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Enzyme
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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)
Fructosyltransferase (EC.2.4.1.9) and
invertase
(EC.3.2.1.26) have been purified from the crude extract of Aspergillus niger AS0023 by successive chromatographies on DEAE-sephadex A-25, sepharose 6B, sephacryl S-200, and concanavalin A-Sepharose 4B columns. On acrylamide electrophoresis the two enzymes, in native and denatured forms, gave diffused glycoprotein bands with different electrophoretic mobility. On native-PAGE and SDS-PAGE, both enzymes migrated as polydisperse aggregates yielding broad and diffused bands. This result is typical of heterogeneous glycoproteins and the two enzymes have proved their glycoprotein nature by their adsorption on concanavalin A
lectin
. Fructosyltransferase (FTS) on native PAGE migrated as two enzymatically active bands with different electrophoretic mobility, one around 600 kDa and the other from 193 to 425 kDa. On SDS-PAGE, these two fractions yielded one band corresponding to a molecular weight range from 81 to 168 kDa. FTS seems to undergo association-dissociation of its glycoprotein subunits to form oligomers with different degrees of polymerization. Invertase (INV) showed higher mobility corresponding to a molecular range from 82 to 251 kDa, on native PAGE, and from 71 to 111 kDa on SDS-PAGE. The two enzymes exhibited distinctly different pH and temperature profiles. The optimum pH and temperature for FTS were found to be 5.8 and 50 degrees C, respectively, while INV showed optimum activity at pH 4.4 and 55 degrees C. Metal ions and other inhibitors had different effects on the two enzyme activities. FTS was completely abolished with 1 mM Hg(2+) and Ag(2+), while INV maintained 72 and 66% of its original activity, respectively. Furthermore, the two enzymes exhibited distinctly different kinetic constants confirming their different nature. The K(m) and V(m) values for each enzyme were calculated to be 44.38 mM and 1030 micromol ml(-1)min(-1) for FTS and 35.67 mM and 398 micromol ml(-1) min(-1) for INV, respectively. FTS and INV catalytic activity was dependent on sucrose concentration. FTS activity increased with increasing sucrose concentrations, while INV activity decreased markedly with increasing sucrose concentration. Furthermore, INV exhibited only hydrolytic activity producing exclusively fructose and glucose from sucrose, while FTS catalyzed exclusively fructosyltransfer reaction producing glucose, 1-kestose, nystose and fructofuranosyl nystose. In addition, at 50% sucrose concentration FTS produced fructooligosaccharides at the yield of 62% against 54% with the crude extract.
...
PMID:Purification and partial characterization of fructosyltransferase and invertase from Aspergillus niger AS0023. 1093 62
This work describes a new
invertase
proteinaceous inhibitor from Cyphomandra betacea Sendt. (tomate de arbol) fruits. The proteinaceous inhibitor was isolated and purified from a cell wall preparation. The pH stability, kinetics of the inhibition of the C. betacea
invertase
, inhibition of several higher plant invertases and
lectin
nature of the inhibitor were studied. The inhibitor structure involves a single polypeptide (Mr = 19000), as shown by gel filtration and SDS-PAGE determinations. N-terminal aminoacid sequence was determined. The properties and some structural features of the inhibitor are compared with the proteinaceous inhibitors from several plant species (Beta vulgaris L., Ipomoea batatas L. and Lycopersicon esculentum Mill.). All these inhibitors share lectinic properties, some common epitopes, some aminoacid sequences and a certain lack of specificity towards invertases of different species, genera and even plant family. In consequence, the inhibitors appear to belong to the same
lectin
family. It is now known that some lectins are part of the defence mechanism of higher plants against fungi and bacteria and this is a probable role of the proteinaceous inhibitors.
...
