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

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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)

A constitutive invertase (EC 3.2.1.26) was isolated and purified by the first time from Pycnoporus sanguineus. The enzyme is a glycoprotein. Its relative molecular mass is about 84,000 and its structure is dimeric, with two identical subunits (about 41,000). The enzyme is able to attack sucrose, raffinose, stachyose, inulin and levan, being sucrose the preferred substrate (Km 4.89 +/- 0.13 mM). Fructose was a classical competitive inhibitor, but glucose was not an inhibitor of the enzyme. Lectins with specificity toward glucose are inhibitors of the enzyme. Glucose was present in invertase acid hydrolysates. Unlike higher plant invertases, bovine serum albumin is not an effector of the Pycnoporus sanguineus enzyme, and the inhibition by fructose is not suppressed by this protein. The properties of the Pycnoporus sanguineus enzyme are discussed with reference to higher plant invertases.
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PMID:Purification and characterization of the invertase from Pycnoporus sanguineus. 766 14

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

Polyamines appear to have an important role in postnatal growth of the rat intestine. In the present study, we examined the effect of spermidine on the maturation of the intestine and on its ability to exclude macromolecules. Two litters of Sprague-Dawley rat pups were assigned to one of four experimental groups. These groups received, on Days 7, 8, and 9, either (a) saline by gavage; (b) spermidine, 0.9 mg (6 mumol) by gavage; (c) cortisone acetate, 3.5 mg i.p.; or (d) saline i.p. On Day 10, animals were fed by gavage with a mixture of bovine serum albumin (BSA; 2 mg/g) and the gamma-globulin fraction of mouse antiovalbumin (anti-OVA) antiserum (1 mg/g) and were bled 4 h later. Intestinal tissues were processed for histologic examination, sucrase determination, and identification of neonatal intestinal Fc receptor (FcRn) by Western blot. Serum immunoreactive BSA (iBSA) and mouse IgG1 and IgG2a anti-OVA antibodies were estimated by enzyme-linked immunosorbent assay. Sucrase activity was elevated in cortisone- and spermidine-treated compared to control rats. iBSA and anti-OVA were significantly reduced in cortisone-treated compared to control rats but were not diminished significantly in the spermidine-treated animals. A decrease in the neonatal intestinal Fc receptor was apparent in the spermidine-fed group; cortisone produced a large reduction in FcRn. Spermidine-fed animals showed morphologic evidence of maturation, with loss of giant vacuoles in the distal intestine; cortisone did not produce significant changes in morphology.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Influence of the polyamine, spermidine, on intestinal maturation and dietary antigen uptake in the neonatal rat. 796 74

Electron microscopy was used to evaluate the function and formation of dense core lysosomes. Lysosomes were preloaded with bovine serum albumin (BSA)-gold conjugates by fluid phase endocytosis using a pulse-chase protocol. The gold particles present in dense core lysosomes and late endosomes were flocculated, consistent with proteolytic degradation of the BSA. A second pulse of BSA-gold also accumulated in the pre-loaded dense core lysosomes at 37 degrees C, but accumulation was reversibly blocked by incubation at 20 degrees C. Time course experiments indicated that mixing of the two BSA-gold conjugates initially occurred upon fusion of mannose 6-phosphate receptor-positive/lysosomal glycoprotein-positive late endosomes with dense core lysosomes. Treatment for 5 hours with wortmannin, a phosphatidyl inositide 3-kinase inhibitor, caused a reduction in number of dense core lysosomes preloaded with BSA-gold and prevented a second pulse of BSA-gold accumulating in them. After wortmannin treatment the two BSA-gold conjugates were mixed in swollen late endosomal structures. Incubation of NRK cells with 0.03 M sucrose resulted in the formation of swollen sucrosomes which were morphologically distinct from preloaded dense core lysosomes and were identified as late endosomes and hybrid endosome-lysosome structures. Subsequent endocytosis of invertase resulted in digestion of the sucrose and re-formation of dense core lysosomes. These observations suggest that dense core lysosomes are biologically active storage granules of lysosomal proteases which can fuse with late endosomes and be re-formed from the resultant hybrid organelles prior to subsequent cycles of fusion and re-formation.
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PMID:Dense core lysosomes can fuse with late endosomes and are re-formed from the resultant hybrid organelles. 937 54

