Acid and Neutral Invertases in the Mesocarp of Developing Muskmelon (Cucumis melo L. cv Prince) Fruit

Acid and neutral invertases were found in the mesocarp of developing muskmelon (Cucumis melo L. cv Prince) fruit and the activities of these enzymes declined with maturation of the fruit, concomitantly with the accumulation of sucrose. Neutral invertase was only present in the soluble fraction and acid invertase was present in both the soluble and cell-wall fractions. The cell-wall fraction contained three types of acid invertase: a NaCl-released invertase; an EDTA-released invertase, and a tightly bound invertase that still remained on the cell wall after treatment with NaCl and EDTA. The soluble acid and neutral invertases could be separated from one another by chromatography on DEAE-cellulose and they exhibited clear differences in their properties, namely, in their pH optima, substrate specificity, K_m values for sucrose, and inhibition by metal ions. The EDTA-released invertase and the soluble acid invertase were similar with regard to their chromatographic behavior on DEAE-cellulose, but the NaCl-released invertase was different because it was adsorbed to a column of CM-cellulose. The soluble acid invertase and two cell-wall bound invertases had very similar characteristics with regard to optimal pH and temperature, K_m value for sucrose, and substrate specificity.     

The structural genes of internal invertases in Saccharomyces cerevisiae.

Summary Polyacrylamide gel electrophoresis (without SDS) of invertases from strains each carrying only one of the five known SUC-genes revealed differences in mobility of the internal enzymes. SUC1 invertase moved distinctly slower than the invertases formed in the presence of genes SUC2 to SUC5. Three bands of internal invertase activity were found in diploids carrying both SUC1 (slow invertase) and one of the other SUC-genes (fast invertases). Tetrad analysis of such diploids yielded haploids which showed the same three bands if they carried SUC1 in combination with another SUC gene. A gene dosage effect was observed in relation to invertase activity in haploid strains with only gene SUC1 or only SUC4 on one hand, and both genes on the other hand. A sucrose non-fermenting and invertase negative strain with mutant allele suc3-3 of gene SUC3 (fast invertase) was crossed with SUC1. The heterozygous diploid and the recombinant haploids (SUC1 suc3-3) showed two bands in the region of the internal invertase: a slow SUC1 band and a second band corresponding to the intermediate band of SUC1-SUC3 strains. The intermediate band in SUC1 suc3-3 strains is considered as a hybrid consisting of an active SUC1-monomer and an inactive suc3-mutant monomer. Formation of such hybrid bands was taken as evidence for the structural nature of SUC-genes.     

Purification, Biochemical and Immunological Characterization of Acid Invertases from Apple Fruit

The soluble acid invertase (SAI) and cell wall-bound invertase (CWI) were purified from apple fruit to apparent electrophoretic homogeneity. Based on sequencing, substrate specificity, and immunoblotting assay, the purified enzymes were identified to be two isoforms of acid invertase (β-fructosidase; EC 3.2.1.26). The SAI and CWI have the same apparent molecular mass with a holoenzyme of molecular mass of 220 kDa composed of 50 kDa subunits. The SAI has a lower Km value for sucrose and higher Km for raffinose compared with CWI. These acid invertases differ from those in other plants in some of their biochemical properties, such as the extremely high Km value for raffinose, no hydrolytic activity for stachyose, and a mixed form of inhibition by fructose to their activity. The antibodies directed against the SAI and CWI recognized, from the crude extract, three polypeptides with a molecular mass of 50, 68, and 30 kDa, respectively.These results provide a substantial basis for the further studies of the acid invertases in apple fruit.     

Characterization of a Mutant from Lactobacillus amylovorus JCM 1126T with Improved Utilization of Sucrose

A strain YF43, which can grow on sucrose as rapidly as glucose, was isolated by mutation from Lactobacillus amylovorus JCM 1126, the type strain defective in sucrose utilization. Exogenous sucrose stimulated the production of invertase by strains YF43 and JCM 1126 simultaneously. In a medium containing fructooligosaccharide as the sole carbon source, the cells of strain YF43 showed high invertase activity in spite of poor growth. The two invertases produced in the cells grown on sucrose and fructooligosaccharide were an identical β-fructofuranosidase, as judged from properties of partially purified enzymes. These observations indicated that strain YF43 is a mutant improved for permeation of sucrose and not derepressed for the synthesis of invertase. Received: 23 May 2000 / Accepted: 26 June 2000     

Purification and characterization of three soluble invertases from barley (Hordeum vulgare L.) leaves.

