Glyceryl-ether monooxygenase [EC 1.14.16.5]. A microsomal enzyme of ether lipid metabolism

Taguchi, Hiroyasu; Armarego, W. L. F.

doi:10.1002/(sici)1098-1128(199801)18:1<43::aid-med3>3.0.co;2-s

Cited by 40 publications

(28 citation statements)

References 213 publications

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“…The supernatant was then dialyzed in 20 mM TrisCl (pH 7.4), 1 mM EDTA, and passed through a DEAE cellulose column at 3.5°C (DE52, Whatman), washed with buffer A [20 mM Tris-Cl (pH 7.4), 1 mM DTT] and then buffer A containing 40 mM NaCl. cPAH Scheme 1 1 The cPAH DNA sequence has been deposited in GenBank: accession number AF146711 started to elute at approximately 100 mM NaCl during a gradient with buffer A, varying NaCl from 40 to 300 mM. The eluted protein was concentrated under 30 PSI N 2 with an Amicon YM10 membrane at 3.5°C.…”

Section: Violaceum Pah Cloningmentioning

confidence: 99%

“…Among these oxygenases are the widespread iron-dependent glycerylether hydroxylases [1] and aromatic amino acid hydroxylases (AAAHs) [2]. In general, the product is released along with hydroxydihydropterin (carbinolamine) [3,4], which dehydrates spontaneously to the quinonoid dihydropterin [5,6].…”

Section: Introductionmentioning

confidence: 99%

“…In lieu of the difficulties presented by the complex multi-domain enzymes, we have focused our attention on PAH from the soil bacterium Chromobacterium violaceum (cPAH) 1 . The peptide sequence [15] and the crystallographic structure of this protein are highly analogous to the catalytic domain of the mammalian PAHs [16].…”

Section: Introductionmentioning

confidence: 99%

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Order of substrate binding in bacterial phenylalanine hydroxylase and its mechanistic implication for pterin-dependent oxygenases

2003

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Phenylalanine hydroxylase (PAH) is a pterin-dependent non-heme metalloenzyme that catalyzes the oxidation of phenylalanine to tyrosine, which is the rate-limiting step in the catabolism of Phe. Chromobacterium violaceum phenylalanine hydroxylase (cPAH) has been prepared and its steady-state mechanism has been investigated. The enzyme requires iron for maximal activity. Initial rate measurements, done in the presence of the 6,7-dimethyl-5,6,7,8-tetrahydropterin (DMPH(4)) cofactor, yielded an average apparent k(cat) of 36+/-1 s(-1). The apparent K(M) values measured for the substrates DMPH(4), L-Phe, and O(2) are 44+/-7, 59+/-10, and 76+/-7 microM, respectively. Steady-state kinetic analyses using double-reciprocal plots revealed line patterns consistent with a sequential ter-bi mechanism in which L-Phe is the middle substrate in the order of binding. The occurrence of a line intersection on the double-reciprocal plot abscissa when either pterin or O(2) is saturated suggests that, prior to O(2) binding, DMPH(4) and L-Phe are in associative pre-equilibrium with cPAH. Together with an inhibition study using the oxidized cofactor, 7,8-dimethyl-6,7-dihydropterin, it is conclusive that the mechanism is fully ordered, with DMPH(4) binding the active site first, L-Phe second, and O(2) last. This represents the first conclusive steady-state mechanism for a PAH enzyme.