PMID:Invertase proteinaceous inhibitor of Cyphomandra betacea Sendt fruits. 1114 Jun 13
We purified sucrase-isomaltase and
sucrase
-free isomaltase from a normal and a
sucrase
-deficient line, respectively, of the house musk shrew Suncus murinus and examined the effects of mutation on enzyme structure and activities. Recent cDNA cloning studies have predicted that
sucrase
-free mutant isomaltase lacks the C-terminal 69 amino acids of normal isomaltase, as well as the entire
sucrase
. On SDS-polyacrylamide gel electrophoresis purified
sucrase
-free isomaltase gave a single protein band of 103 kDa, while sucrase-isomaltase gave two major protein bands of 106 and 115 kDa. The 115, but not 106, kDa band was quite similar to the 103 kDa band on Western blotting with Aleuria aurantia
lectin
and antibody against shrew sucrase-isomaltase, suggesting that the 115 and 103 kDa bands are due to normal and mutant isomaltases, respectively, in accordance with the above prediction. Purified isomaltase and sucrase-isomaltase were similar in Km and Vmax (based on isomaltase mass) values for isomaltose hydrolysis and in inhibition of isomaltase activity by antibody against rabbit sucrase-isomaltase, suggesting that the enzymatic properties of isomaltase are mostly unaffected by mutation.
...
PMID:Comparison of sucrase-free isomaltase with sucrase-isomaltase purified from the house musk shrew Suncus murinus. 1134 43
Use of lectins as ligands for the immobilization and stabilization of glycoenzymes has immense application in enzyme research and industry. But their widespread use could be limited by the high cost of their production. In the present study preparation of a novel and inexpensive
lectin
support for use in the immobilization of glycoenzymes containing mannose or glucose residues in their carbohydrate moiety has been described. Cajanus cajan
lectin
(CCL) coupled covalently to cyanogen bromide activated Seralose 4B could readily bind enzymes such as
invertase
, glucoamylase and glucose oxidase. The immobilized and glutaraldehyde crosslinked preparations of
invertase
exhibited high resistance to inactivation upon exposure to enhanced temperature, pH, denaturants and proteolysis. Binding of
invertase
to CCL-Seralose was however found to be readily reversible in the presence of 1.0 M methyl alpha-D mannopyranoside. In a laboratory scale column reactor the CCL-Seralose bound
invertase
was stable for a month and retained more than 80% of its initial activity even after 60 days of storage at 4 degrees C. CCL-Seralose bound
invertase
exhibited marked stability towards temperature, pH changes and denaturants suggesting its potential to be used as an excellent support for the immobilization of other glycoenzymes as well.
...
PMID:Immobilization and stabilization of invertase on Cajanus cajan lectin support. 1148 Sep 20
The present investigation characterized the effect of red kidney bean
lectin
exposure on gut maturation and function in young piglets. Eleven suckling pigs were given by stomach tube a crude red kidney bean
lectin
preparation (containing about 25%
lectin
, 400 mg/kg BW) (
lectin
-treated pigs) at 10, 11, and 12 d of life, and an additional 16 pigs (control pigs) were given saline instead. On the next day, the intestinal absorptive capacity was determined in vivo, and on the 14th d of life the piglets were killed and organs and small intestine samples were collected for analyses and in vitro permeability experiments. The
lectin
-treated pigs showed an increase in stomach weights and mucosa thickness, whereas no weight effect was found for the small intestine, spleen, liver, or adrenals. Morphometric analyses of the small intestine in
lectin
-treated pigs showed a decrease in villus heights, an increase in crypt depths and crypt cell mitotic indices, and fewer vacuolated enterocytes per villus and reduced vacuole size. Lectin treatment also resulted in a decrease in the absorption of different-sized marker molecules after gavage feeding, a decrease in intestinal marker permeability, and a change in small intestinal disaccharidase activities, with increased maltase and
sucrase
activities. The size of the pancreatic acini was also greater in the
lectin
-treated pigs, but no increases in enzyme content or pancreatic weight could be determined. In addition, the blood plasma levels of cholecystokinin were higher in the
lectin
-treated than in the control pigs. The results indicate that exposure to crude red kidney bean
lectin
induces structural and functional maturation of the gut and pancreatic growth in young suckling piglets. This possibility of inducing gut maturation may lead to an improvement in the piglets' ability to adapt to weaning and to an increase in the growth and health of these animals.
...