Three soluble isoforms of invertase (beta-fructofuranosidase; EC 3.2.1.26) were purified from 7-d-old primary leaves of barley (Hordeum vulgare L.). Invertase I, a monomeric protein of 64 kD, was purified to apparent homogeneity as shown by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Invertases IIA and IIB, multimeric proteins with molecular masses of the 116 and 155 kD, were purified 780- and 1370-fold, respectively, but were not yet homogeneous. Extracts of epidermal strips of leaves contained only invertase IIB. The specific activity of invertase was more than 100-fold higher in the epidermis than in the mesophyll. All three isoforms were acidic invertases, with pH optima of around 5.0 and little activity in the alkaline range. Invertase I had a Km for sucrose of 8.1 mM, and invertases IIA and IIB had much lower values of 1.0 and 1.7 mM, respectively. Invertase I was more than 2-fold more resistant than the other two invertases to the inhibitors HgCl2 and pyridoxal. All three constitutive invertases were found to act also as sucrose-sucrose fructosyltransferases when supplied with high concentrations of sucrose, forming 1-kestose as principal product. However, the fructosyltransferase activity of all three enzymes was inhibited by pyridoxal in the same way as their invertase activity. This characteristic clearly differentiates them from the inducible sucrose-sucrose fructosyltransferase of barley leaves, the activity responsible for the initial steps of fructan biosynthesis, which has previously been shown to be insensitive to pyridoxal.     

Invertases of carnation petals. Partial purification, characterization and changes in activity during petal growth

Carnation ( Dianthus caryophyllus L. cv. White Sim) petals contained two distinct invertases (EC 3.2.1.26) based on chromatographic behavior on DEAE-cellulose. Both are soluble in 20 m M sodium phosphate buffer (pH 6.5) and exhibit acid pH optimum of 5.5. Extraction of a cell wall preparation from petals with 1 M NaCl released little additional activity. Furthermore, only traces of activity remained associated with the NaCl-extracted cell wall preparation. One of the soluble invertases, representing over 75% of the total activity, was partially purified by (NH₄)₂SO₄ fractionation and sequential chromatography over diethylaminoethyl-cellulose, concanavalin-A sepharose and polyacrylamide P-200. The enzyme was purified 38-fold with a recovery of 12%. It had an apparent native molecular weight of 215 kDa. The partially purified invertase is a β-fructofuranosidase (EC 3.2.1.26) based on its specificity for sucrose. The K_m for sucrose was 3.3 m M . Accumulation of reducing sugars and increased invertase activity during expansive petal growth indicates that sucrose is the major source of carbon for petal growth.     

Purification and Characterization of Soluble (Cytosolic) and Bound (Cell Wall) Isoforms of Invertases in Barley (Hordeum vulgare) Elongating Stem Tissue

Three different isoforms of invertases have been detected in the developing internodes of barley (Hordeum vulgare). Based on substrate specificities, the isoforms have been identified to be invertases (β-fructosidases EC 3.2.1.26). The soluble (cytosolic) invertase isoform can be purified to apparent homogeneity by diethylaminoethyl cellulose, Concanavalin-A Sepharose, organomercurial Sepharose, and Sephacryl S-300 chromatography. A bound (cell wall) invertase isoform can be released by 1 molar salt and purified further by the same procedures as above except omitting the organo-mercurial Sepharose affinity chromatography step. A third isoform of invertase, which is apparently tightly associated with the cell wall, cannot be isolated yet. The soluble and bound invertase isoforms were purified by factors of 60- and 7-fold, respectively. The native enzymes have an apparent molecular weight of 120 kilodaltons as estimated by gel filtration. They have been identified to be dimers under denaturing and nondenaturing conditions. The soluble enzyme has a pH optimum of 5.5, K_m of 12 millimolar, and a V_max of 80 micromole per minute per milligram of protein compared with cell wall isozyme which has a pH optimum of 4.5, K_m of millimolar, and a V_max of 9 micromole per minute per milligram of protein.     

Growth and Sucrose Metabolism of Carrot Callus Strains with Normal and Low Acid Invertase Activity

The properties of two strains of carrot (Daucus carota) callus are presented. One has a very low acid invertase activity which is accompanied by differences in morphology and metabolic rate, but not in growth rate. We conclude that one of the main functions of plant acid invertases is in controlling the levels of sugars which, by interaction with hormones, affect differentiation, both morphological and biochemical. The effect of tris on sucrose metabolizing enzymes, and the cause of the “sucrose effect” are considered.     

Invertase activity associated with the walls of Solanum tuberosum tubers

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.     

Purification, Biochemical and Immunological Characterization of Acid Invertases from Apple Fruit

The soluble acid invertase (SAI) and cell wall-bound invertase (CWI) were purified from apple fruit to apparent electrophoretic homogeneity. Based on sequencing, substrate specificity, and immunoblotting assay, the purified enzymes were identified to be two isoforms of acid invertase (β-fructosidase; EC 3.2.1.26). The SAI and CWI have the same apparent molecular mass with a holoenzyme of molecular mass of 220 kDa composed of 50 kDa subunits. The SAI has a lower Km value for sucrose and higher Km for raffinose compared with CWI. These acid invertases differ from those in other plants in some of their biochemical properties, such as the extremely high Km value for raffinose, no hydrolytic activity for stachyose, and a mixed form of inhibition by fructose to their activity. The antibodies directed against the SAI and CWI recognized, from the crude extract, three polypeptides with a molecular mass of 50, 68, and 30 kDa, respectively.These results provide a substantial basis for the further studies of the acid invertases in apple fruit.     

Invertase Proteinaceous Inhibitor of Cyphomandra Betacea Sendt Fruits

Abstract

This work describes a new invertase proteinaceous inhibitor from Cyphomandra hetacea Sendt. (tomate de árbol) 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.     

Alkaline β-fructofuranosidases of tuberous roots: Possible physiological function

Summary Alkaline invertase of roots of carrot (Daucus carota L.) did not hydrolyze raffinose while the acid invertase from the same tissue showed with this sugar ca. 60% of the activity found with sucrose. The activity of the two invertases was inhibited by fructose to a different extent, the K _i value being ca. 4×10^–2 M and 3×10^–1M, respectively, for the alkaline and the acid invertases from the roots of both carrot and turnip (Brassica rapa L.). It is proposed that fructose inhibition of acid invertase is of no physiological significance but that, in contrast, hexoses might regulate the activity of alkaline invertase.Comparing several species and cultivars, it was found that the content of reducing sugars and the activity of alkaline invertase of mature tuberous roots showed a positive correlation. This indicates that alkaline invertase may participate in the regulation of the hexose level of the cell, as was previously suggested for sugar-cane. A scheme is presented which proposes a way of participation of alkaline invertase in such a regulation, assuming that this enzyme is located in the cytoplasm and acid invertase is membrane-bound and mainly located at the cell surface.     

Invertases in Oat Seedlings: SEPARATION, PROPERTIES, AND CHANGES IN ACTIVITIES IN SEEDLING SEGMENTS

The soluble invertase activity in etiolated Avena seedlings was highest at the apex of the coleoptile and much lower in the primary leaf, mesocotyl, and root. The activity in all parts of the seedling consisted of two invertases (I and II) which were separated by chromatography on diethylaminoethylcellulose. Both enzymes appeared to be acid invertases, but they differed in molecular size, pH optimum, and the kinetic parameters K_m and V_max of their action on sucrose, raffinose, and stachyose. Invertase II had low stability at pH 3.5 and below, and exhibited high sensitivity to Hg²⁺, with complete inhibition by 2 micromolar HgCl₂. Segments of coleoptiles incubated in water lost about two-thirds of the total invertase activity after 16 hours. The loss of activity was due primarily to a decrease in the level of invertase II. The loss of invertase was decreased by indoleacetic acid, 2,4-dichlorophenoxyacetic acid, and α-naphthaleneacetic acid but not by β-naphthaleneacetic acid and p-chlorophenoxyisobutyric acid. Conditions that inhibited auxin-induced growth of the segments (20 millimolar CaCl₂ and 200 millimolar mannitol) also blocked the auxin effect on invertase loss.     

Purification and Some Properties of Cell Wall-bound Invertases from Sugar Beet Seedlings and Aged Slices of Mature Roots

Cell wall-bound invertases (EC 3.2.1.26) from both sugar beet seedlings and aged slices of mature roots were purified to homogeneity separately with CM-cellulose chromatography and Bio-Gel P-150 gel filtrations. The enzymes behaved similarly throughout the purification procedures. The purified enzymes are identical as characterized by specific activity, gel electrophoretic mobility, K_m for sucrose and raffinose (1.33 and 4.0 millimolar, respectively), mobility on Bio-Gel P-150 (molecular weight 28,000), optimum pH (4.6 to 5.0), optimum temperature, and dependence on NaCl concentration for insolubilization by DNA. The results suggest that the enzymes may be encoded for by the same structural gene.     

Studies on invertase from Mangifera indica

There are two types of invertase in mango tissues, one active at 0° and the other at 37°. These invertases have been partially purified and some of their properties studied.     

Diverse properties of external and internal forms of yeast invertase derived from the same gene

It has been shown by genetic analysis that the external and internal invertases from Saccharomyces cerevisiae share a common structural gene [Taussig, R., & Carlson, M. (1983) Nucleic Acids Res. 11, 1943-1954]. However, the only amino acid composition of these two forms of invertase reported to date has revealed extensive differences [Gascon, S., Neumann, N.P., & Lampen, J.O. (1968) J. Biol. Chem. 243, 1573-1577]. We have found from amino acid analyses of both enzymes and sodium dodecyl sulfate-polyacrylamide gel analysis of their cyanogen bromide peptides that they are most likely identical in their amino acid sequence. However, the invertases exhibit dramatically different physical properties, particularly in their stability. The most striking difference was in their renaturation following guanidine treatment where it was shown that inactivated external invertase could be renatured completely. Endo-beta-N-acetylglucosaminidase H treated external invertase was restored to 40% of its original activity while internal invertase remained completely inactive. The observed differences may be attributed to the presence and absence of the oligosaccharide moiety in the external and internal invertases, respectively.     

