Carbon monoxide and mitochondria
Carbon monoxide (CO) is capable of binding to some proteins containing other transition metals at their active sites, for instance, cobalt, nickel, and copper, thereby interfering with their functions. This chapter provides a summary of the biochemistry of CO as it pertains to heme proteins in mitochondria and their relationships to changes in mitochondrial and cellular function. In the cell, cytochrome coxidase, the terminal enzyme of the mitochondrial electron transport system, reduces molecular O2to water in a four-electron reaction. The proclivity of CO to enhance mitochondrial oxidant production has been shown for endogenous CO in intact hepatic blood vessels, resulting in increased susceptibility to further oxidant stress. At low CO concentrations, the initial CO-mediated redox changes in the electron transport chain are sensed as oxidant stress, generating a mitochondrial stress response that includes mitochondrial biogenesis and other elements of mitochondrial quality control.