Three fractions with invertase activity (beta-D-fructofuranoside fructohydrolase, EC 3.2.1.26) were isolated from mature Solanum tuberosum tubers: acid soluble invertase, invertase I and invertase II. The first two invertases were purified until electrophoretic homogeneity. They are made by two subunits with an apparent M(r) value of 35,000 and their optimal pH is 4.5. Invertase I was eluted from cell walls with ionic strength while invertase II remained tightly bound to cell walls after this treatment. This invertase was solubilized by enzymatic cell wall degradation (solubilized invertase II). Their K(m)s are 28, 20, 133 and 128 mM for acid soluble invertase, invertase I, invertase II and solubilized invertase II, respectively. Glucose is a non-competitive inhibitor of invertase activities and fructose produces a two site competitive inhibition with interaction between the sites. Bovine serum albumin produces activation of the acid soluble invertase and invertase I while a similar inhibition by lectins and endogenous proteinaceous inhibitor from mature S. tuberosum tubers was found. Invertase II (tightly bound to the cell walls) shows a different inhibition pattern. The test for reassociation of the acid soluble invertase or invertase I on cell wall, free of invertase activity, caused the reappearance of all invertase forms with their respective solubilization characteristics and molecular and kinetic properties. The invertase elution pattern, the recovery of cell wall firmly bound invertase and the coincidence in the immunological recognition, suggest that all three invertases may be originated from the same enzyme. The difference in some properties of invertase II and solubilized invertase II from the other two enzymes would be a consequence of the enzyme microenvironment in the cell wall or the result of its wall binding.
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PMID:Invertase activity associated with the walls of Solanum tuberosum tubers. 1002 94

Uptake of colostrum just after birth is essential to stimulate intestinal growth and function, and in many species, including pigs, colostrum also provides immunological protection via the absorption of immunoglobulin G (IgG). In this study, intestinal growth, IgG absorptive capacity and enzyme activities were investigated in newborn pigs in response to different diets. Newborn piglets were bottle-fed porcine colostrum (PC), bovine colostrum (BC), porcine plasma (PP), porcine milk (PM), bovine colostrum containing porcine plasma (BCP) or a milk replacer (MR) every 3 h (15 mL/kg) for up to 2 d. Bovine serum albumin (BSA) was added to the diets as a macromolecule marker. The percentage of absorbed BSA just after birth was highest for piglets fed the PC diet (30-50%), lower for those fed the BC and BCP diets (23-30%) and lowest for the PP, PM and MR diet-fed piglets (7-20%, P < 0.05 relative to those fed colostrum). Porcine IgG was absorbed more efficiently than bovine IgG. Intestinal closure occurred earlier in MR and BCP piglets (within 12 h after birth) than in PC pigs. At 2 d of age, intestinal mucosal weight (+120% increase from birth) and villus morphology were similar in the PC, BCP and MR groups. All 3 groups also had increased aminopeptidase A activity compared with values at birth (+100% increase). Compared with PC pigs, the BCP group had higher sucrase and maltase activities (+50% and +200%, respectively) and lower aminopeptidase N activity (-50%, P < 0.05). Similarly, MR pigs showed elevated sucrase activity (+40%) and lowered maltase, lactase and aminopeptidase N activities (-20% to -50%, P < 0.05) compared with PC pigs. We conclude that porcine and bovine colostrum contain factors that stimulate the intestinal endocytotic and enzymatic capacity in newborn pigs. A milk replacer can produce normal gut growth, but may be inefficient in mediating normal macromolecule transport and disaccharidase activity. Bovine colostrum mixed with porcine plasma proteins may be a useful substitute for porcine colostrum in artificial rearing of newborn pigs.
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PMID:Development of intestinal immunoglobulin absorption and enzyme activities in neonatal pigs is diet dependent. 1173 77

