Abstract by Nathan Zuniga
Chemistry and Biochemistry
Glutathione and Homocystiene Interactions with Iron. Loading into Ferritin
The cellular Labile Iron Pool (LIP) is a reservoir of iron for cell use. In vitro studies show Fe(II) is the physiological oxidation state for delivery to enzymes. However, Fe (II) produces oxygen radicals (ROS). Hider proposed cells protect against ROS formation by complexing Fe(II) to Glutathione (GSH). We report that the GS:Fe(II) complex is not oxidized by O2 confirming Hider’s hypothesis. Oxidative stress diseases have elevated ROS production and elevated Homocysteine (Hcy) levels. We proposed that Hcy competes with GSH for Fe(II) and oxidizes Fe(II) to Fe(III) producing ROS. Iron loading into ferritin was monitored with Fe(II), GS:Fe(II) and Hcy:Fe(II). Kinetics demonstrate GS:Fe(II) loads Ferritin but Hcy:Fe(II) reacts with ferritin to produce a purple color (580 nM). Our results demonstrate the interactions biological molecules with Fe homeostasis.