LIPOXYGENASES - STRUCTURAL PRINCIPLES AND SPECTROSCOPY

Lipoxygenases catalyze the formation of fatty acid hydroperoxides, pro ducts used in further biochemical reactions leading to normal and path ological cell functions. X-ray structure analysis and spectroscopy hav e been applied to elucidate the mechanism of lipoxygenases. Two X-ray structures of soybean lipoxygenase-1 reveal the side chains of three h istidines and the COO- of the carboxy terminus as ligands to the catal ytically important iron atom. The enzyme contains a novel three-turn p i-helix near the iron center. Spectroscopic studies, including electro n magnetic resonance, X-ray absorption spectroscopy, infrared circular dichroism, and magnetic circular dichroism, have been applied to comp are lipoxygenases from varied sources and with different substrate pos itional specificity.