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.
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PMID:Influence of mannan epitopes in glycoproteins--Concanavalin A interaction. Comparison of natural and synthetic glycosylated proteins. 1229 32

Poly(maleic anhydride-alt-hexen-1)(poly(MA-alt-H-1)) has been synthesized by radical polymerization and characterized by DSC, FT-IR, acid number determination, viscometric and NMR methods. Data showed that the co-polymer is an alternating co-polymer whose composition does not depend on the monomer feed composition. Invertase was immobilized onto a poly(MA-alt-H-1) membrane via glutaraldehyde and bovine serum albumin. The Km value of poly(MA-alt-H-1)-invertase was approximately 4.4-fold higher than the free enzyme, indicating decreased affinity by the invertase for its substrate (sucrose), whereas Vmax was lower for the immobilized invertase. Immobilization improved the pH stability of the enzyme, as well as its temperature stability. Immobilized samples obtained were stable and could be used many times over a period of 2 months without considerable activity loss.
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PMID:Preparation and properties of invertase immobilized on a poly(maleic anhydride-hexen-1) membrane. 1690 48

A poly(acrylic acid)-polyethylene graft copolymer was prepared and used initially to couple to acid phosphatase, using soluble carbodiimides. Yields which were quite good were obtained with CMC but not with EDAC. The copolymers was used to couple trypsin using EEDQ. Several organic solvents were investigated for the preparation of the "activated" poly(acrylic acid) intermediate. Using the activated system, high concentrations of trypsin were bound but the relative activities were not very high. The yield was good with bovine serum albumin (BSA). When the method was used for invertase, acid phosphatase, and alkaline phosphatase, the yields were poor and the copolymer was shown to absorb protein by an ion-exchange mechanism. However, the activated system gave a good yield of coupling to phenylpropylamine. A polyethylene-coacrylic-acid polymer containing 13% of acrylic acid (by weight) was then converted to the acid chloride by refluxing with thionyl chloride. The chlorinated copolymer which contained 0.7% chlorine and a thionyl-chloride-treated polyethylene control which contained no chlorine were investigated in immobilization studies. Such coupling involved bovine serum albumin (BSA), alkaline phosphatase, trypsin, beta-galactosidase, and invertase. Bovine serum albumin coupled well to the support, but none of the enzymes gave high levels of enzymes activity. Phenylpropylamine coupled well and all of the acid chloride groups were involved. Tyrosine reacted with 63% of the available acid chloride groups.
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PMID:The immobilizaton of enzymes, bovine serum albumin, and phenylpropylamine to poly(acrylic acid)-polyethylene-based copolymers. 1854 30

Polyclonal antibodies directed against the yeast invertase glycosyls were raised by immunizing rabbits with neoglycoprotein-I and neoglycoprotein-II. The neoglycoproteins were prepared by separately coupling the N-linked large and small molecular weight yeast invertase oligosaccharides respectively to bovine serum albumin with the help of glutaraldehyde. Antibodies specifically recognizing the invertase oligosaccharides were purified from the sera of rabbits immunized with either neoglycoprotein using an affinity column of sepharose 4B-linked yeast invertase. Specific immunoaffinity supports for the immobilization of invertase were constructed by coupling the affinity-purified antineoglycoprotein-I or antineoglycoprotein-II antibodies to cyanogen bromide activated sepharose-4B. Both the affinity adsorbants were effective in binding and improving the thermal stability of invertase. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 605-609, 1997.
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PMID:Immobilization of invertase on sepharose-linked enzyme glycosyl recognizing polyclonal antibodies. 1864 31


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