Bovine pancreatic trypsin inhibitor (BPTI) is a 58-residue small protein with three disulfide bridges. BPTI has been used extensively in protein folding studies, which suggest that the folding pathway proceeds via intermediates containing specific disulfide bonds. Formation of any one disulfide will stabilize the slow-exchange core and initiate folding by destabilizing the fully extended unfolded form. Our hypothesis, which we seek to test by total synthesis, is that any natural or unnatural cross- link that does not introduce unfavorable strain, will have the same effect. One type of cross-link is to circularize BPTI, which may be possible because in the solution structure of BPTI, the N- and C-termini are in close three-dimensional proximity.
The specific aims of this proposal are to synthesize and characterize circularly permuted variants of BPTI and analogues with unnatural cross-links. This work will provide definitive conclusions about the roles of disulfide bridges in BPTI folding and stability and is expected to lead to significant insights that contribute to our understanding of the critical factors governing proper folding of proteins.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32GM018341-02
Application #
2545976
Study Section
Special Emphasis Panel (ZRG3-BBCA (01))
Project Start
1996-09-30
Project End
Budget Start
1997-09-30
Budget End
1998-09-29
Support Year
2
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Chemistry
Type
Other Domestic Higher Education
DUNS #
168559177
City
Minneapolis
State
MN
Country
United States
Zip Code
55455