The Effect of Axial Ligands on the Redox Potential of Blue Copper Proteins
Blue copper proteins are crucial components in most electron transfer chains. These proteins coordinate a single copper atom which oscillates between Cu+1 and Cu+2 states upon receiving or donating a single electron. One method used to determine a protein?s role in electron transport chain is the evaluation of its redox potentials. The theory behind this research project is based from a trend that the redox potential of a blue copper protein correlates to the hydrophobicity of the amino acid residues coordinating at the axial ligand position. Therefore, we can predict a blue copper protein?s biophysical properties solely from its amino acid sequence. Blue copper proteins display a large range of redox potentials, which vary between +200mV and +600mV. Proteins with hydrophobic axial ligands such as Valine or Leucine have a high redox potential, around +580 mV. Contrarily, proteins with more hydrophilic axial ligands such as Glutamine, have redox potentials nearer to +200mV. If this trend does indeed correlate with the hydrophobicity of the axial ligand, then it can be used as a molecular marker to estimate the redox properties of blue copper proteins for which only amino acid sequence information is available.
Ray, Jeremiah, "The Effect of Axial Ligands on the Redox Potential of Blue Copper Proteins" (2005). URC Student Scholarship.
Aram M. Nersissian
Howard Hughes Medical Institute Undergraduate Science Education Grant