Enzymatic ring opening of an iron corrole by plant-type heme oxygenases: unexpected substrate and protein selectivities.
Heme oxygenases are widely distributed enzymes involved in the oxidative cleavage of the heme macrocycle that yields the open-chain tetrapyrrole biliverdin IX, CO, and iron. For the first time, two regioisomeric iron corroles [α-CH- and γ-CH-Fe(cor)] have been utilized as artificial substrate and cofactor analogues to mammalian, plant, cyanobacterial, and bacterial heme oxygenases. The non-natural enzymatic cleavage of γ-CH-Fe(cor), catalyzed by plant-type heme oxygenases from Arabidopsis thaliana and Synechocystis sp., happens selectively at the unexpected bipyrrolic position and yields a biomimetic biliverdin-like product. The reaction is selective for this corrole regioisomer and for plant-type heme oxygenases and is the first report of an enzymatic corrole ring opening.
Physiology of Microorganisms, Ruhr-University Bochum, 44780 Bochum, Germany.
Björn
B
Gisk
Frédérique
F
Brégier
Robin A
RA
Krüger
Martin
M
Bröring
Nicole
N
Frankenberg-Dinkel
D029681:Arabidopsis Proteins / Q000378:metabolism; D006418:Heme / Q000031:analogs & derivatives / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008665:Metalloporphyrins / Q000378:metabolism*; D010944:Plants / Q000201:enzymology; D013379:Substrate Specificity
D029681:Arabidopsis Proteins; D008665:Metalloporphyrins; C546809:iron corrole; D006418:Heme; C510568:HO3 protein, Arabidopsis; C510569:HO4 protein, Arabidopsis; D006419:Heme Oxygenase (Decyclizing)