Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.2.1.26 (invertase)
4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

All the non-pathogenic strains of Escherichia coli tested failed to synthesize invertase. However, among the pathogenic E. coli, only 11% of them synthesized the enzyme. Invertase synthesis was best at pH 8.0, when the sole nitrogen source was peptone. The enzyme was induced by sucrose but repressed by glucose and fructose. The enzyme was partially purified by ammonium sulphate precipitation, followed by dialysis and gel permeation chromatography. The partially purified invertase possessed a molecular weight of 125,000 KD and an apparent km of approximately 2.94mM for sucrose. The enzyme was stimulated by Ca++ and Mg++, inhibited by Cu++, U++, IAA and exhibited optimum activity at pH 6.5 at 40 degrees C.
...
PMID:The purification and characterization of intracellular invertase obtained from pathogenic Escherichia coli. 760 57

The enzyme levanase encoded by the sacC gene from Bacillus subtilis was overexpressed in Escherichia coli with the strong, inducible tac promoter. The enzyme was purified from crude E. coli cell lysates by salting out with ammonium sulfate and chromatography on DEAE-Sepharose CL-6B, S-Sepharose, and MonoQ-Sepharose. The purified protein had an apparent molecular mass of 75,000 Da in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which is in agreement with that expected from the nucleotide sequence. Levanase was active on levan, inulin, and sucrose with Km values of 1.2 microM, 6.8 mM, and 65 mM, respectively. The pH optimum of the enzyme acting on inulin was 5.5, and the temperature optimum was 55 degrees C. Levanase was rapidly inactivated at 60 degrees C, but activity could be retained for longer times by adding fructose or glycerol. The enzyme activity was completely inactivated by Ag+ and Hg2+ ions, indicating that a sulfhydryl group is involved. A ratio of sucrase to inulinase activity of 1.2 was found for the purified enzyme with substrate concentrations of 50 mg/ml. The mechanism of enzyme action was investigated. No liberation of fructo-oligomers from inulin and levan could be observed by thin-layer chromatography and size exclusion chromatography-low-angle laser light scattering-interferometric differential refractive index techniques. This indicates that levanase is an exoenzyme acting by the single-chain mode.
...
PMID:Purification and characterization of the Bacillus subtilis levanase produced in Escherichia coli. 764 30

beta-Fructofuranosidase activities of eight strains of Bifidobacteria, intestinal bacteria, were assayed and Bifidobacterium infantis was selected for purification of the enzyme. beta-Fructofuranosidase activity was recovered in the supernatant fraction after disruption of B. infantis cells with sonication and was purified to homogeneity by ammonium sulfate fractionation, and DEAE-cellulose, butyl-Toyopearl and Sephacryl S-300 column chromatographies. The enzyme (molecular weight (M.W.) 232000) was composed of three identical subunits (M.W. 75000) whose NH2-terminal amino acids were threonine. The enzyme was stable at pH 6-8, having the optimum activity at pH 6.0-6.2. The enzyme activity was stable under 40 degrees C and the optimal temperature was 55 degrees C. This enzyme catalyzed the hydrolysis of sucrose, 1-kestose, nystose, inulin and raffinose at the relative velocities of 100, 297, 365, 140 and 3.8, respectively, but did not catalyze the hydrolysis of maltose or cellobiose. These results indicated that this fructooligosaccharide hydrolyzing enzyme is a novel type of beta-fructofuranosidase.
...
PMID:Purification and characterization of beta-fructofuranosidase from Bifidobacterium infantis. 792 Apr 15

The mode of sucrose utilisation by Corynebacterium murisepticum cells growing on M9 minimal medium supplemented with 0.4% sucrose as the carbon source was studied. It was observed that during growth of this organism, sucrose in the medium is hydrolysed to glucose and fructose, suggesting the formation of an extracellular invertase. Unlike in other microorganisms (e.g. Saccharomyces cerevisiae) the invertase formation is not repressed by the presence of glucose in the medium. The invertase was found to be the only predominant extracellular protein in the culture broth and could be purified in a single step by precipitation at 90% ammonium sulphate saturation. The purified protein had a molecular mass of 70,000 daltons. It not only showed invertase activity, but also a fructosyltransferase activity as it could convert sucrose to beta-1,2-difructose, as well as to glucose and fructose.
...
PMID:An invertase with unusual properties secreted by sucrose-grown cells of Corynebacterium murisepticum. 840 45

