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)

The production of dextransucrase from Leuconostoc mesenteroides NRRL B-512F was stimulated 2-fold by the addition of 0.005% of calcium chloride to the medium; levansucrase levels were unaffected. Dextransucrase was purified by concentration and dialysis of the culture supernatant with a Bio-Fiber 80 miniplant, and by treatment with dextranase followed by chromatography on Bio-Gel A-Fm. A 240-fold purification, with a specific activity of 53 U/mg, was obtained. Contaminating enzyme activities of levansucrase, invertase, dextranase, glucosidase, and sucrose phosphorylase were decreased to non-detectable levels. Poly(acrylamide)-gel electrophoresis of the purified enzyme showed only two protein bands, both of which had dextransucrase activity. These bands also gave a carbohydrate stain, indicating that the dextransucrase could be a glycoprotein. Acid hydrolysis, followed by paper chromatography, of the purified enzyme showed that the major carbohydrate was mannose. Concanavalin A completely removed dextransucrase activity from solution, confirming the mannoglycoprotein character of the enzyme. Dextransucrase activity was not altered by the addition of 0.008-4 mg/ml of dextran, but its storage stability was increased by the addition of 4 mg/ml of dextran. As previously shown by others, the activity of dextransucrase was decreased by EDTA, and was restored by the addition of calcium ions. Zinc, cadmium, lead, mercury, and copper ions were inhibitory to various degrees.
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PMID:Production, purification, and properties of dextransucrase from Leuconostoc mesenteroides NRRL B-512F. 10 66

It has been shown that soil pollution with heavy metals (copper, nickel) lead to negative changes in parameters characterizing potential biological activity of soil (nitrogen-fixation, breath, invertase activity, bacteria and fungi count). More profound changes were observed in sandy soil compared to loamy soil. A direct relationship of these effects with the content of mobile forms of heavy metals in soil has been established. For the comparative and prognostic investigation of the danger of soil pollution with heavy metals it has been suggested to use a coefficient of differences in the content of mobile forms and a coefficient of biological effect.
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PMID:[Changes in biological activity of turf-podzolic soil of different mechanical composition contaminated with heavy metals]. 222

Disaccharidases of oral bacteria, especially alpha-glucosidase and beta-fructofuranosidase, are considered to play an important role in the induction of dental caries. Upon the examination of disaccharidases from several strains of saccharolytic oral bacteria, we found all of those bacteria to be capable of hydrolyzing the glycosidic linkage of sucrose. One species of bacteria, Rothia dentocariosa, was found to contain a single disaccharidase, alpha-glucosidase. This enzyme was partially purified by ammonium sulfate precipitation, gel filtration and ion-exchange column chromatography. The optimum pH and temperature for the enzyme activity was found to be 6.8-7.0 and 40 degrees C, respectively. The enzyme activity was strongly inhibited by Ag+, Hg2+, Cu2+, Fe2+ and Tris (Hydroxymethyl) aminomethane.
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PMID:Partial purification and characterization of alpha-glucosidase from Rothia dentocariosa. 263 58

Activities of the enzymes lactase, sucrase, maltase, alkaline phosphatase, and superoxide dismutase (SOD) were measured in mucosa of duodenum and ileum of the rat after 70% resection of mid-small intestine or sham operation (transection). We also measured the concentrations of zinc, copper, and manganese in several tissues to assess trace metal homeostasis postresection. Resection resulted in decreased specific activities of disaccharidases and alkaline phosphatase in duodenum, while specific activities remained unchanged in ileum. Specific activity of total SOD (the sum of Cu-Zn and Mn SOD) and Mn SOD was the same in duodenum after resection but was markedly increased in ileum. Tissue trace metal concentrations changed minimally. Because of postresection mucosal growth, total segmental activity of disaccharidases and alkaline phosphatase was the same in duodenum and increased in ileum of resected compared to transected rats. Segmental activity of total SOD and Mn SOD doubled in duodenum and trebled in ileum of resected as compared to transected rats. Thus, total segmental enzyme activity is maintained or increased postresection by increased enterocyte proliferation rate and mucosal growth.
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PMID:Adaptation of the duodenum and ileum of the rat to mid-gut resection: enzyme activity and trace metal status. 308 Aug 64

Intestinal adaptation has been studied in rats with pancreatic atrophy induced by feeding a copper-deficient diet and penicillamine and in rats with carbohydrate maldigestion induced by feeding of an alpha-glucosidase inhibitor (acarbose). Pancreatic atrophy led to a significant increase of weight, protein, and DNA content as well as specific activities and total amounts of the enzymes sucrase and maltase in the distal but not in the proximal part of the small intestine. Plasma levels of CCK and GIP were significantly higher in rats with pancreatic atrophy, whereas plasma levels of gastrin and insulin were lower. Tissue concentrations of gastrin in the antrum and GIP in duodenum and jejunum were unchanged. Duodenal CCK and jejunal substance P, somatostatin, and VIP and ileal substance P and somatostatin were significantly decreased in rats with acinar atrophy. Glucosidase inhibition by acarbose feeding led to weight increase of the small intestine and cecum. This was more marked when acarbose was fed together with a fiber-free diet. Under these conditions the protein and DNA content also increased significantly in both gut segments and maltase and sucrase content predominantly in the distal part. Insulin plasma concentration decreased significantly in the acarbose-fed groups, whereas GIP, gastrin, and CCK plasma concentrations remained unchanged. After fiber-rich diet tissue concentrations of gastrin in the antrum and insulin in the pancreas were significantly higher and GIP concentrations in the duodenum and jejunum significantly lower than after fiber-free diet. Acarbose increased the pancreatic insulin concentration only in the fiber-free group and did not influence gastrin and GIP concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Adaptation of the small intestine to induced maldigestion in rats. Experimental pancreatic atrophy and acarbose feeding. 389 54

The beta-fructofuranosidase from Kluyveromyces fragilis was purified to one band on electrophoresis by 3 different methods. Two of the preparations were found to be impure by isoelectric focusing. This demonstrates the need for more than one criteria of homogeneity when purifying this enzyme. The enzyme was found to be a glycoprotein, stable at 50 degrees C, with a pH optimum of 4.5. The cations Hg2+, Ag+, Cu2+ and Cd2+ exhibited a marked inhibition of the enzyme. Competitive inhibition was observed with the fructose analog 2,5-anhydro-D-mannitol suggesting that the enzyme is inhibited by the furanose form of fructose.
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PMID:Purification and properties of the beta-fructofuranosidase from Kluyveromyces fragilis. 688 6

Riboflavin is known to generate superoxide anion upon photoillumination and in the presence of Cu(II) causes fragmentation of DNA. In the present study we examined the effect of riboflavin and Cu(II) on bovine serum albumin, invertase and lysozyme. Using fluorescence quenching experiments, it is shown that riboflavin binds to protein and causes fragmentation which in the presence of Cu(II) is enhanced. Using neocuproine as the Cu(I) sequestering reagent, it has also been shown that Cu(I) is an essential intermediate in the protein fragmentation reaction. Results obtained with various scavengers of active oxygen species strongly suggest that the species predominantly responsible for protein breakage is hydroxyl radical.
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PMID:Enhanced protein degradation by photoilluminated riboflavin in the presence of Cu(II). 770 5

