[13] Purification of PGH-PGE isomerase from sheep vesicular glands

Moonen, Peter; Buytenhek, M.; Nugteren, D.H.

doi:10.1016/0076-6879(82)86173-9

Cited by 36 publications

(12 citation statements)

References 5 publications

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“…Both of these precipitated proteins were found to possess glutathione-dependent PGE synthase activity but no glutathione Stransferase activity. The 17.5-kDa protein showed a K m for PGH 2 of 40 M, similar to what had been described by others investigating the microsomal PGE synthase (11). In contrast, the larger protein demonstrated a K m for PGH 2 of 150 M. Of interest, the IGG 1 (hei-7) antibody [but not the IGG 1 (hei-26) antibody], when incubated with intact sheep vesicular gland microsomes, caused coprecipitation of PGE synthase and cyclooxygenase activities, thereby demonstrating that the 17.5-kDa protein and the cyclooxygenase both are associated with the same membrane systems.…”

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confidence: 86%

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Identification of human prostaglandin E synthase: A microsomal, glutathione-dependent, inducible enzyme, constituting a potential novel drug target

Jakobsson

Thorén

Morgenstern

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

901

719

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Human prostaglandin (PG) E synthase (EC 5.3.99.3) is a member of a recently recognized protein superfamily consisting of membrane associated proteins involved in eicosanoid and glutathione metabolism (the MAPEG family). Previous designations of the protein are PIG12 and MGST1-L1. PGE synthase was expressed in Escherichia coli, and both cytosolic and membrane fractions were prepared. Western blot analysis specifically detected a 15-to 16-kDa protein in the membrane fraction. Both fractions were incubated with prostaglandin H 2 in the presence or absence of reduced glutathione. The membrane but not the cytosolic fraction was found to possess high glutathione-dependent PGE synthase activity (0.25 mol͞ min͞mg). The human tissue distribution was analyzed by Northern blot analysis. High expression of PGE synthase mRNA was detected in A549 and HeLa cancer cell lines. Intermediate level of expression was demonstrated in placenta, prostate, testis, mammary gland, and bladder whereas low mRNA expression was observed in several other tissues. A549 cells have been used as a model system to study cyclooxygenase-2 induction by IL-1␤. If A549 cells were grown in the presence of IL-1␤, a significant induction of the PGE synthase was observed by Western blot analysis. Also, Western blot analysis specifically detected a 16-kDa protein in sheep seminal vesicles. In summary, we have identified a human membrane bound PGE synthase. The enzyme activity is glutathione-dependent, and the protein expression is induced by the proinflammatory cytokine IL-1␤. PGE synthase is a potential novel target for drug development.Prostaglandin endoperoxide H 2 (PGH 2 ) is formed from arachidonic acid by the action of cyclooxygenases (cox) -1 or -2. cox-1 is constitutively expressed in many cells and tissues such as platelets, endothelium, stomach, and kidney whereas the cox-2 protein can be induced by proinflammatory cytokines like IL-1␤ at sites of inflammation (for recent reviews on cox see refs. 1-3). Downstream of the cyclooxygenases, the product PGH 2 can be further metabolized into the various physiologically important eicosanoids: e.g., PGF 2␣ , PGE 2 , PGD 2 , PGI 2 (prostacyclin), and thromboxane A 2 (4).The mechanism for the biosynthesis of PGE 1 and PGF 1␣ (formed by using dihomo-␥-linolenic acid instead of arachidonic acid) (5) by sheep vesicular glands was postulated to proceed via a cyclic endoperoxide (6) later designated PGH 2 (7-9). In short, the reactions catalyzed by cyclooxygenase start by stereospecific abstraction of a hydrogen atom from carbon 13 of arachidonic acid. The resulting carbon radical reacts with molecular oxygen followed by the formation of the 9,11-endoperoxide and the bond between C-8 and C-12. Thereafter, a second molecule of oxygen is incorporated at C-15 followed by reduction to a hydroperoxy group, and PGG 2 is formed. This hydroperoxy group can subsequently be reduced by the peroxidase activity of the cyclooxygenase (in the presence of a reducing agent: e.g., glutathione) thus forming PGH 2 . The enzy...

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confidence: 86%

“…The enzyme(s) responsible for the isomerization of PGH 2 into PGE 2 are not well known. Attempts have been made to isolate the microsomal PGE synthase from ovine and bovine seminal vesicles, an organ known to contain high levels of activity (10,11). These studies have shown that the microsomal PGE synthase can be solubilized and partly purified.…”

mentioning

confidence: 99%

Identification of human prostaglandin E synthase: A microsomal, glutathione-dependent, inducible enzyme, constituting a potential novel drug target

Jakobsson

Thorén

Morgenstern

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

901

719

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“…Many attempts have been made to purify the protein(s) involved in PGE 2 production (Ogino et al, 1977;Moonen et al, 1982). The results indicated that several different PGE 2 synthases exist (Tanaka et al, 1987;Watanabe et al, 1997).…”

Section: A Identificationmentioning

confidence: 99%

Membrane Prostaglandin E Synthase-1: A Novel Therapeutic Target

2007

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“…Over the last 30 years, several groups have purified this enzyme. [16][17][18][19] At least three different types of mammalian PGESs have been isolated. Ogorochi et al and Meyer et al independently purified the enzyme from the cytosol of human brain 18 and Ascaridia galli, 19 respectively.…”

Section: Introductionmentioning

confidence: 99%

“…20 The membrane-associated PGES (mPGES-1) was partially purified from microsomal fractions of bovine and sheep vesicular glands, and was shown to require GSH. 16,17,21 Jakobsson et al expressed human GSHspecific, mPGES-1 in E. coli. 22 cPGES and mPGES-1 in many organs are GSH-dependent enzymes.…”

Section: Introductionmentioning

confidence: 99%