Invertase Activity in Normal and Mutant Maize Endosperms during Development

A bound invertase and two soluble invertases are found in the developing endosperm of maize (Zea mays L.). The two soluble invertases can be separated on diethylaminoethyl-cellulose and Sephadex columns and distinguished by their kinetic constants. One soluble invertase, invertase I, is present from the 10- to 28-day stages of endosperm development with maximal activity per normal endosperm at the 12-day stage. In two endosperm mutant lines, shrunken-1 and shrunken-2, there is a second increase in invertase I activity later in development which could be a secondary effect caused by the abnormal metabolism in these lines. Another soluble invertase, invertase II, is present in the embryo upon germination and is also found in the very young developing endosperm (6-day stage). The third form of invertase, bound invertase, is present in the endosperm by the 6-day stage, and its activity remains approximately constant during development.     

Natural diversity of potato (<Emphasis Type="Italic">Solanum tuberosum</Emphasis>) invertases

Background  

Invertases are ubiquitous enzymes that irreversibly cleave sucrose into fructose and glucose. Plant invertases play important roles in carbohydrate metabolism, plant development, and biotic and abiotic stress responses. In potato (Solanum tuberosum), invertases are involved in 'cold-induced sweetening' of tubers, an adaptive response to cold stress, which negatively affects the quality of potato chips and French fries. Linkage and association studies have identified quantitative trait loci (QTL) for tuber sugar content and chip quality that colocalize with three independent potato invertase loci, which together encode five invertase genes. The role of natural allelic variation of these genes in controlling the variation of tuber sugar content in different genotypes is unknown.     

Two Alkaline Phosphatases from a Butirosin A Producer Bacillus vitellinus

In low-phosphate medium, a butirosin A producer B. vitellinus produced two alkaline phosphatases. These enzymes were fractionated by DEAE-cellulose column chromatography. One phosphatase (Pho I) was eluted with the lower concentration of NaCl compared with the other phosphatase (Pho II). In the wild type strain, Pho I was completely repressed in the high-phosphate medium, but 30% of the fully-derepressed level of Pho II was still produced.

The phosphatase-negative mutant, P-15, that was shown to accumulate butirosin A-6′-N-diphosphate in our previous study, produced only one phosphatase (Pho I) under the low-phosphate condition. Therefore, P-15 was characteristic of the deficiency in Pho II synthesis.

The partially purified preparations of Pho I and II were characterized. Although both enzymes had a similar molecular weight, they could be differentiated in control of synthesis, heat stability, substrate specificity and other properties. Kinetic properties showed that Pho-II was more specific than Pho I to aminoglycoside-phosphates; butirosin A-3′-phosphate, butirosin A-6′-N-diphosphate and 6′-deamino-6′-hydroxybutirosin A-6′-O-diphosphate. The roles of the two phosphatases in butirosin A biosynthesis were discussed.     

Biochemical characterization and evaluation of invertases produced from Saccharomyces cerevisiae CAT-1 and Rhodotorula mucilaginosa for the production of fructooligosaccharides

Abstract

Invertases are used for several purposes; one among these is the production of fructooligosaccharides. The aim of this study was to biochemically characterize invertase from industrial Saccharomyces cerevisiae CAT-1 and Rhodotorula mucilaginosa isolated from Cerrado soil. The optimum pH and temperature were 4.0 and 70?°C for Rhodotorula mucilaginosa invertase and 4.5 and 50?°C for Saccharomyces cerevisiae invertase. The pH and thermal stability from 3.0 to 10.5 and 75?°C for R. mucilaginosa invertase, respectively. The pH and thermal stability for S. cerevisiae CAT-1 invertase from 3.0 to 7.0, and 50?°C, respectively. Both enzymes showed good catalytic activity with 10% of ethanol in reaction mixture. The hydrolysis by invertases occurs predominantly when sucrose concentrations are ≤5%. On the other hand, the increase in the concentration of sucrose to levels above 10% results in the highest transferase activity, reaching about 13.3?g/L of nystose by S. cerevisiae invertase and 12.6?g/L by R. mucilaginosa invertase. The results demonstrate the high structural stability of the enzyme produced by R. mucilaginosa, which is an extremely interesting feature that would enable the application of this enzyme in industrial processes.