Ligand Binding and Structural Dynamics in C-Type Cytochromes

Abstract

164 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009.The first molecular dynamic simulations of the interaction of cyt c and yeast bc1 complex are described. Contrary to results from crystallographic studies, the simulations reveal multiple dynamic hydrogen bonds and salt bridges in the cyt c-c 1 interface. A novel structural change in cyt c is also reported, involving residues 25--30, which may be responsible for cyt c destabilization. An interaction between cyt c1 monomers is proposed to be responsible for limiting the binding of cyt c to only one molecule per bc 1 dimer by altering the affinity of the cytochrome c binding site on the second cyt c1 monomer. A mechanism is also proposed explaining changes in cyt c binding affinity related to the position of the headgroup of the iron-sulfur protein.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD