Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two-hour heat exposure (40-41 degrees C) was shown to change the circadian rhythms of enteral gamma-amylase, maltase and sucrase activities. The character and obviousness of the changes depended on the type of enzyme activity and the portion of the small intestine. The heat exposure did not change daily mean levels of enzymatic activities and their distribution along the small intestine.
Fiziol Zh SSSR Im I M Sechenova 1992 Sep
PMID:[The effect of heat exposure on the circadian rhythm of the enzymatic activity in different sections of the rat small intestine]. 133 33

A yeast lytic enzyme was covalently immobilized on an enteric coating polymer, Eudragit S, that is reversibly soluble and insoluble (S-IS) depending on the pH of the reaction medium. The yeast lytic enzyme immobilized on Eudragit S (Y-E) showed a sharp response of solubility to slight changes in pH without decrease in enzymatic activity. The specific activity per amount of enzyme protein of Y-E for dry yeast cells was about two-thirds that of the native enzyme. In both lysis reactions of dry and pressed baker's yeast cells, changing the pH of the reaction medium from 7.0 to 4.8 at an appropriate interval allows the insoluble Y-E and the reaction products (soluble protein for dry yeast cells and invertase and soluble protein for pressed baker's yeast cells) to be repeatedly separated. The reaction method using a reversible S-IS enzyme is a promising procedure for repeated use of the enzyme in a heterogeneous reaction system containing yeast cells as a substrate.
Appl Microbiol Biotechnol 1990 Sep
PMID:Properties and repeated use of a reversibly soluble-insoluble yeast lytic enzyme. 136 43

Results presented in a previous report from this laboratory indicated the presence, in crude extracts from sycamore (Acer pseudoplatanus) and spinach (Spinacea oleracea), of a sucrose synthase (EC 2.4.1.13) showing high affinity for ADP as the glucose acceptor in the sucrose-cleaving reaction. In the present paper we report that the modified enzymatic method previously used to measure sucrose synthase activities leads to the detection of artifactual ADP-dependent sucrose synthase, which in fact arises from the combined action of invertase (EC 3.2.1.26) and nucleoside diphosphate kinase (EC 2.7.4.6) activities. We also present data on the partial purification of nucleoside diphosphate kinase from sycamore cells.
FEBS Lett 1992 Sep 14
PMID:Artifactual detection of ADP-dependent sucrose synthase in crude plant extracts. 138 19

Lactase-phlorizin hydrolase was isolated by immunoadsorption chromatography from rabbit brush-border membrane vesicles. Inactivation of the enzyme with [3H]conduritol-B-epoxide, a covalent active site-directed inhibitor, labeled glutamates at positions 1271 and 1747. Glu1271 was assigned to lactase, Glu1747 to phlorizin hydrolase activity. In contrast, the nucleophiles in the active sites of sucrase-isomaltase are aspartates (Asp505 and Asp1394). Asp505 is a part of the isomaltase active site and is localized on the larger subunit, which carries the membrane anchor also, while Asp1394 is a part of the active of sucrase. Alignment of these 2 nucleophilic Glu residues in lactase-phlorizin hydrolase and of their flanking regions with published sequences of several other beta-glycosidases allows the classification of the configuration retaining glycosidases into two major families: the "Asp" and the "Glu" glycosidases, depending on the carboxylate presumed to interact with the putative oxocarbonium ion in the transition state. We offer some predictions as to the Glu acting as the nucleophile in the active site of some glycosidases. By hydrophobic photolabeling, the membrane-spanning domain of lactase-phlorizin hydrolase was directly localized in the carboxyl-terminal region thus confirming this enzyme as a monotopic type I protein (i.e. with Nout-Cin orientation) of the brush-border membranes. A simplified version of the Me2+ precipitation method to efficiently and simply prepare brush-border membrane vesicles is also reported.
J Biol Chem 1992 Sep 15
PMID:Location of the two catalytic sites in intestinal lactase-phlorizin hydrolase. Comparison with sucrase-isomaltase and with other glycosidases, the membrane anchor of lactase-phlorizin hydrolase. 138 57

The synergistic effects of dexamethasone (DEX) and thyroxine (T4) on the postnatal maturation of the 13-d-old rodent small intestine has been studied. Previous studies have shown that hydrocortisone and T4 produced a synergistic response in enzyme maturation. However, T4 elevates corticosteroid-binding globulin, which reduces the clearance of hydrocortisone. Thus, the apparent synergy between T4 and hydrocortisone may have been due to increased glucocorticoid availability. DEX, which does not bind to corticosteroid-binding globulin, was given (d8-12) at 25 pmol (i.e. 0.01 micrograms)/g body wt/d as established by a dose-response study in which this dose of DEX induced one third the maximum response in sucrase activity. In this way, synergy with T4 (130 pmol/g body wt/d, i.e. 0.1 micrograms/g body wt/d, d 5-12) could still be observed. Glucoamylase, lactase, acid beta-galactosidase, alkaline phosphatase, and sucrase activities were determined in two regions of the small intestine. Overall, the results for the two hormones administered alone showed intestinal maturation to be not significantly affected in the T4 group and partially stimulated in the DEX group. When combined, DEX + T4 synergistically increased jejunal sucrase, ileal glucoamylase, and duodenal alkaline phosphatase, and lowered ileal acid beta-galactosidase. The striking exceptions to the general pattern were two brush border enzymes that normally decline during intestinal maturation, namely ileal alkaline phosphatase and jejunal and ileal lactase. For these enzymes, DEX alone did not elicit precocious maturation, and there was no evidence for a synergistic interaction of these two hormones. Serum corticosterone concentrations also were measured. When corticosterone concentrations were compared with enzyme activity, no correlation was found.(ABSTRACT TRUNCATED AT 250 WORDS)
Pediatr Res 1992 Sep
PMID:Synergistic effects of thyroxine and dexamethasone on enzyme ontogeny in rat small intestine. 140 67

An investigation was conducted on the influence of the presence of zinc in an elemental diet on the mucosa of residual intestine after massive small bowel resection. A total of 34 male Sprague-Dawley rats were divided into five groups: control animals (n = 10) were killed after overnight fasting; a second group (n = 14) underwent massive small bowel resection preserving 10 cm of terminal ileum, and the third group (n = 10) underwent sham operation. Animals in the second and third groups were fed either a commercially available elemental diet or a zinc-deficient diet for 2 weeks; they were then killed. In animals receiving the zinc-deficient diet, a significant decrease (P < 0.05) was noted in plasma zinc and total protein, and in mucosal wet weight (duodenum), thickness (duodenum and ileum), and protein (duodenum) and DNA (duodenum) content. Mucosal sucrase and maltase specific activities in the duodenum and ileum fell but diamine oxidase levels did not. These results suggest that zinc plays an important role in intestinal adaptation in the rat, and indicate that this trace element is essential for intestinal mucosal preservation in this animal.
Br J Surg 1992 Sep
PMID:Zinc-deficient diet impairs adaptive changes in the remaining intestine after massive small bowel resection in the rat. 142 69