An efficient expression/purification procedure has been developed which allows the production of pure, biologically active recombinant leech-derived tryptase inhibitor (rLDTI), originally found in the leech Hirudo medicinalis. The gene for LDTI was generated synthetically from three overlapping oligonucleotides by PCR synthesis. LDTI was expressed in the yeast Saccharomyces cerevisiae under the control of the copper-inducible CUP1 promoter and fused to the invertase signal sequence (SUC2). The entire expression cassette was inserted into the yeast high-copy vector pDP34. Appropriate host strains transformed with the expression plasmid secreted rLDTI into the medium upon copper addition. Proteinchemical analysis of the secreted rLDTI revealed exclusively inhibitor with the correct N-terminal sequence. Up to 60% of the rLDTI, however, appeared to be modified by glycosylation and the unglycosylated material showed heterogeneity at the C-terminus. Besides full-length rLDTI, truncated rLDTI species lacking either the terminal Asn46 or in addition the penultimate Leu45 were isolated. The C-terminally truncated variants were eliminated using a S. cerevisiae host strain disrupted in the structural genes of carboxypeptidases yscY and ysca, thus identifying these proteases as being responsible for the degradation of rLDTI. Mature rLDTI was purified in high yields from the culture supernatant of the carboxypeptidase-deficient yeast strain by cation-exchange chromatography and reverse-phase HPLC. The recombinant protein is at least 98% pure, based on HPLC and capillary electrophoresis, and is fully biologically active. Structural identity with the authentic leech protein was confirmed by sequence analysis and molecular-mass determination. The purified protein was tested for its ability to inhibit tryptase and trypsin in vitro and to interfere with the tryptase-induced proliferation of human fibroblasts and keratinocytes. Recombinant LDTI appears to be as potent as the authentic leech protein, exhibiting Ki-values of approximately 1.5 nM and approximately 1.6 nM against human tryptase and bovine trypsin, respectively. The tryptase-induced proliferation of human fibroblasts and keratinocytes was inhibited with half-maximum values of approximately 0.1 nM and approximately 1 nM, respectively. The availability of the recombinant material will allow evaluation of the concept of tryptase inhibition in various disease models and to test the therapeutic potential of LDTI in mast-cell-related disorders.
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PMID:Purification, characterization and biological evaluation of recombinant leech-derived tryptase inhibitor (rLDTI) expressed at high level in the yeast Saccharomyces cerevisiae. 891 64

beta-Fructofuranosidase [EC 3.2.1.26] in Clostridium perfringens was induced in the presence of sucrose and suppressed in the presence of glucose or maltose. The enzyme seems to be present in protoplasm in a soluble state. The beta-fructofuranosidase from C. perfringens cells grown on sucrose was purified by ammonium sulfate precipitation. DEAE-cellulose chromatography, Sephadex G-150 gel filtration, and hydroxylapatite chromatography to a homogeneous state. The molecular weight was 37,000 by gel filtration using Sephadex G-150 and by SDS-polyacrylamide gel electrophoresis. The amino acid composition is not much different from those of other microorganisms, but the Glx content was a little higher. The enzyme was inhibited by heavy metals, such as Hg2+, Cu2+, and Ag+, as well as pCMB; the activity was restored by incubating with mercaptoethanol. Fructose and amines including Tris and aniline had inhibitory effects.
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PMID:Purification and properties of beta-fructofuranosidase from Clostridium perfringens. 914 17

The main component of inulinase was purified from fermentation broth of Aspergillus niger 319 to homogeneity by using ammonium sulfate fraction, ion-exchange chromatography on DEAE-cellulose column and Sephadex G-100 gel filtration. The specific activity was as 67 folds at the fermentation broth, and the yield was 25.5%. The inulinase, containing 13.92% of carbohydrate, was a monomer protein with a molecular weight of 28,000 Dalton; and its isoelectric point was pH 5.4. The optimal pH and temperature of the inulinase was pH 5.0 and 60 degrees C, respectively. The enzyme was strongly inhibited by heavy metal ions of Hg2+, Pb2+ and Cu2+. The optimal substrate for the enzyme was inulin and the product was only fructose, but it also had invertase activity with the I/S of 0.348. The Km and Vm of the inulinase was 6.25 mmol/L and 67.11 mumol.mg-1.min-1, respectively.
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PMID:[Purification and properties of inulinase from Aspergillus niger]. 1118 61


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