Abstract by Kimberlee Stern
Chemistry and Biochemistry
Context Dependence of Non-covalent Interactions
Salt bridges are an important contributor to protein folding. We have shown previously that a long-range salt bridge interaction can be created by inserting an aromatic residue in between positively and negatively charged residues that are over 4 Å apart (the optimal distance for a salt-bridge). When molecular dynamic simulations were done on this interaction, it showed that the positively charged residue and the aromatic residue were in close proximity, but that the negatively charged residue was interacting in a salt-bridge with another residue. Using circular dichroism to collect thermodynamic data, we showed that this competing salt-bridge interaction helps the formation of the three-way interaction and that its absence results in an unfavorable interaction between the positive, negative and aromatic residues.