Calhoun Lab Monitoring Membrane Transport
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.