Purification and characterization of a carboxyl ester hydrolase from human pancreatic juice

Lagadic‐Gossmann, Dominique; Guy, Odette; Figarella, Catherine

doi:10.1016/0005-2744(78)90263-2

Cited by 146 publications

(89 citation statements)

References 18 publications

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“…A marked sensitivity t o serine inhibitors as well as -SH reagents has also been observed for two highly purified mammalian esterases capable of cleaving DEHP. These enzymes, the so-called non-specific lipase from rat pancreas [38 -401 and a broad-specificity carboxylesterase from human pancreatic juice [41], had apparent subunit molecular masses of 65 000 Da [38 -401 and I00000 Da [42] respectively. The specific D E H P esterase activity of the purified mammalian enzymes was about 50 mkat/kg protein and was thus 4000 times higher than the specific activity of the purified wheat enzyme which was, however, much more active with 4-nitrophenyl octanoate.…”

Section: Discussionmentioning

confidence: 99%

Plant biochemistry of xenobiotics. Purification and properties of a wheat esterase hydrolyzing the plasticizer chemical, bis(2-ethylhexyl)phthalate

Krell

Sandermann

1984

Eur J Biochem

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A soluble wheat esterase, catalyzing a cleavage of the mass-produced plasticizer chemical, bis(2-ethylhexy1)phthalate (DEHP), has been discovered. Although wheat plants and seeds as well as cultured wheat cells contained more than 12 non-specific esterase activities, only a single protein with a marked preference for a substrate chain-length of 6-8 carbon atoms was active with DEHP. This enzyme is shown to differ from all previously characterized plant lipases and esterases.The enzyme was purified 10-fold from wheat plants and 280-fold, to electrophoretic homogeneity, from cultured wheat cells. An apparent functional molecular mass of 38000Da and an apparent subunit molecular mass of 22000 D a were determined. Inhibitor experiments pointed to the catalytic involvement of a serine residue. Cleavage of DEHP by the purified enzyme was about lo4 times slower than cleavage of 4-nitrophenyl octanoate. This was consistent with previous evidence for a rate-limiting role of the esterase reaction in DEHP metabolism by intact wheat cellsThe fate of environmental chemicals in plants is of great practical concern in view of the huge global plant biomass and of the widespread use of pesticides in agriculture. It is clear that plants play an important role in the transformation of environmental chemicals [I, 21. However, the state of biochemical knowledge on the plant metabolism of xenobiotics is poor when compared to the detailed knowledge on the mammalian metabolism of xenobiotics [3]. Only few plant enzymes acting on xenobiotics have so far been purified and characterizedThe present report deals with a plant enzyme acting on the mass-produced plasticizer chemical, bis(2-ethy1hexyl)phthalate (DEHP, Fig.l). The 1979 production figure of DEHP was about 300 million pounds for the US alone [7]. DEHP is found world-wide as a contaminant of sediments and air. Phthalates, including DEHP, have also repeatedly been isolated from plant material (e.g. [8]), but many of these reports may have been due to contamination of the solvents used for extraction. The occurrence and toxicology of phthalate diesters have been thoroughly reviewed [7, 9, 101. The plant metabolism of phthalate diester plasticizers has only very recently been studied. A small amount (1.2%) of metabolites was present in the plant component (Elocku canademis) of a model ecosystem [l I]. Much higher amounts of DEHP conversion products were isolated from the plant components (Chara chara, Mentha aguatica) of another model ecosystem [12]. However, it remained unclear whether these products had been formed by the plant, by other components of the model ecosystems or through abiotic mechanisms. DEHP [4-61.Abbreviations. DEHP, bis(2-ethylhexy1)phthalate; MEHP, mono-(2-ethylhexy1)phthalate.

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Section: Discussionmentioning

confidence: 99%

Plant biochemistry of xenobiotics. Purification and properties of a wheat esterase hydrolyzing the plasticizer chemical, bis(2-ethylhexyl)phthalate

Krell

Sandermann

1984

Eur J Biochem

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“…Although the bile salt-stimulated cholesterol esterase was originally discovered in the pancreas and in the pancreatic juice (37)(38)(39), the cholesterol esterase was also found to be an abundant protein synthesized and secreted into the milk by lactating mammary glands of many species (39). Recently, this protein was found to be synthesized by the liver, including the HepG2 human hepatoma cell line (28,31,41).…”

Section: Expression Of Cholesteryl Ester Hydrolytic Enzymes In Mousementioning

confidence: 99%

Modified Low Density Lipoprotein Enhances the Secretion of Bile Salt-stimulated Cholesterol Esterase by Human Monocyte-Macrophages

