Effect of Coulombic interactions on transient partial unfolding in proteins
Abstract
Partial unfolding is a serious challenge for proteins. The consequences of partial unfolding include inactivation, degradation, or other deleterious events. The alteration of interaction energies between residues in proteins greatly affects not only the thermodynamic stability of a protein but also the energy required to reach these partially unfolded forms. Coulombic interactions have been shown to have significant influence on protein stability. In this thesis, we report the effect of Coulombic interactions on transient partial unfolding in RNase H*. First, the charge interactions were redesigned in order to modulate partial unfolding of RNase H*. By adjusting the Coulombic character of RNase H*, we were able to manipulate the energetics of partial unfolding. Next, we investigated the role of the Lys86–Asp108 salt bridge in RNase H*. Disruption of this salt bridge promoted partial unfolding of RNase H* significantly, while the complete removal of charges do not alter the global stability of the protein. Our results indicate that this salt bridge acts as a suppressor of partial unfolding in RNase H*.
Degree
M.S.
Advisors
Park, Purdue University.
Subject Area
Biochemistry|Biophysics
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