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CHEMISTRY SEMINAR
“Chaperoning Potential of Disulfide
Bond Forming Enzyme”
DR. CASSIDY DOBSON
DEPARTMENT OF CHEMISTRY & BIOCHEMISTRY
ST. CLOUD STATE UNIVERSITY
Friday, April 8
12:00 p.m.
WSB-122
Abstract:
Understanding protein folding is essential in biochemical research. Several diseases are a result of
incorrect protein folding and can ultimately lead to the formation of protein aggregates1. Chaperone
proteins can assist proper protein folding as a protein matures, but once protein aggregates form
generally they cannot be renatured to their individual, correct structure. Disulfide bond forming (DBF)
enzyme is a chaperone protein related to the class of Sso7d proteins from the hyperthermophilic
bacteria Sulfolobus solfataricus2. These proteins have demonstrated the unique ability to renature
proteins from pre-formed protein aggregates. In addition, DBF has been shown to specifically refold
proteins with incorrectly made disulfide bonds. Disulfide bonds in protein folding present a more
complicated arrangement because of their redox bond formation, which has been show to only be
rearranged in the presence of chaperones that themselves contain cysteines residues. DBF is unique
to the class of disulfide chaperones in that it does not contain cysteine amino acids, thus presenting a
new and different mechanism of disulfide bond rearrangement. We seek to understand the
mechanism of action DBF utilizes and apply this mechanism to a variety of different protein
aggregates.
1. Dobson, C. (2003) Protein folding and misfolding. Nature Reviews Mol Cell Bio 426, 884-890.
2. Guagliardi, A., Cerchia, L., Camardella, L., Rossi, M., Bartolucci, S. (1994) DBF (Disulfide bond
forming) enzyme from the hyperthermophilic archaebacterium Sulfolobus solfataricus behaves like a
molecular chaperone. Biocatalysis 11, 181-190.
This research provides students the opportunity for undergraduate students to pursue a variety of
biochemical endeavors including (but not limited to) molecular biology and cloning, protein
expression and purification, biophysical protein characterization and bioinformatics. The techniques
employed include a variety of protein purification strategies (IMAC, HIC, Ion-exchange, SEC), as well
as enzymatic assays, dynamic light scattering, HPLC, and mass-spectrometry amongst others.
Collaborations with other research groups bring the potential for 2D-NMR structural studies, X-ray
crystallographic studies, cell culture/physiological studies as well as drug-design and materials
science/polymer development.