model system involving the BCL-2 family of apoptotic regulatory proteins to probe fundamental evolutionary questions about PPIs and how selectivity (or not) emerges between them. In the second half of the talk, I will discuss therapeutic opportunities involving RNA regulation and “epitranscriptomics”. While RNA regulation offers exciting opportunities to create genetic therapies that are reversible and tunable, most current approaches rely on large, microbially-derived systems that pose clinical challenges. We developed the CRISPR/Cas-inspired RNA targeting system (CIRTS), a new protein engineering strategy for constructing programmable RNA regulatory systems entirely from human protein parts. The small size and human-derived nature of CIRTS provides a less-perturbative method for fundamental studies as well as a potential strategy to avoid immune issues when applied to epitranscriptomic therapies.

Dr. Bryan Dickinson | University of Chicago
Hosted by Professor Clifford Stains

Spring 2021

Jan
22

Dr. Ashleigh Theberge | University of Washington

Dr. Ashleigh Theberge | University of Washington

Professor Rebecca Pompano
Hosted by Professor Rebecca Pompano
Feb
05

No Seminar: Candidacy Exams

No Seminar: Candidacy Exams

Feb
12

Dr. Susanna L. Widicus Weaver | University of Wisconsin-Madison

Dr. Susanna L. Widicus Weaver | University of Wisconsin-Madison

Professor Eric Herbst
Hosted by Professor Eric Herbst
Feb
19

Dr. Jillian Dempsey | University of North Carolina

Dr. Jillian Dempsey | University of North Carolina

Professor Brent Gunnoe
Hosted by Professor Brent Gunnoe
Mar
05

No Seminar: Friday before Spring Break

No Seminar: Friday before Spring Break

Mar
12

No Seminar: Spring Break

No Seminar: Spring Break

Mar
19

Graduate Visitation Weekend 3/18 - 3/19

Graduate Visitation Weekend 3/18 - 3/19

Mar
24

Dr. Frank Bennett | Ionis Pharmaceuticals

Dr. Frank Bennett | Ionis Pharmaceuticals

Dr. Frank Hecht
Hosted by Dr. Frank Hecht
Mar
26

Dr. Robert Kennedy | University of Michigan

Dr. Robert Kennedy | University of Michigan

Professors Rebecca Pompano and Jill Venton
Hosted by Professors Rebecca Pompano and Jill Venton
Apr
02

Dr. Ying Wang | University of North Carolina - Wilmington

Dr. Ying Wang | University of North Carolina - Wilmington

Professor Huiwang Ai
Hosted by Professor Huiwang Ai
Apr
16

ACS Poster Session

ACS Poster Session

Apr
23

Dr. Linda Hsieh-Wilson, CalTech | Burger Lecture

Dr. Linda Hsieh-Wilson, CalTech | Burger Lecture

Professor Ken Hsu
Hosted by Professor Ken Hsu