PMID:Enteral exposure to crude red kidney bean lectin induces maturation of the gut in suckling pigs. 1172 47
Two natural glycoproteins/glycoenzymes,
invertase
and glucoamylase, and two neoglycoconjugates, synthetized from Saccharomyces cerevisiae mannan, bovine serum albumin and penicillin G acylase were tested for interaction with
lectin
Concanavalin A (Con A). The interaction of natural and synthetic glycoproteins with Con A was studied using three different experimental methods: (i). quantitative precipitation in solution (ii). sorption to Con A immobilized on bead cellulose; and (iii). kinetic measurement of the interaction by surface plasmon resonance. Prepared neoglycoproteins were further characterized: saccharide content, molecular weight, polydispersion, kinetic and equilibrium association constants with Con A were determined. It can be concluded that the used conjugation method proved to be able to produce neoglycoproteins with similar properties like natural glycoproteins, i.e. enzymatic activity (protein part) and
lectin
binding activity (mannan part) were preserved and the neoglycoconjugates interact with Con A similarly as natural mannan-type glycoproteins.
...
PMID:Influence of mannan epitopes in glycoproteins--Concanavalin A interaction. Comparison of natural and synthetic glycosylated proteins. 1229 32
A
lectin
was purified from rhizomes of the fern Phlebodium aureum by affinity chromatography on mannose-Sepharose. The
lectin
, designated P. aureum
lectin
(PAL), is composed of two identical subunits of approximately 15 kDa associated by noncovalent bonds. From a cDNA library and synthetic oligonucleotide probes based on a partial amino acid sequence, 5'- and 3'-rapid amplification of cDNA ends allowed the generation of two similar full-length cDNAs, termed PALa and PALb, each of which had an open reading frame of 438 bp encoding 146 amino acid residues. The two proteins share 88% sequence identity and showed structural similarity to jacalin-related lectins. PALa contained peptide sequences exactly matching those found in the isolated
lectin
. PALa and PALb were expressed in Escherichia coli using pET-22b(+) vector and purified by one-step affinity chromatography. Native and recombinant forms of PAL agglutinated rabbit erythrocytes and precipitated with yeast mannan, dextran, and the high mannose-containing glycoprotein
invertase
. The detailed carbohydrate-binding properties of the native and recombinant lectins were elucidated by agglutination inhibition assay, and native
lectin
was also studied by isothermal titration calorimetry. Based on the results of these assays, we conclude that this primitive vascular plant, like many higher plants, contains significant quantities of a mannose/glucose-binding protein in its storage tissue, whose binding specificity differs in detail from either legume mannose/glucose-binding lectins or monocot mannose-specific lectins. The identification of a jacalin-related
lectin
in a true fern reveals for the first time the widespread distribution and molecular evolution of this
lectin
family in the plant kingdom.
...
PMID:Purification, characterization, molecular cloning, and expression of novel members of jacalin-related lectins from rhizomes of the true fern Phlebodium aureum (L) J. Smith (Polypodiaceae). 1253 84
Detecting the use of genetically modified feeds in milk has become important, because the voluntary labeling of milk and dairy products as "GMO free" or as "organically grown" prohibits the employment of genetically modified organisms (GMOs). The aim of this work was to investigate whether a DNA transfer from foodstuffs like soya and maize was analytically detectable in cow's milk after digestion and transportation via the bloodstream of dairy cows and, thus, whether milk could report for the employment of transgene feeds. Blood, milk, urine, and feces of dairy cows were examined, and foreign DNA was detected by polymerase chain reaction by specifically amplifying a 226-bp fragment of the maize
invertase
gene and a 118-bp fragment of the soya
lectin
gene. An intravenous application of purified plant DNA showed a fast elimination of marker DNA in blood or its reduction below the detection limit. With feeding experiments, it could be demonstrated that a specific DNA transfer from feeds into milk was not detectable. Therefore, foreign DNA in milk cannot serve as an indicator for the employment of transgene feeds unless milk is directly contaminated with feed components or airborne feed particles.
...
