+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on LinkedInFollow on LinkedIn

+ Translate

The nitric oxide complex of ferrous soybean lipoxygenase-1. Substrate, pH, and ethanol effects on the active-site iron

The nitric oxide complex of ferrous soybean lipoxygenase-1. Substrate, pH, and ethanol effects on the active-site iron

Journal of Biological Chemistry 262(25): 12137-12142

Soybean lipoxygenase is a non-heme iron enzyme that catalyzes the hydroperoxidation of linoleic acid by dioxygen. Exposure of ferrous lipoxygenase to nitric oxide yields a species displaying an electron paramagnetic resonance spectrum characteristic of a nearly axial S = 3/2 electronic spin system arising from the ferrous-nitrosyl complex. That spectrum is pH-sensitive, reflecting changes in the environment of the metal ion between pH 7 and 11. Addition of ethanol abolishes the effects of pH in a saturable fashion, resulting in a spectrum similar to that seen at pH 7. Exchange of lipoxygenase into H2(17)O leads to no significant line broadening in the low field portion of the spectrum, suggesting no coordination of water. The ferrous enzyme displays greater affinity for NO at pH 9 (where the enzyme is most active) than at pH 7. The binding of linoleic acid is competitive with that of NO at pH 9, but not at pH 7. These results are interpreted in terms of a model including only one iron site for exogenous ligands and an otherwise relatively stable iron coordination environment.

(PDF emailed within 1 workday: $29.90)

Accession: 041701846

Download citation: RISBibTeXText

PMID: 3040731

Related references

Near-IR CD/MCD Spectral Elucidation of Two Forms of the Non-Heme Active Site in Native Ferrous Soybean Lipoxygenase-1 Correlation to Crystal Structures and Reactivity. Journal of the American Chemical Society 116(25): 11610-11611, 1994

Tryptophan 500 and arginine 707 define product and substrate active site binding in soybean lipoxygenase-1. Biochemistry 43(41): 13063-13071, 2004

Electron attachment to iron iii nitric oxide center in nitric oxide peroxidase at low temperature rearrangement of the structure of the active site. Studia Biophysica 76(2): 77-83, 1979

Evidence for water coordinated to the active site iron in soybean lipoxygenase 1. Journal of the American Chemical Society 110(9): 2985-2986, 1988

Crystallographic determination of the active site iron and its ligands in soybean lipoxygenase L-1. Biochemistry. 32(25): 6320-6323, 1993

Substrate binding-induced changes in the EPR spectra of the ferrous nitric oxide complexes of neuronal nitric oxide synthase. Biochemistry 36(36): 10987-10992, 1997

X-ray absorption spectroscopy of soybean lipoxygenase-1. Influence of lipid hydroperoxide activation and lyophilization on the structure of the non-heme iron active site. European Journal of Biochemistry 207(2): 793-802, 1992

Computational Insights into Five- versus Six-Coordinate Iron Center in Ferrous Soybean Lipoxygenase. Journal of Physical Chemistry Letters 7(17): 3429-3433, 2016

The active site of aromatase cytochrome P-450. Differential effects of cyanide provide evidence for proximity of heme-iron and carbon-19 in the enzyme-substrate complex. Journal of Biological Chemistry 262(18): 8840-8844, 1987

Nitric oxide oxidises a ferrous mammalian lipoxygenase to a pre-activated ferric species. Febs Letters. 389(3): 229-232, 1996

Crystal structure of a lipoxygenase in complex with substrate: the arachidonic acid-binding site of 8R-lipoxygenase. Journal of Biological Chemistry 289(46): 31905-31913, 2015

Spectroscopic studies on ferrous non heme iron active sites variable temperature mcd probe of ground and excited state splittings in iron superoxide dismutase and lipoxygenase. Journal of the American Chemical Society 108(4): 835-836, 1986

X ray absorption spectroscopic studies of the high spin iron ii active site of isopenicillin n synthase evidence for iron sulfur interaction in the enzyme substrate complex. Biochemistry 31(19): 4596-4601, 1992

X-ray absorption spectroscopic studies of the high-spin iron(II) active site of isopenicillin N synthase: evidence for iron-sulfur interaction in the enzyme-substrate complex. Biochemistry 31(19): 4596-4601, 1992

Substrate, substrate analogue and inhibitor interactions with the ferrous active site of catechol 2,3-dioxygenase monitored through XAS studies. FEBS Letters 350(2-3): 207-212, 1994