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 intestinal epithelium of Ascardia galli has been studied with various cytological and cytochemical techniques. It consists of large epithelial cells resting on a thick collagenous basal lamina. Their luminal surface is provided with microvilli. The intestinal cells store considerable amounts of glycogen and neutral lipids. Some intracellular granular inclusions, which stain for proteins, phospholipids and lipoproteins, are distributed throughout the cytoplasm. The brush border is composed of microvilli whereas the outer surface coat consists of saliva resistant PAS-positive material. The detailed histochemical analysis of surface material has revealed that it is composed of nonacetylated acid mucopolysaccharides rich in hyaluronic acid with carboxylate polyanions. The brush border shows intense activities of acid phosphatase and glucose-6-phosphatase, moderate of ATPase, and lipase, weak of 5'-nucleotidase. Acid phosphatase-positive intracellular structures are seen in the intestinal epithelium which form distinct aggregations.
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PMID:Morphological and histochemical observations on the intestinal epithelium of Ascardia galli (Nematoda: Ascaridida). 21 46

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

The reversibility of phosphoethanolamine transferase (EC 2.7.8.1) in rat brain is demonstrated in this paper. Microsomal ethanolamine glycerophospholipids were prelabeled with an intracerebral injection of [3H]ethanolamine 4 h before killing young rats. Labeled CDPethanolamine was produced by incubation of the microsomes with CMP, although to a lesser extent than for the previously observed release of CDPcholine. Ethanolamine and choline glycerophospholipids were labeled with [2-3H]glycerol by incubation with primary cultures of rat brain. Microsomes from rat brains, with diisopropyl phosphofluoridate for inhibition of lipases, were incubated with the labeled glycerophospholipids separately, and labeled diacylglycerols were produced. The kinetic parameters of phosphoethanolamine transferase and phosphocholine transferase (EC 2.7.8.2) were compared by incubating rat brain microsomes with [3H]CMP. Inclusion of AMP in the reaction mixture was necessary in order to inhibit the hydrolysis of CMP by an enzyme with the properties of 5'-nucleotidase (EC 3.1.3.5). For phosphoethanolamine transferase and phosphocholine transferase respectively, the Km values for CMP were 40 and 125 microM and the V values were 2.3 and 21.6 nmol/h per mg protein. The reversibility of both enzymes permits the interconversion of the diacylglycerol moieties of choline and ethanolamine glycerophospholipids. During brain ischemia, a principal pathway for degradation of ethanolamine glycerophospholipids may be by reversal of phosphoethanolamine transferase followed by hydrolysis of diacylglycerols by the lipase.
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PMID:A comparison of the reversibility of phosphoethanolamine transferase and phosphocholine transferase in rat brain microsomes. 301 Nov 1

Cholesteryl esterase activities were determined in homogenates of rat heart (ventricles), isolated, calcium-tolerant, cardiac myocytes and aortic tissue and were compared with acid and neutral triglyceride lipase activities in these fractions. Using cholesteryl oleate/phosphatidylcholine/taurocholate emulsions and digitonin pretreatment of the enzyme fractions, acid and neutral cholesteryl esterase activities were measured in all tissue preparations. In contrast to the acid and neutral triglyceridase and acid cholesteryl esterase activity, the neutral cholesteryl esterase activity was subject to substrate inhibition. Upon isolation of cardiac myocytes, and in contrast with the recovery of neutral triglyceride lipase activity, only a small portion of the neutral cholesteryl esterase (6%) was recovered, suggesting that nonmyocyte neutral cholesteryl esterase activity markedly contributes to the relatively high activity detectable in whole ventricular homogenates. The recovery of large amounts of neutral cholesteryl esterase activity in the supernatant of collagenase-digested heart tissue, obtained during the isolation of myocytes, which is also markedly enriched in activities of two endothelial marker enzymes (5'-nucleotidase and angiotensine-converting enzyme) may indicate the predominant contribution of neutral cholesteryl esterase activity from coronary endothelial cells to this activity detectable in ventricular homogenates. Relative to the activity in ventricular and myocyte homogenates, aorta homogenates possessed the highest specific neutral cholesteryl esterase activity. We propose that in addition to coronary endothelium, smooth muscle cells also contribute to the neutral cholesteryl esterase activity in ventricular homogenates.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cholesteryl esterase activities in ventricles, isolated heart cells and aorta of the rat. 303 10

