Chemistry Colloquium Program

Frank R. Fronczek, Ph.D.

Facility Manager
X-ray Crystallography Facility
Louisiana State University

 

"A Half Century of Crystallography and Bleeding Purple and Gold"

The history of the Chemistry Department single crystal X-ray facility will be described, with a decade-by-decade emphasis of who the major users have been and how crystal structure analysis has been essential to their research. Extracurricular activities by the director of the facility, particularly humorous ones, will also be discussed, along with details of his crystallographic career.

Host: Sviatoslav Baranets

Víctor García-López, Ph.D.

Assistant Professor
Department of Chemistry
Louisiana State University

"Molecular Machines and Switches for Controlling Membrane Function and Biological Response"

Molecular machines and switches are powerful tools for controlling lipid membrane properties. They convert external energy inputs, such as light, into conformational changes and molecular motion, which alter the physical properties and function of the surrounding lipid bilayer. Our group at LSU focuses on the design and synthesis of light-activated mechanically interlocked molecules, such as rotaxanes, and on establishing how their structure and dynamics translate into membrane and biological function.

In this colloquium, I will describe how we design rotaxanes that incorporate into lipid bilayers and modulate membrane tension and permeability when exposed to light. We leverage these changes to achieve controlled cargo release from lipid vesicles and to modulate voltage-driven ion transport across droplet interface lipid bilayers. Our photoswitchable rotaxanes allow optical control of membrane structure and electrical properties, providing an orthogonal handle to reprogram the membrane’s energy landscape and switch between two distinct neuromorphic behaviors, memristance and memcapacitance.

I will also describe how these rotaxanes can be incorporated into biological membranes. These rotaxanes are effective antimicrobials against antibiotic-resistant bacteria, including the ESKAPE pathogens A. baumannii, P. aeruginosa, and S. aureus, while exhibiting low toxicity toward red blood cells. Importantly, I will show how rotaxane functionalization may enable access to distinct antibacterial mechanisms of action.

Our work demonstrates how fundamental concepts in supramolecular chemistry and photochemistry can be integrated with membrane biophysics and microbiology to develop functional molecular systems that address interdisciplinary challenges at the interface of chemistry, materials science, biology, and medicine.

Hosts: David Spivak

 

 

Fabrizio Donnarumma, Ph.D.

Director
Mass Spectrometry Facility & The Shared Laboratory for Macro and Bio-Macromolecular Research (SLMBR)
Louisiana State University

 

Host: Gerald Schneider

Yi Cui, Ph.D.

Fortinet Founders Professor
Professor of Materials Science and Engineering
Stanford University

 

A101 Annex Auditorium

Reception Following

 

Hosts: Graça Vicente & Gerald Schneider

 

 

Thomas K. Weldeghiorghis, Ph.D.

Director, NMR Facility
Department of Chemistry
Louisiana State University

 

Host: Gerald Schneider

 

 

 

 

Jason LeJeune, Ph.D.

Environmental Health & Safety Manager
LSU Environmental Health & Safety

 

Host: David Spivak

Christopher Jaroniec, Ph.D.

Arts and Sciences Distinguished Professor
Department of Chemistry
Associate Dean for Research and Creative Inquiry
The Ohio State University

 

Host: Pu Duan

 

 

Jim Boncella, Ph.D.

Professor
Department of Chemistry
Washington State University

 

Host: Clifton Wagner

 

 

 

 

 

 

 

 

 

 

Jeremiah A. Johnson, Ph.D.

A. Thomas Guertin Professor of Chemistry
Associate Department Head for Research & Administration
Department of Chemistry
Massachusetts Institute of Technology

Host: Semin Lee

Alison Fout, Ph.D.

Professor
Associate Head for Graduate Studies
Davidson Chair in Science
Department of Chemistry
Texas A&M University

 

Host: Noémie Elgrishi

Valerie Pierre, Ph.D.

Professor
Director - NSF Center for Aqueous Supramolecular Chemistry
Department of Chemistry
University of Utah

 

Host: Noémie Elgrishi

Timothy Warren

Professor and Chair
Department of Chemistry
Johns Hopkins University

 

Host: Clifton Wagner