Laura Cooley
 
We are studying a protein known as actin, which is responsible for providing cells with their internal structure (cytoskeletal structure).  This protein polymerizes from a form known as globular actin (G-actin) to form filamentous actin (F-actin).  F-actin filaments are about seven nanometers wide, and can grow quite long.  Like DNA molecules, they carry negative charges.
While actin filaments carry negative charges, under certain conditions they can nevertheless be made to aggregate (or form bundles.)
There are many reasons for studying these phenomena.  For example, the high viscosity of sputum in cystic fibrosis patients is caused in part by aggregation of actin in the sputum.
    •    Why does this happen? 
    •    Can it be reversed? 
    •    How?
To answer these questions requires basic knowledge of how and why bundles form. Currently I am performing a study of how bundle size varies with concentration of added magnesium ions, above threshold concentration. 
To do this, I am using fluorescence microscopy. We measure the fluorescence intensity across a bundle and figure out the relative size from the relative fluorescence intensity.   See images below.
 
Material Sciences and
Physical Chemistry