Lowering oxidative stress with increased methionine content of mitochondrial aconitase

Oxidative stress occurs when reactive oxygen species (ROS), such as superoxide anion (O2' —), hydroxyl radical (HO.), and hydrogen peroxide (H2O2), build up to
detrimental levels in the cell, and effects of oxidative stress are associated with aging.
Mitochondria are the main site of oxidative stress, most likely due to the high level of
ROS produced during respiration. Mitochondrial aconitase is an enzyme involved in
respiration; due to the presence of an iron-sulfur cluster in the active site, it is a target for ROS. A plasmid containing the aconitase gene to be inserted into Saccharomyces
cerevisiae was designed, and will be used in the future for the pop-in pop-out method;
mitochondrial aconitase will be subjected to point mutations, replacing several leucine
and isoleucine amino acid residues with methionine residues near the active site and on
the surface of the enzyme. The amino acid methionine has a sulfur group, which also acts as a target for ROS and could prevent inactivation of the iron-sulfur cluster of aconitase.