Physical Chemistry 
 
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 image above.
 
Glênisson de Oliveira
In the de Oliveira group, our main area of research is theoretical chemistry.  Historically, this label is distinct from “computational chemistry” in that the former includes the development of new methods and theories, while the latter consists of the use of existing models to help elucidate practical issues in chemical fields.  In the area of methods development, our recent efforts have been focused on the choice of mathematical functions (basis sets) used in approximate solutions of the Schrödinger equation (ab initio methods).  We have modified existing basis sets to efficiently and accurately determine the infinite basis set limits for physical properties of molecules and molecular clusters.   In one case, our method became part of standard computational chemistry packages, leading to some 300 citations to a single paper.  More specifically, we are interested in models that explicitly account for electrostatic contributions to non-covalent interactions, including the effect of polarizabilities, hyperpolarizabilities, and high order terms of the permanent moment tensor (i.e. beyond dipole moments).  Chemical problems we address involve weak interactions and clustering phenomena for small molecules – such studies are typically put under the umbrella of “physical chemistry,” which is our area of expertise.  Other non-covalent interactions involving metal complexes are also addressed.