Calhoun Lab Monitoring Membrane Transport

December 18, 2024 by ljudy@utk.edu

The complexity of bacterial membranes facilitates the delicate balance of transporting nutrients while protecting the cell from antibiotics. The Calhoun Lab at the University of Tennessee, Knoxville, specializes in interpreting molecule-membrane dynamics within these microscopic environments using the nonlinear optical technique, second harmonic scattering.

Marea Blake (‘24) was the first author on a recent study where the Calhoun Lab monitored the impact of miltefosine, a drug and membrane disruptor, on living bacterial cells. They were able to observe a localized impact of this molecule. This led to the transport of some small molecules not changing in the presence of this drug while others were altered significantly. Such insight into compounding effects can provide a deeper understanding of drug mechanisms and new directions for adjuvant design. These results were published in RSC Chemical Biology and were accompanied by a cover image.

The lab is continuing to study small-molecule dynamics in bacteria by imaging the impact of membrane heterogeneity on transport behavior, identifying cell envelope contributions. Additionally, they are observing efflux resistance mechanisms after antibiotic incubation, dissecting impacts of the membrane proton motive force, and understanding the change in molecule tilt angles over time. 

This research is possible through funding from a National Institutes of Health (NIH) Maximizing Investigators’ Research Award (MIRA, R35) to Calhoun.

BCMB Support Serves Research, Teaching Missions

December 18, 2024 by ljudy@utk.edu

Support matters, whether it be technical, financial, or through mentoring and guidance. For those of you who continue to support the Department of Biochemistry and Cellular and Molecular Biology (BCMB) in any form, thank you, thank you, thank you! 

In this newsletter, we illustrate how these types of support allow the department to continue its research and teaching missions and to do its part to better serve all Tennesseans. Financial support directly to the department returns on investment in spades, as you will read in the newsletter. You will also meet our newest colleagues, Assistant Professors Martin Engelke and Jie Sun. 

At its core, research and teaching in biochemistry and cellular and molecular biology span the continuum of the structure and function of macromolecules and their interactions to make all cell types and their subcellular components in their amazing diversity. The technological advances of the last decade span an explosion of high-resolution microscopy approaches, a plethora of genomics platforms and related data analyses, as well as leaps in the power of supercomputing, including the rise of artificial intelligence. At the scale at which BCMB research is conducted, instrumentation and analytical approaches matter a lot. In this newsletter, you will read about research conducted in BCMB that perfectly highlights this.

Training in BCMB shapes diverse careers, as you can see in the alumni spotlights at right. It is not uncommon for our graduates—whether with a BS, MS, or PhD—to go on to pharmaceutical and biotech industries. 

As always, please share any comments, suggestions and feedback. Your news is our news, so please share with us! Welcome to the 2025 edition of the newsletter!