Heme Degradation as Catalyzed by a Recombinant Bacterial Heme Oxygenase (Hmu O) from Corynebacterium diphtheriae
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منابع مشابه
Heme degradation as catalyzed by a recombinant bacterial heme oxygenase (Hmu O) from Corynebacterium diphtheriae.
Hmu O, a heme degradation enzyme in the pathogen Corynebacterium diphtheriae, catalyzes the oxygen-dependent conversion of hemin to biliverdin, carbon monoxide, and free iron. A bacterial expression system using a synthetic gene coding for the 215-amino acid, full-length Hmu O has been constructed. Expressed at very high levels in Escherichia coli BL21, the enzyme binds hemin stoichiometrically...
متن کاملIdentification of the proximal ligand His-20 in heme oxygenase (Hmu O) from Corynebacterium diphtheriae. Oxidative cleavage of the heme macrocycle does not require the proximal histidine.
The coordination and spin-state of the Corynebacterium diphtheriae heme oxygenase (Hmu O) and the proximal Hmu O H20A mutant have been characterized by UV-visible and resonance Raman (RR) spectrophotometry. At neutral pH the ferric heme-Hmu O complex is a mixture of six-coordinate high spin and six-coordinate low spin species. Changes in the UV-visible and high frequency RR spectra are observed...
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The heme oxygenase system was reconstituted from a heme oxygenase preparation highly purified from pig spleen microsomes and a partially purified NADPHcytochrome c reductase from pig liver microsomes. In the reconstituted heme oxygenase reaction, the relationship between the rate of heme degradation and the heme concentration was sigmoidal, and the heme concentration which gave the half-maximum...
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Heme oxygenase (HO), in conjunction with biliverdin reductase, degrades heme to carbon monoxide, ferrous iron and bilirubin (BR); the latter is a potent antioxidant. The induced isoform HO-1 has evoked intense research interest, especially because it manifests anti-inflammatory and anti-apoptotic effects relieving acute cell stress. The mechanisms by which HO mediates the described effects are ...
متن کاملCharacterization of the HEME Uptake Pathway Proteins from Streptococcus Pyogenes and Corynebacterium Diphtheriae
In Streptococcus pyogenes, the protein SiaA (HtsA) is part of a heme uptake pathway system and involved in heme transfer from Shp to the ABC transporter. SiaA mutants, in which alanine replaces the axial histidine (H229) and methionine (M79) ligands, as well as a lysine (K61) and cysteine (C58) located near the heme propionates, are reported. Studies on a mutant of a cysteine expected to be at ...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1999
ISSN: 0021-9258
DOI: 10.1074/jbc.274.30.21319