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Section: Violaceum Pah Cloningmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Order of substrate binding in bacterial phenylalanine hydroxylase and its mechanistic implication for pterin-dependent oxygenases

2003

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“…Alkylglycerol mono-oxygenase (glycerylether mono-oxygenase, EC 1.14.16.5) is the only enzyme known to cleave the ether bond of alkylglycerols [1]. Alkylglycerols form an abundant and diverse class of lipids and phospholipids of humans and other animals and are thought to play a role in sperm and nerve development, in protection of the eye from cataract and in signal transduction of cytokines [2].…”

Section: Introductionmentioning

confidence: 99%

Catalytic residues and a predicted structure of tetrahydrobiopterin-dependent alkylglycerol mono-oxygenase

Watschinger

Fuchs

Yarov‐Yarovoy

et al. 2012

Biochemical Journal

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Alkylglycerol mono-oxygenase (EC 1.14.16.5) forms a third, distinct, class among tetrahydrobiopterin-dependent enzymes in addition to aromatic amino acid hydroxylases and nitric oxide synthases. Its protein sequence contains the fatty acid hydroxylase motif, a signature indicative of a di-iron centre, which contains eight conserved histidine residues. Membrane enzymes containing this motif, including alkylglycerol mono-oxygenase, are especially labile and so far have not been purified to homogeneity in active form. To obtain a first insight into structure–function relationships of this enzyme, we performed site-directed mutagenesis of 26 selected amino acid residues and expressed wild-type and mutant proteins containing a C-terminal Myc tag together with fatty aldehyde dehydrogenase in Chinese-hamster ovary cells. Among all of the acidic residues within the eight-histidine motif, only mutation of Glu137 to alanine led to an 18-fold increase in the Michaelis–Menten constant for tetrahydrobiopterin, suggesting a role in tetrahydrobiopterin interaction. A ninth additional histidine residue essential for activity was also identified. Nine membrane domains were predicted by four programs: ESKW, TMHMM, MEMSAT and Phobius. Prediction of a part of the structure using the Rosetta membrane ab initio method led to a plausible suggestion for a structure of the catalytic site of alkylglycerol mono-oxygenase.

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“…It is an essential cofactor for the hydroxylation of three aromatic amino hydroxylases that have important biochemical and physiological functions in the biosynthesis of dopamine, norepinephrine and serotonin (Thö ny et al, 2000). In addition, BH 4 serves as a cofactor for nitric oxide synthase (NOS; Marletta, 1993) and glyceryl-ether monooxygenase (Kaufman et al, 1990;Taguchi & Armarego, 1998).…”

Section: Introductionmentioning

confidence: 99%

Crystallization and preliminary characterization of dihydropteridine reductase fromDictyostelium discoideum

et al. 2008

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Dihydropteridine reductase from Dictyostelium discoideum (dicDHPR) can produce d-threo-BH 4 [6R-(1 0 R,2 0 R)-5,6,7,8-tetrahydrobiopterin], a stereoisomer of l-erythro-BH 4 , in the last step of tetrahydrobiopterin (BH 4 ) recycling. In this reaction, DHPR uses NADH as a cofactor to reduce quinonoid dihydrobiopterin back to BH 4 . To date, the enzyme has been purified to homogeneity from many sources. In this report, the dicDHPR-NAD complex has been crystallized using the hanging-drop vapour-diffusion method with PEG 3350 as a precipitant. Rectangular-shaped crystals were obtained. Crystals grew to maximum dimensions of 0.4 Â 0.6 Â 0.1 mm. The crystal belonged to space group P2 1 , with unit-cell parameters a = 49.81, b = 129.90, c = 78.76 Å , = 100.00 , and contained four molecules in the asymmetric unit, forming two closely interacting dicDHPR-NAD dimers. Diffraction data were collected to 2.16 Å resolution using synchrotron radiation. The crystal structure has been determined using the molecular-replacement method.

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Glyceryl-ether monooxygenase [EC 1.14.16.5]. A microsomal enzyme of ether lipid metabolism

Cited by 40 publications

References 213 publications

Order of substrate binding in bacterial phenylalanine hydroxylase and its mechanistic implication for pterin-dependent oxygenases

Order of substrate binding in bacterial phenylalanine hydroxylase and its mechanistic implication for pterin-dependent oxygenases

Catalytic residues and a predicted structure of tetrahydrobiopterin-dependent alkylglycerol mono-oxygenase

Crystallization and preliminary characterization of dihydropteridine reductase fromDictyostelium discoideum

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