Representative research topics of graduate students in the
biophysics group
Sreeja Asokan (graduate student, Superfine group):
Molecular Motors as transport systems: motility and control. One of the central themes of nanotechnology
is the scaling down of electromechanical devices or machines to the molecular
scale. Advancement in the fields of microelectronics and microfluidics has influenced the development of
miniaturized devices, where all necessary parts and methods to perform a
chemical analysis are integrated. These micro total analytical systems (m-TAS)
will function as integrated sensing, actuating and synthesizing systems, with
various uses. Development of such lab-on-a-chip requires integration of microsensors and microactuators
on a single chip. This becomes challenging due to the lack of actuating
structures with dimensions less than a micron. I wish to pursue this goal with the help of nanomachine
systems that nature has already created: “biomotors”
or “molecular motors”. More about Sreeja’s research…
David Bostick
(graduate student, Berkowitz
group): Molecular dynamics
of cell membranes. The membranes of modern cells serve many roles outside
that of a simple barrier. They are not simply aggregates of amphipathic
lipids, but are mosaics containing multiple molecular components. My research
is aimed at studying the behavior of ions and water at the biomembrane/water
and biomembrane/electrolyte interface and the
mechanism of ion transport across membranes by proteins via MD simulation
methods. I am specifically interested in the chloride pump, halorhodopsin,
and the chloride channel, ClC. More about David’s research…
Atsuko Negishi
(graduate student, Superfine
group): Biophysics of the viral-cell membrane interface.
A virus infection begins with the virus binding to the cell surface. Understanding this interaction is of interest
for its application in fields such as gene therapy, drug delivery, anti-viral
drug development and biosensors. In
collaboration with UNC Gene
Therapy Center
and School of Pharmacy,
I am specifically looking at the interaction between human parvovirus adeno-associated virus (AAV), a potential viral vector, and
heparan sulfate proteoglycan
(HSPG), a cell surface receptor. More about the
Superfine group…
Alena M. Lieto (graduate
student, Thompson
group): Spectroscopy of biological matter. Total internal
reflection excitation used in combination with fluorescence correlation
spectroscopy (TIR-FCS) is a method for characterizing the dynamic behavior and
absolute concentrations of fluorescent molecules near or at the interface of a
planar transparent substrate and a solution.
As individual molecules diffuse through the observation volume, and bind
to or dissociate from sites on the surface, the fluorescence intensity
fluctuates with time. These fluctuations
are monitored to obtain information about the concentration, diffusion, and
binding characteristics of the molecules. I recently demonstrated for the first
time the use of TIR-FCS for examining the interaction kinetics of fluorescent ligands in solution which specifically and reversibly
associate with receptors in substrate-supported planar membranes. More
about the Thompson group…
Doug King (graduate student, Tiesinga
group): Coding of visual information in visual cortex.
The visual information that enters the eye is represented as spatially
patterned electrical activity in the visual cortex. Neurons in visual cortex
become only active when a particular location of the visual field is stimulated
and when the stimulus has a particular orientation. My research is concerned
with determining what features (orientation and so on) are mapped on the visual
cortex.
More about the Tiesinga
group…
