Ph.D. (2010) University of California, Berkeley

Biological membranes are diverse, complex, and dynamic natural environments. The processes mediated by these environments are essential for life and span from molecular transport to protein function. Given the membrane’s role in mediating the movement of molecules into bacterial cells, new approaches to evaluate its impact are essential for the study and advancement of antibiotics. The Calhoun lab’s interdisciplinary research program specializes in the application and advancement of nonlinear spectroscopy and microscopy techniques for the study of a variety of systems, including bacterial membranes. Our current projects aim to directly probe how the complexity of living bacterial membranes impacts the uptake, transport, localization and efflux of small molecules, including antibiotics. To this end, we are employing the nonlinear optical technique, second harmonic scattering, to quantitatively assess how factors such as small molecule structure, environmental species and membrane composition facilitate or hinder the adsorption and internalization of antibiotics by bacteria.

Facilitating flip-flop: Structural tuning of molecule-membrane interactions in living bacteria

MJ Blake, HB Castillo, AE Curtis, TR Calhoun

Biophysical Journal 122 (10), 1735-1747

Monitoring membranes: The exploration of biological bilayers with second harmonic generation

EF Page, MJ Blake, GA Foley, TR Calhoun

Chemical Physics Reviews 3 (4)

Phosphate ions alter the binding of daptomycin to living bacterial cell surfaces

LN Miller, MJ Blake, EF Page, HB Castillo, TR Calhoun

ACS infectious diseases 7 (11), 3088-3095

Second harmonic generation spectroscopy of membrane probe dynamics in gram-positive bacteria

LN Miller, WT Brewer, JD Williams, EM Fozo, TR Calhoun

Biophysical Journal 117 (8), 1419-1428