PMID:Model studies on the detectability of genetically modified feeds in milk. 1259 93
Multiplex PCR procedures were developed for simultaneously detecting multiple target sequences in genetically modified (GM) soybean (Roundup Ready), maize (event 176, Bt11, Mon810, T14/25), and canola (GT73, HCN92/28, MS8/RF3, Oxy 235). Internal control targets (
invertase
gene in corn,
lectin
and beta-actin genes in soybean, and cruciferin gene in canola) were included as appropriate to assess the efficiency of all reactions, thereby eliminating any false negatives. Primer combinations that allowed the identification of specific lines were used. In one system of identification, simultaneous amplification profiling (SAP), rather than target specific detection, was used for the identification of four GM maize lines. SAP is simple and has the potential to identify both approved and nonapproved GM lines. The template concentration was identified as a critical factor affecting efficient multiplex PCRs. In canola, 75 ng of DNA template was more effective than 50 ng of DNA for the simultaneous amplification of all targets in a reaction volume of 25 microL. Reliable identification of GM canola was achieved at a DNA concentration of 3 ng/microL, and at 0.1% for GM soybean, indicating high levels of sensitivity. Nonspecific amplification was utilized in this study as a tool for specific and reliable identification of one line of GM maize. The primer cry1A 4-3' (antisense primer) recognizes two sites on the DNA template extracted from GM transgenic maize containing event 176 (European corn borer resistant), resulting in the amplification of products of 152 bp (expected) and 485 bp (unexpected). The latter fragment was sequenced and confirmed to be Cry1A specific. The systems described herein represent simple, accurate, and sensitive GMO detection methods in which only one reaction is necessary to detect multiple GM target sequences that can be reliably used for the identification of specific lines of GMOs.
...
PMID:Reliable detection and identification of genetically modified maize, soybean, and canola by multiplex PCR analysis. 1312 80
The main objective of this study was to determine the effect of fiber source and concentration on morphological characteristics, mucin staining pattern, and mucosal enzyme activities in the gastrointestinal tract of pigs. The experiment included 50 pigs from 10 litters weaned at 4 wk of age (BW 8.6 +/- 1.4 kg) and divided into 5 treatment groups. Diets containing fiber of various physico-chemical properties and concentrations were formulated to contain 73, 104, or 145 g of dietary fiber/kg of DM. The diets were based on raw wheat and barley flours. Pectin and barley hulls, representing soluble and insoluble fiber sources, respectively, were used to increase the fiber concentration. The pigs were fed the experimental diets for 9 d, and then the pigs were euthanized and the entire gastrointestinal tract was removed. Tissue samples were taken from the mid and distal small intestine and from the mid colon. Inclusion of pectin in the diets significantly decreased (P < 0.001) ADFI and ADG compared with pigs fed no pectin. The villi and the crypts were shorter in pigs fed pectin-containing diets, but the villous height/crypt depth ratio was unaltered. Pectin significantly decreased the area of mucins in the crypts of the small intestine, indicating that the pigs fed the pectin-containing diet would probably be more susceptible to pathogenic bacteria, although this cannot be separated from the impact on ADFI. The
lectin
-binding pattern of the intestinal mucosa was unaffected by diet. The activity of lactase and maltase was increased in pigs fed diets with high fiber content, whereas
sucrase
activity was increased in pigs fed the pectin-containing diets. The activity of the peptidases, aminopeptidase N and dipeptidylpeptidase IV, was increased when feeding high fiber diets, whereas the activity of gamma-glutamyl transpeptidase remained unaffected by the experimental diets. In conclusion, the reduced feed intake observed with the pectin-containing diets could explain the lower villous height and crypt depth observed in this study. However, direct effects of pectin also are possible, and thus further study is warranted. Feeding pigs high insoluble fiber diets improved gut morphology by increasing villi length and increased mucosal enzyme activity when compared with pigs fed pectin-containing diets. The mucin content as determined by staining characteristics suggests that pigs fed high insoluble fiber diets might be better protected against pathogenic bacteria than pigs fed diets high in soluble fiber.
...
PMID:Intestinal morphology and enzymatic activity in newly weaned pigs fed contrasting fiber concentrations and fiber properties. 1669 94
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