Study of Metal binding in Cytochrome c oxidase by total reflection X-ray fluorescence (TXRF) spectrometry (CAT#: STEM-ST-0218-WXH)

Introduction

The enzyme cytochrome c oxidase or Complex IV, is a large transmembrane protein complex found in bacteria, archaea, and mitochondria of eukaryotes.<br />It is the last enzyme in the respiratory electron transport chain of cells located in the membrane. It receives an electron from each of four cytochrome c molecules and transfers them to one oxygen molecule and four protons, producing two molecules of water. In addition to binding the four protons from the inner aqueous phase, it transports another four protons across the membrane, increasing the transmembrane difference of proton electrochemical potential, which the ATP synthase then uses to synthesize ATP.<br />Cytochrome c oxidase contains a binding site for a non-redox-active metal at the interface of subunits I and II, usually a magnesium ion.