Surfactants
Surfactants are a class of molecules characterized by a hydrophobic
(water hating) region and a hydrophilic (water loving) region
in the same molecule.
Figure 1: Sodium dodecylsulfate (SDS). Hydrogen
atoms not shown for clarity.
 |
| Janna Register is working with Dr. Chrystal
Dawn Bruce investigating minor groove binding of potential
cancer drugs in DNA. |
A common surfactant in sodium dodecyl sulfate
(sometimes called sodium lauryl sulfate) shown below. Check
the back of your shampoo bottle tomorrow morning – it
is probably one of the first few ingredients.
When enough surfactants are in a solution of
water, they collect themselves into aggregates known as micelles.
Figure 2: Micelle cross section (above) and exterior (below).
Surfactants work so well at removing dirt because dirt dissolves
in the hydrophobic region of the micelle and is washed away
by the shower or your washing machine.
Surfactants are also used in medicinal applications such
as drug delivery and in industrial applications such as polymer
manufacturing. My studies of surfactants propose to answer
questions such as 1) how the structure of the surfactant impacts
the shape and size of the resulting micelle, 2) how the interaction
of water and counterions affect the stability of the micelle,
and 3) what are the physical properties of the different regions
of the surfactant interior?
Polyamide binding to the DNA minor groove
I have recently begun a collaboration with the Moses Lee
group at Furman University in studies of polyamides that bind
to the minor groove of DNA. The application of this research
is in the treatment of certain drug-resistant cancerous tumors.
Figure 3: Small molecule (gray) bound to DNA
double helix. This particular small molecule is a polyamide
(pyrrole – imidazole - pyrrole).
Molecular Dynamics
In both of these projects, we study the structure and dynamic
behavior of molecules using the computational technique of
molecular dynamics (MD) simulations. MD is based on the application
of Newton’s laws of motion to the inter- and intramolecular
interactions of molecules. The mathematical modeling of bond
stretching, bending, and rotation is coupled with non-bonded
electrostatic and steric interactions to give a picture of
how a molecule would behave over time acting under certain
forces. Click here
for a great graphical representation of these types of motion.
We use the commercial software package, AMBER,
to model our systems.
Recent Publications
“Book Review: Kitchen Chemistry by Ted Lister, with Heston
Blumenthal” Bruce, Chrystal D. J. Chem. Educ. 2007, 84, 41.
" ‘Partial derivatives: Are you kidding?’ - Teaching thermodynamics
using Virtual Substance” Solicited by and submitted to the American
Chemical Society Symposium Series based on the symposium entitled
"Physical Chemistry Curriculum Reform Update: Where Are We Now and
Where Are We Going?" (2007)
“Physical and Structural Basis for the Strong Interactions of the
-ImPy-Central Pairing Motif in the Polyamide, f-ImPyIm” Karen L.
Buchmueller, Suzanna L. Bailey, David A. Matthews, Zarmeen T. Taherbhai,
Janna K. Register, Zachary S. Davis, Chrystal D. Bruce, Binh Nguyen, W.
David Wilson, Caroline O’Hare, John A. Hartley and Moses Lee.
Biochemistry 2006, 45, 13551-13565.
“Molecular Dynamics Simulation Of Sodium Dodecyl Sulfate: The Behavior
of Water”, Chrystal D. Bruce, Max L. Berkowitz, Lalith L. Perera, and
Malcolm D.E. Forbes, Journal of Physical Chemistry B, 2002, 106, 10902.
“A Molecular Dynamics Simulation Of Sodium Dodecyl Sulfate Micelle in
Water : Micellar Structural Characteristics and Counterion
Distribution”, Chrystal D. Bruce, Max L. Berkowitz, Lalith L. Perera,
and Malcolm D.E. Forbes, Journal of Physical Chemistry B, 2002, 106, 3788.
We should probably update our photos, since the students on the web page
graduated 2 years ago. Should we schedule a time for that? I will ask
Dr. Thomas to send an electronic copy of an updated list of our recent
graduates too.