The 450 kDa cellobiase from Termitomyces clypeatus which migrates as a single band on IEF, PAGE and SDS-PAGE, was found to possess appreciable sucrase activity. The fungus produced sucrase and cellobiase constitutively in different media but with different activity ratios. The kinetics of secretion of the two enzymes was similar under in vivo and in vitro conditions. HPGPLC analysis of the culture filtrates indicated the presence of both sucrase and cellobiase in the same protein fractions of different molar mass, even in the 30-kDa protein fraction. No free sucrase or cellobiase could be detected in the culture filtrates. It was also observed that fractionation of cellobiase by (NH4)2SO4 precipitation was different with different amounts of associated sucrase activity present in the culture filtrate. The (NH4)2SO4-precipitated cellobiase fraction also contained cellobiases in proteins of widely varied molar mass ranges. However, none of the low-molar mass proteins other than the 450-kDa enzyme could be purified, as all low-molar-mass fractions spontaneously aggregated to the 450-kDa enzyme. Hydrophobic chromatography of the (NH4)2SO4-precipitated fractions followed by HPGPLC of the eluted active fraction yielded both cellobiase-free sucrase and a very low sucrase-containing cellobiase fraction. The cellobiase fraction, homogeneous in PAGE, was also a high-molar-mass protein complex dissociating into a number of protein bands on SDS-PAGE.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Development of high-molar-mass cellobiase complex by spontaneous protein-protein interaction in the culture filtrate of Termitomyces clypeatus. 854 93

Multiple isoforms of beta-fructofuranosidase (invertase, EC 3.2.1.26) were identified in mature green leaves of the cruciferous plant Arabidopsis thaliana (L.) Heynh. There were four major and one minor isoforms of soluble acid invertase and an additional activity which could be released from the cell wall by buffers of high ionic strength. This study reports the separation and characterisation of three soluble isoforms following ammonium sulphate and polyethylene glycol 6000 precipitations, Concanavalin A, MonoQ ion exchange, Superose 12 size-exclusion chromatography and chromatofocusing. These isoforms, designated INV1, INV2 and INV3, had isoelectric points of 4.75, 4.70 and 4.65 and a Km for sucrose of 5, 12 and 5 mM, respectively. Each had a pH optimum of 5.5, exhibited optimal activity at 45 degrees C and used sucrose as the preferred substrate. All fractions containing these isoforms contained a 52-kDa polypeptide which was specifically detected by immunoblotting with an antibody raised against deglycosylated wheat invertase. The N-terminal amino-acid sequence of this polypeptide was homologous to acid invertases isolated from other plant species. The possible origin of isoforms of soluble acid invertase is discussed.
...
PMID:Purification and characterisation of soluble invertases from leaves of Arabidopsis thaliana. 858 Jul 69

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.
...
PMID:Purification and properties of beta-fructofuranosidase from Clostridium perfringens. 914 17

Neutral invertase from nodules of chickpea (Cicer arietinum L.) was isolated and purified by ammonium sulphate fractionation, gel filtration and DEAE-cellulose column chromatography. The purified enzyme was stable between 0 to 40 degrees C beyond which it was irreversibly denatured. Optimum temperature and pH of the enzyme were 37 degrees C and 7.0, respectively. K(m) for sucrose was 14.2 mM and Vmax was 4.8 mumole hr-1. The enzyme was inhibited by several metal ions. From the temperature effect on K(m) and Vmax values, the energy of activation (Ea), enthalpy change (delta H) and entropy change (delta S) of the enzyme were calculated to be 147 kJmol-1, -4.10 kJmol-1 and -2.33 JK-1mol-1, respectively. By employing photo-oxidation and chemical modification and by studying the effect of pH on K(m) and Vmax, the involvement of sulphydryl-, imidazole- and alpha-amino groups in the active site of the enzyme has been indicated.
...
PMID:Purification and characterization of neutral invertase from chickpea nodules. 959 35

Beta recombinase, a DNA resolvase-invertase, catalyzes in the presence of a chromatin-associated protein such as Hbsu, DNA resolution or DNA inversion on supercoiled substrates containing two directly or inversely oriented target (six) sites. Single crystals of the beta recombinase from plasmid pSM19035 were obtained using the vapor diffusion technique with ammonium phosphate as the precipitating agent. The crystals diffracted X-rays to a maximum resolution of 2.5A. Due to proteolytic degradation during the crystallization experiment, the crystals contain only the N-terminal catalytic domain of beta recombinase corresponding to about 60% of the molecular mass of the initially assayed native protein. The proteolytic removal of the C-terminal DNA-binding domain demonstrated that protein modification can be essential to provide material suitable for X-ray analysis.
...
PMID:Proteolytic cleavage of gram-positive beta recombinase is required for crystallization. 1036 Sep 76

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.
...
PMID:[Purification and properties of inulinase from Aspergillus niger]. 1118 61


<< Previous 1 2 3 4 5 6 7 Next >>

---