Histochemical procedures for PMN granule enzymes were carried out on smears prepared from normal rabbit bone marrow, and the smears were examined by light microscopy. For each of the enzymes tested, azo dye and heavy metal techniques were utilized when possible. The distribution and intensity of each reaction were compared to the distribution of azurophil and specific granules in developing PMN. The distribution of peroxidase and six lysosomal enzymes (acid phosphatase, arylsulfatase, beta-galactosidase, beta-glucuronidase, esterase, and 5'-nucleotidase) corresponded to that of azurophil granules. Progranulocytes contained numerous reactive granules, and later stages contained only a few. The distribution of one enzyme, alkaline phosphatase, corresponded to that of specific granules. Reaction product first appeared in myelocytes, and later stages contained numerous reactive granules. The results of tests for lipase and thiolacetic acid esterase were negative at all developmental stages. Both types of granules stained for basic protein and arginine. It is concluded that azurophil and specific granules differ in their enzyme content. Moreover, a given enzyme appears to be restricted to one of the granules. The findings further indicate that azurophil granules are primary lysosomes, since they contain numerous lysosomal, hydrolytic enzymes, but the nature of specific granules is uncertain since, except for alkaline phosphatase, their contents remain unknown.
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PMID:Differences in enzyme content of azurophil and specific granules of polymorphonuclear leukocytes. I. Histochemical staining of bone marrow smears. 487 49

Twenty eight enzymatic activities and four macromolecular substances have been histochemically compared in rat and rabbit aortas, embedded in a common block. The study was carried out at different stages of development: 3 days, 3 months, 7-9 months and 17-19 months. In addition, lipase and cholinesterase were biochemically assayed in adult rat and rabbit aortas. The rat aortas (atheroresistant) had a better supply of aerobic oxidoreductases [linked to the pentose pathway (G6PD, 6PGD) as well as to the Krebs cycle (SD, ICD)], lipolytic enzymes (acid esterases, cholinesterase, lipase), lysosomal enzymes (acid PH/ase, Aryl-sulf/ase - Betaglu/ase), ADPase - ATPase - AlK Ph/ase Alpha GPD and acid lipids. Rabbit aortas (atherosensitive) were richer in metachromatic GAG, UDPGD (GAG Anabolism), glycogen, and related enzymes (phosphorylase, glycogen synthetase) as well as 5'-nucleotidase, Beta HBD, Lactate D and Aldolase. These differences support the hypothesis that arterial atherosensitivity is related to the activity and efficiency of smooth muscle cell energetic and catabolic processes, which govern the behaviour of lipids, proteins and carbohydrates as they penetrate the arterial wall. The factors that determine the proliferative and sclerogenic responses of arterial tissues to aggressions and, in particular, the response to lipids, remain, however, to be determined.
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PMID:A comparative study of the arterial tissue metabolism in atherosensitive and atheroresistant species. I. Comparison between rabbit and rat aortas. 734 89

A total of 25 apparently healthy adults (13 men and 12 women), 29.5 years (SD = 3.6 years) of age, served as subjects in a 24-h study conducted in Barcelona, Spain, in the spring of 1990. The group had a homogeneous pattern of meals, activity, and behavior. Six blood samples were collected at 4-h intervals over a single 24-h period beginning at 10:00 h. The oral temperature was measured at 2-h intervals to facilitate an independent biological time reference for the local population being studied. The serum concentration of 12 enzymes of clinical interest were measured in each sample: creatine kinase, creatine kinase 2, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, cholinesterase, lactate dehydrogenase, lactate dehydrogenase 1, 5'-nucleotidase, pancreatic alpha-amylase, and triacylglycerol lipase. We supposed that all experimental data obtained for a quantity came from a single "hypothetical subject" that represented the central tendency of the population and then these data were analyzed for circadian rhythm by single cosinor. A statistically significant circadian rhythm was detected in all quantities studied (p < or = 0.05) except for serum concentrations of pancreatic alpha-amylase and triacylglycerol lipase. The maximum daily rhythmic variation was approximately 10% (interval, 6-14%) for all quantities studied except pancreatic alpha-amylase (2.6%). This rhythmic variation is greater than the analytical variation except for 5'-nucleotidase and pancreatic alpha-amylase. The acrophases for the quantities studied (except that of triacylglycerol lipase) coincide with times near those of the oral temperature acrophase (18:01 local time). The results of this study will doubtless contribute to further documentation of the structure of the human circadian timing system and to establishment of time-qualified reference intervals for a defined group of subjects.
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PMID:Circadian rhythms of serum concentrations of 12 enzymes of clinical interest. 810 Apr 88