Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The transverse distribution of enzyme proteins and phospholipids within microsomal membranes was studied by analyzing membrane composition after treatment with proteases and phospholipases. Upon trypsin treatment of closed microsomal vesicles, NADH- and NADPH-cytochrome c reductases as well as cytochrome b5 were solubilized or inactivated, while cytochrome P-450 was partially inactivated. When microsomes were exposed to a concentration of deoxycholate which makes them permeable to macromolecules but does not disrupt the membrane, the detergent alone was sufficient to release four enzymes: nucleoside diphosphatase, esterase, beta-glucuronidase, and a portion of the DT-diaphorase. Introduction of trypsin into the vesicle lumen inactivated glucose-6-phosphatase completely and cytochrome P-450 partially. The rest of this cytochrome, ATPase, AMPase, UDP-glucuronyltransferase, and the remaining 50% of DT-diaphorase activity were not affected by proteolysis from either side of the membrane. Phospholipase A treatment of intact microsomes in the presence of albumin hydrolyzed all of the phosphatidylethanolamine, phosphatidylserine, and 55% of the phosphatidylcholine. From this observation, it was concluded that these lipids are localized in the outer half of the bilayer of the microsomal membrane; Phosphatidylinositol, 45% of the phosphatidylcholine, and sphingomyelin are tentatively assigned to the inner half of this bilayer. It appears that the various enzyme proteins and phospholipids of the microsomal membrane display an asymmetric distribution in the transverse plane.
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PMID:Enzyme and phospholipid asymmetry in liver microsomal membranes. 19 Feb 41

The interaction of glycoproteins of rough and smooth microsomal and Golgi membranes with Sepharose-bound lectins has been studied. One of these lectins was a crude preparation from wheat germ lipase which was found to bind primarily to N-acetyl neuraminic acid. Rough microsomes, smooth microsomes and Golgi membranes contain glycoproteins which bind to Concanavalin A (Con A specific for mannose residues) in decreasing amounts in the order indicated (rough, smooth and Golgi) and to wheat germ agglutinin (WGA, glucosamine-specific) and to the crude lipase preparation in increasing amounts in the order indicated. The small amount of binding of rough microsomes and Golgi membranes to Crotalaria (galactose-specific) increases substantially after neuraminidase treatment. Three submicrosomal particle preparations enriched either in AMPase or in NADH- or NADPH-oxidizing electron-transport enzymes contain glycoproteins which bind Con A and wheat germ agglutinin. The latter binding is sensitive to neuraminidase treatment. Two other submicrosomal particle preparations, both enriched in glucose-6-phosphatase activity, bind preferentially to WGA. This binding is, however, not sensitive to neuraminidase. Prolonged incubation with Ervilia lectin (mannose-specific) inhibits NADH-ferricyanide reductase activity, while the electron-transport chain involving cytochrome b5 is also inhibited by Crotalaria, indicating that both the flavoprotein and the cytochrome b5 are glycoproteins whose oligosaccharide chains have terminal mannose or galactose residues.
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PMID:Interaction of lectins with proteins of the endoplasmic reticulum and Golgi system of rat liver. 52 77

Male Wistar rats were given drinking water ad libitum with 0.075% thioacetamide (TAA) for 4 weeks. TAA treatment did not affect serum aminotransferase activities and total bilirubin content. The activities of 5'-nucleotidase, K+, Na+- and Mg2+-adenosine triphosphatases in liver plasma membrane preparations were strongly depressed, while that of gamma-glutamyl transferase was considerably increased. A decline in liver microsomal cytochrome P-450 and cytochrome b5 concentrations was also recorded. In contrast, the content of reduced glutathione in liver homogenate supernatant (9000 g) increased about 2-fold. As plasma membrane associated enzymes seem to be exclusively affected, the liver plasma membrane could be involved in the pathogenesis of the TAA-induced precirrhotic liver changes.
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PMID:Biochemical changes in the rat after chronic thioacetamide intoxication. 289 87

Male Wistar rats were treated for 3 weeks with alpha-naphthyl isothiocyanate (ANIT, 5.4 mmol per kg food). Chronic necrotic cholangitis without pronounced transaminasemia and hyperbilirubinemia developed. The activity of 5'-nucleotidase in liver plasma membrane preparations was strongly depressed (3.5 times) while the activities of K+-, Na+- and Mg++-ATPases were not affected. The liver microsomal cytochrome P-450 and cytochrome b5 contents decreased. Elevation of reduced glutathione liver content after challenge with ANIT was recorded. The observed biochemical changes may be important for the pathogenesis of ANIT-induced chronic cholangitis.
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PMID:Biochemical changes in alpha-naphthyl isothiocyanate-induced chronic cholangitis in the rat. 322 62

The chemoprotection extended by eugenol against carbon tetrachloride (CCl4) intoxication was established by studies on drug-metabolizing phase I and phase II enzymes. An overall decrease in drug-metabolizing enzymes, namely NADPH-cytochrome c reductase, NADH-cytochrome reductase, coumarin hydroxylase, 7-ethoxy coumarin-O-deethylase, UDP-glucuronyltransferase and glutathione-S-transferase, was observed with CCl4 intoxication, with a subsequent decrease in cytochrome P450 and cytochrome b5 content. CCl4 caused a significant decrease in microsomal phospholipids and the marker enzymes glucose-6-phosphatase and 5'-nucleotidase, and an increase in thiobarbituric acid reactive substances (TBARS). Simultaneous administration of eugenol with CCl4 inhibited the accumulation of TBARS and the decrease in the microsomal phospholipids and marker enzymes. Further, the chemical onslaught imposed by CCl4 on the drug-metabolizing system was removed successfully by eugenol. Eugenol appears to act as an in vivo antioxidant and as a better inducer of phase II enzymes than phase I enzymes. It is therefore suggested that eugenol could be an interesting basic structure for drug design.
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PMID:Effect of eugenol on drug-metabolizing enzymes of carbon tetrachloride-intoxicated rat liver. 778 11

The hepatoprotective activity of Picroliv, a standardized iridoid glycoside fraction of Picrorhiza kurroa, has been investigated by studying the protection of biochemical and histological changes induced in livers of rats given single oral doses (7 mg/kg) of aflatoxin B1. Administration of aflatoxin B1 resulted in a significant increase in 5'-nucleotidase, r-glutamyl transpeptidase, acid ribonuclease, total lipids, cholesterol and lipid peroxides in liver and transaminases, alkaline phosphatase and bilirubin in serum. However, the activity of glucose 6-phosphatase and levels of cytochrome P450, cytochrome b5, DNA, RNA, proteins and glycogen in liver and total proteins in serum decreased. The liver histology showed ballooned hepatocytes, degeneration, microvesicular fat, focal necrosis, bile duct hyperplasia and proliferation of oval and spindle cells in portal tracts. When Picroliv (25 mg/kg x 7 days) was given to aflatoxin B1 toxicated rats, the majority of the biochemical and histological changes were significantly protected. The findings indicate a hepatoprotective activity of Picroliv against aflatoxin B1 toxicity in rats.
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PMID:Picroliv protects against aflatoxin B1 acute hepatotoxicity in rats. 847 62