Phytomonas sp. isolated from Euphorbia characias was adapted to SDM-79 medium. Cells isolated in the early stationary phase of growth were analyzed for their capacity to utilize plant carbohydrates for their energy requirements. The cellulose-degrading enzymes amylase, amylomaltase, invertase, carboxymethylcellulase, and the pectin-degrading enzymes polygalacturonase and oligo-D-galactosiduronate lyase were present in Phytomonas sp. and were all, except for amylomaltase, excreted into the external medium. Glucose, fructose and mannose served as the major energy substrates. Catabolism of carbohydrates occurred mainly via aerobic glycolysis according to the Embden-Meyerhof pathway, of which all the enzymes were detected. Likewise, the end-products of glycolysis, acetate and pyruvate, glycerol, succinate and ethanol were detected in the culture medium, as were the enzymes responsible for their production. Mitochondria were incapable of oxidizing succinate, 2-oxoglutarate, pyruvate, malate and proline, but had a high capacity to oxidize glycerol 3-phosphate. This oxidation was completely inhibited by salicylhydroxamic acid. No cytochromes could be detected either in intact mitochondria or in sub-mitochondrial particles. Mitochondrial respiration was not inhibited by antimycin, azide or cyanide. The glycolytic enzymes, from hexokinase to phosphoglycerate kinase, and the enzymes glycerol kinase, glycerol-3-phosphate dehydrogenase, phosphoenolpyruvate carboxykinase, malate dehydrogenase and adenylate kinase, were all associated with glycosomes that had a buoyant density of about 1.24 g cm-1 in sucrose. Cytochemical staining revealed the presence of catalase in these organelles. The cytosolic enzyme pyruvate kinase was activated by fructose 2,6-bisphosphate, typical of all other pyruvate kinases from Kinetoplastida. The energy metabolism of the plant parasite Phytomonas sp. isolated from E. characias resembled that of the bloodstream form of the mammalian parasite Trypanosoma brucei.
Mol Biochem Parasitol 1992 Sep
PMID:Characterization of carbohydrate metabolism and demonstration of glycosomes in a Phytomonas sp. isolated from Euphorbia characias. 143 59

1. Intestinal disaccharidases were studied in nectarivorous (Leptonycteris curasoae and Glossophaga soricina), frugivorous (Artibeus jamaicensis and Sturnira lilium), and insectivorous (Pteronotus personatus) adult bats. 2. Adult bats lacked measurable lactase activity. With the exception of trehalase activity, which was present only in P. personatus, nectar- and fruit-eating bats exhibited higher disaccharidase activities standardized by intestinal nominal area than insect-eating P. personatus. 3. Maltase and sucrase activities were significantly linearly correlated. 4. Apparent affinity of sucrase varied almost 5-fold among species. This variation may reflect unstirred layer effects resulting from sucrase being a membrane bound enzyme rather than differences in the "true" affinity of sucrase in solution. 5. Passerine birds showed higher maltase activity per unit of sucrase activity than bats and hummingbirds. Maximal sucrase and maltase activities standardized per intestinal nominal area are 1.5-2 times higher in hummingbirds than in nectar-feeding bats.
Comp Biochem Physiol B 1992 Sep
PMID:Intestinal disaccharidases in five species of phyllostomoid bats. 145 28

We have constructed a set of replicating and integrating vectors that allow expression and secretion of Clostridium thermocellum endoglucanase A in Saccharomyces cerevisiae using the alpha-factor or the invertase promoters and secretion signals. The enzyme expressed in yeast was enzymatically active regardless of its degree of glycosylation and was released into the culture medium. One advantage of using this experimental system is that secretion of the reporter enzyme can be detected in individual colonies facilitating the isolation of mutants. A second advantage is that transit through the secretory pathway, as judged from the extent of glycosylation, can be easily monitored by staining for enzyme activity in agar replicas of polyacrylamide gels.
Anal Biochem 1991 Sep 02
PMID:Endoglucanase A gene fusion vectors for monitoring protein secretion and glycosylation in yeast. 178 81

Cell wall inulinase (EC 3.2.1.7) was purified from Kluyveromyces marxianus var. marxianus (formerly K. fragilis) and its N-terminal 33-amino acid sequence was established. PCR amplification of cDNA with 2 sets of degenerate primers yielded a genomic probe which was then used to screen a genomic library established in the YEp351 yeast shuttle vector. One of the selected recombinant plasmids allowed an invertase-negative Saccharomyces cerevisiae mutant to grow on inulin. It was shown to contain an inulinase gene (INU 1) encoding a 555-amino acid precursor protein with a typical N-terminal signal peptide. The sequence of inulinase displays a high similarity (67%) to S. cerevisiae invertase, suggesting a common evolutionary origin for yeast beta-fructosidases with different substrate preferences.
FEBS Lett 1991 Sep 02
PMID:Cloning and sequencing of the inulinase gene of Kluyveromyces marxianus var. marxianus ATCC 12424. 184 May 29


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