Hui

1997

Journal of Biological Chemistry

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Reverse transcriptase-polymerase chain reaction was used to study the biosynthesis of two different cholesteryl ester hydrolases by human and mouse macrophages. Oligonucleotide primers for bile salt-stimulated cholesterol esterase yielded positive reactions with RNA isolated from human peripheral blood monocytes, monocyte-derived macrophages, the human monocytic THP-1 cells, and phorbol ester-induced THP-1 macrophages. In contrast, oligonucleotide primers for hormone-sensitive lipase yielded positive reactions only with RNA isolated from non-differentiated human THP-1 monocytic cells and peripheral blood monocytes, but not those obtained from differentiated THP-1 macrophages or monocyte-derived macrophages. Thus, while human monocytes were capable of synthesizing both enzymes, human macrophages synthesized only bile salt-stimulated cholesterol esterase and not the hormone-sensitive lipase. The synthesis of bile salt-stimulated cholesterol esterase by human macrophages was confirmed by detection of bile salt-stimulated cholesteryl ester hydrolytic activity in conditioned media of differentiated THP-1 cells and human peripheral blood monocyte-derived macrophages. Moreover, incubating human macrophages with oxidized low density lipoprotein (LDL) or acetylated LDL increased bile salt-stimulated cholesterol esterase activity in the conditioned media of these cells. These results with human macrophages were contrasted with results of studies with mouse macrophages, which showed the presence of hormone-sensitive lipase mRNA but not the bile salt-stimulated cholesterol esterase mRNA. Taken together, these results demonstrated species-specific differences in expression of cholesteryl ester hydrolytic enzymes in macrophages. The expression of bile salt-stimulated cholesterol esterase by human macrophages, in a process inducible by modified LDL, suggests a role of this protein in atherogenesis.A major characteristic of atherosclerosis is the accumulation of lipid-laden foam cells in the arterial wall. The foam cells are derived mainly from macrophages that have endocytosed modified lipoproteins through the scavenger receptor-mediated pathways (1). The cytoplasmic lipid droplets are mostly cholesteryl esters, which exist in a dynamic equilibrium with unesterified cholesterol and undergo continues hydrolysis and re-esterification (1). In the presence of exogenous cholesterol acceptors such as high density lipoproteins, the equilibrium favors cholesteryl ester hydrolysis with a net efflux of cholesterol from cells. In such circumstances, very little amount of cholesterol is stored in the macrophages. However, in the absence of extracellular cholesterol acceptors, or when acceptor concentration is low, equilibrium of the cholesteryl ester cycle favors esterification and cholesteryl esters accumulate in the cytosol.Cholesteryl ester can also accumulate in macrophages due to different levels of the esterification and de-esterification enzymes. Macrophages with high neutral cholesteryl ester hydrolytic activity were shown to accu...

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“…The CEL protein is one of three major lipases secreted from the exocrine pancreas into the pancreatic juice (1)(2)(3). In addition, a high level of CEL expression is found in lactating mammary glands where the enzyme is secreted as a component of breast milk (4).…”

mentioning

confidence: 99%

Endocytosis of Secreted Carboxyl Ester Lipase in a Syndrome of Diabetes and Pancreatic Exocrine Dysfunction

Torsvik

Johansson

Dalva

et al. 2014

Journal of Biological Chemistry

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Background: Mutations in the carboxyl ester lipase (CEL) gene cause a syndrome of pancreatic exocrine and endocrine dysfunction (MODY8). Results: Secreted mutant CEL forms aggregates that line the plasma membrane and are cleared by endocytosis. Conclusion:The mutant and normal CEL protein exhibit different cellular properties both in pancreatic and non-pancreatic cell models. Significance: MODY8 pathogenesis may involve endocytosis of a mutant CEL protein with toxic effect.

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Purification and characterization of a carboxyl ester hydrolase from human pancreatic juice

Cited by 146 publications

References 18 publications

Plant biochemistry of xenobiotics. Purification and properties of a wheat esterase hydrolyzing the plasticizer chemical, bis(2-ethylhexyl)phthalate

Plant biochemistry of xenobiotics. Purification and properties of a wheat esterase hydrolyzing the plasticizer chemical, bis(2-ethylhexyl)phthalate

Modified Low Density Lipoprotein Enhances the Secretion of Bile Salt-stimulated Cholesterol Esterase by Human Monocyte-Macrophages

Endocytosis of Secreted Carboxyl Ester Lipase in a Syndrome of Diabetes and Pancreatic Exocrine Dysfunction

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