St. Olaf College Chemistry
Department
2003 Summer Research
Program
Research
Opportunities with Bob Hanson
Probably you have seen the new nuclear magnetic
resonance (NMR) spectrometer in what used to be our stockroom on the third
floor of the Science Center. This coming summer will be an opportunity for
one or two students with a computer science/instrumental analysis interest
to work in my group designing a totally new way of carrying out NMR experiments.
This is work started last summer by Gregg Sydow, Stephanie Skladzien, and
Mike Purnell. The idea is to build a web interface
that will allow student "experimentalist teams" to design and run NMR experiments
using a robotic interface from a simple web browser. Sound interesting? We've
done enough development to prove this possible, and now the job will be to
really make it happen. Optimally, if you have some computer programming experience
(JavaScript or HTML, for example) you will be ahead of the game, but I'd
be happy getting you going from scratch if that interests you. There will
be plenty to do that does not involve programming, like designing and testing
the interface, writing web-based materials that describe experiments and
show how to do things, and basically just discovering all of the amazing
things that this new instrument will do. Feel free to stop by and let me
give you a demo. Or visit http://www.stolaf.edu/people/hansonr/nmr/24-7 for an idea of what we're
up to. I guarantee that by the end of the summer you will have learned much
about the "behind-the-scenes" workings of the web as well as one of the most
advanced NMR spectrometers in the world. (If you have an interest in this
as an independent study project during second semester, that could be arranged
as well.)
Research
Opportunities with Paul Jackson
During the summer of 2003 there are numerous opportunities
for interested students to work with me on projects related to separation
science, environmental analysis, and synthesis. Project
1: Pharmaceuticals and personal-care products
contain numerous chemicals designed to illicit specific biological responses. What happens to these unmetabolized or unreacted materials
after we "flush" them down the drain? This project
will go "fishing" for these chemical species in an area of the Cannon River
downstream from the Northfield Wastewater Treatment facility – building on
method development work of the previous students. Our
biggest question right now is “What substances are present in the Cannon
River?” Secondary, is “What is the source of the contamination?” Project 2: Wetlands play
a vital role in the natural world; they provide an excellent water filtration
system and a bridging habitat for both aquatic and terrestrial species. Work on this project focuses on the development of analysis
methods in which organic components in wetland waters may be surveyed and
quantitated. Complexities abound when analyzing natural
samples; the sampling protocol as well as the sample matrix provide challenges
to be overcome. Samples will be taken from the Skoglund
wetland, the city of Northfield, and throughout Rice County. Project 3: Reversed-phase liquid chromatography
(RPLC) is used in over 2/3 of all liquid chromatographic separation protocols. The chemical and physical processes that result in a RPLC
separation are not completely understood. Using previous
experiment results from stationary phases containing embedded polar groups,
we will design experiments to study the behavior of these stationary phases
in purely aqueous mobile phase systems. Additionally,
we may chemically graft a stationary phase ligand onto porous silica particles
to create a different type of stationary phase material for study.
Organometallic
Chemistry of Molybdenum: Gary Miessler
My main research interests
are in organometallic chemistry. Primarily I would
like to develop syntheses of new compounds of molybdenum that contain dithiolene
ligands in addition to organic ligands such as CO and eta5-C5H5. Some important molybdenum- and tungsten-containing enzymes
have dithiolene ligands, and I hope to synthesize compounds that might serve
as models for the metal sites in such enzymes. In
addition, I am interested in testing new ways to prepare transition metal
complexes of the now well-known buckminsterfullerene (C60, alias
“buckyball”) using both thermal and photochemical methods.
In the laboratory, students participating in this
work will gain experience in vacuum line synthesis and purification techniques
beyond the scope of our regular synthesis laboratory courses. Students will also use a variety of instruments, especially
the NMR, IR, and UV-vis, and will perform web-based searches of the chemical
literature. Opportunities to use our CAChe workstations
for chemical calculations on the molecular orbitals of these types of metal
complexes will also be included in this project.
Biochemistry research opportunities with Greg Muth
Gene regulation in bacteria often occurs by protein
factors binding to DNA near the site of the start of transcription. It is also clear that regulation can occur by direct interactions
of small molecule co-factors (vitamins) with the mRNA after it has been transcribed. What has not been well established is a detailed biochemical
model of the RNA structures that form in the presence of co-factors and a
mechanism of discrimination used by these RNA structures to differentiate
between potentially very similar co-factors. The goal
of this project is to study the mRNA regulatory region and effector molecules
in the biosynthesis of the vitamin co-factor thiamin from bacteria Rhizobium
etli.
The project is a hybrid between molecular biology,
biochemistry and synthetic organic chemistry utilizing skills and techniques
from each of these disciplines.
Jeff Schwinefus, Summer 2003 Research
Why are proteins thermally stabilized in most cosolvent-water
mixtures while the DNA double helix is destabilized? As
an example, the cosolvent glycerol thermally stabilizes protein structure
while decreasing the melting temperature of double-stranded (ds) DNA. Since dsDNA and proteins are both polyelectrolytes with
hydrophobic cores, why is there such a difference in cosolvent influence
on dsDNA and protein structures? Interestingly, cosolvents
that stabilize protein structure are generally excluded from the protein surface. Are cosolvents then accumulated near the DNA surface,
disrupting hydration of the DNA helix? As of yet,
the answer is unknown. This is rather surprising considering
the elucidation of dsDNA physical chemistry in cosolvent-water mixtures has
potential meaning for cosolvent mediated protein-DNA interactions and the
polymer coil-globule transition.
My research during the summer of 2003 will attempt
to ascertain why the DNA double helix is destabilized in cosolvent-water
mixtures. Students involved in my research will measure
the accumulation or exclusion of cosolvent near the DNA surface using high
precision densimetry, a technique not normally encountered in the undergraduate
curriculum. Students will have the opportunity to
determine dsDNA water-cosolvent transfer free energies using densitometry
measurements as well as dsDNA melting free energies using uv-absorbance measurements. These free energies can be used to piece together the
thermodynamic cycle of dsDNA thermal destabilization. Students
involved in this research will gain exposure to biophysical chemistry concepts,
thermodynamics, and analytical techniques for the study of biopolymers.