Iron dioxygenases

Lipoxygenase (EC 1.13.11.12, nonheme iron dioxygenase), the substrate (polyunsaturated fatty acid) is poorly water soluble and the product (hydroperoxy-fatty acid) is hydrophilic. The reaction occurs in the aqueous phase [85,86]. 

In 1990, Triantaphylidds and coworkers reported on the preparative enzymatic synthesis of hnoleic acid (135) hydroperoxide 24a using soybean lipoxygenase-1. In this dioxygenation asymmetry is induced by the catalyst, the enzyme. The reaction was later used by Dussault and also by Baba and coworkers as key step in the preparation of more complex peroxides. The enzyme is a non-heme iron dioxygenase which catalyzes the incorporation of dioxygen into polyunsaturated fatty acids to yield E,Z conjugated diene hydroperoxides 24a-d. With this enzymatic method, the hydroperoxide 24a could... 

A large number of iron-containing proteins form nitrosyl complexes. Heme proteins, iron-sulfur proteins, and other iron proteins such as nonheme iron dioxygenases all form characteristic nitrosyl complexes. In enzymes in which the metal center has an open coordination position, NO often can be bound without severe disruption of the site. This introduces the possibility of reversibility of inhibition. 

Contents I. A. Cohen Metal-Metal Interactions in Metalloporphy-rins, Metalloproteins and Metalloenzymes. - L QueJr. Non-Heme Iron Dioxygenases. Structure and Mechanism. - H. Umezawa,... 

A detailed description of the electronic structure of the Fe(ll)NO model complexes and other nonheme iron dioxygenases has shown that the paramagnetic center giving... 

L. P. Wackett, Mechanism and applications of Rieske non-heme iron dioxygenases. Enzyme Microh. Tech. 31 (2002) 577. 

---