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Purification and some properties of a trehalase from a green alga, Lobosphaera sp.

An unicellular green alga identified as Lobosphaera sp. by morphological observations was selected as a source of trehalase. The alga grew well heterotrophically and produced intracellular trehalase using Polypepton, yeast extract, and glycerol as nutrients. The enzyme was highly purified by ammonium sulfate fractionation, column chromatography on DEAE-Toyopearl, Sepharose CL-4B, and SP-Toyopearl. The molecular mass was estimated to be 400 kDa by gel filtration. SDS-PAGE indicated that the enzyme consisted of two subunits with a molecular mass range of 180-220 kDa and it contained carbohydrates. The enzyme was most active at pH 5.5 and at 65 degrees C and stable between pH 4-9 and below 65 degrees C. Fe3+ inactivated the enzyme. Sucrose was a competitive inhibitor with a Ki of 7.5 mM. The enzyme specifically hydrolyzed trehalase with a Km of 0.6 mM.

Carbohydrate Metabolism↗

Soluble and particle-bound trehalase in the silk glands during larval-pupal development of the silkworm, Bombyx mori.

Trehalase localization in silk glands of the silkworm, Bombyx mori has been studied during larval-pupal development. Subcellular distribution of the silk gland trehalase depends upon larval-pupal development. The activity increases in the soluble fraction with a concomitant decrease in the particle-bound fraction during larval-pupal development. The pH-optimum value of trehalase activity in the particle-bound fraction changes from 6.5 to 6.0, and in the soluble fraction from 5.5 to 4.5 in the course of the silk gland degeneration during metamorphosis.

Animals↗

[Influence of parenterally injected trehalose in mammals having trehalase activity at different sites].

When trehalose is injected via parenteral pathway into animals lacking kidney trehalase (rat), more than 75 per cent of this disaccharide is eliminated in urine. When the injected animals possess an active kidney trehalase (guinea-pig, rabbit), there is only a low urinary trehalose excretion. Moreover, in rabbit, a marked hyperglycaemia is observed which is due to the rapid hydrolysis of trehalose by kidney trehalase.

Animals↗

Trehalase activity and its regulation during growth of Saccharomyces cerevisiae.

Trehalase activity decreased in 95% at the onset of the transition phase of growth of S. cerevisiae. The question which we raised was whether this phenomenon was due to proteolysis or to conversion of the enzyme to a less active form (dephosphorylation). Immunological methods allowed to identify the presence of the trehalase protein during cell growth. At the same stage of growth, an increase in the non-phosphorylated enzyme was detected "in vitro". Results utilizing mutant strains also indicated that regulation occurred by interconversion of forms. The same mechanism also seems to control trehalase activity in non proliferating conditions.

Blotting, Western↗

[Urinary trehalase activity during normal pregnancy: tubular dysfunctions].

By measuring urinary trehalase which is localized in renal brush borders, we examined whether tubular dysfunction occurred or not during and after normal pregnancy. Urinary trehalase activity in 1st trimester, 2nd trimester, and 3rd trimester was increased significantly as compared with the controls (=non-pregnant women) (p less than 0.01). After delivery, urinary trehalase activity in puerperal 5th day was decreased to the level of the 1st trimester, and the activity of puerperal on the 30th day was in the range of the control value. Urinary beta 2-microglobulin (beta 2-MG) in the 1st trimester and 2nd trimester was not increased significantly as compared with the controls. Urinary beta 2-MG in the 3rd trimester, however, was significantly higher than that in the controls. After delivery, the value for beta 2-MG in puerperal on the 5th day was not decreased significantly as compared with the 3rd trimester, and in puerperal on the 30th day, urinary beta 2-MG was decreased to the control value. Urinary N-acetyl-beta-D-glucosaminidase (NAG) in the 3rd trimester was significantly higher than that in the controls (p less than 0.01) and in the 1st trimester (p less than 0.02). After delivery, a significant decrease was observed in urinary NAG between 5th puerperal day and the 3rd trimester. Moreover, urinary NAG on the 30th puerperal day was the level of the controls. On the basis of these results, it is inferred that tubular dysfunction is observed during normal pregnancy.

Female↗

A study of trehalase (EC 3.2.1.28) and trehalose in relation to aging in Callosobruchus analis.

Trehalase (EC. 3.2.1.28) activity has been studied during aging in male and female Callosobruchus analis beetles. Enzyme activity was much higher in females than males throughout adult life. Trehalase showed two peaks of activity in females, a small peak on the 3rd day and another on the 10th day after adult ecdysis, while males showed one peak only on the 10th day after emergence. Besides trehalase activity, trehalose as a percentage of total sugars, and mortality curves have been studied. It was found that the energy needs of the insects also increase as they age.

Aging↗

Trehalase activity in diabetes mellitus and in cirrhosis of the liver.

Trehalase (an enzyme decomposing the disaccharide trehalose) activity was studied in 29 healthy subjects, 25 patients with cirrhosis and 112 diabetics. Mean trehalase activity was 176 +/- 11 units in the control group, 647 +/- 421 units in the patients with cirrhosis and 467 +/- 239 units in diabetics. The differences between the control group on the one hand and the groups with cirrhosis and diabetes on the other were statistically significant. The results show that the organism, under pathological conditions, makes far greater use of its enzymatic apparatus to assure its basic requirements, but the scatter of the values is so great that the determination of trehalase has no discriminative value in individual cases.

Aged↗

[Influence of parenteral injection of trehalose on mammals with different trehalase levels].

Administration of trehalose by parenteral route to mammals (Guinea-pig and rabbit) equipped with Kidney trehalase is followed by rapid hydrolysis of the disaccharide which is excreted in urine only in very low amounts. When the animal under investigation has not trehalase in the kidney (rat), practically the total amount of trehalase is excreted in urine. Perfusion of kidney in rabbit confirms the very rapid hydrolysis of trehalose by this organ.

Animals↗

Molecular activation of a trehalase purified from the fat body of a coleopteran insect (Tenebrio molitor), by an endogenous insulin-like peptide.

Trehalase is the major factor involved in the release of glucose in the various insects organs. During physiological regulatory processes, and particularly during the induction or breaking of diapause, insulin-like factors are involved. Then, by contrast with the classical hypoglycemic role of insulin, the insulin-like peptide isolated from the insect (brain and/or fat body) is also able to activate the fat body trehalase in vitro, through a direct molecular interaction. The mechanism involves the binding of the activator to the "trehalase-trehalose complex", rather than on the free enzyme, without change in the Hill coefficient nor in the maximum velocity (Vmax). The rate constant KR is conversely proportional to the activator concentration. This mechanism can be totally quenched by adding an anti-serum anti-insulin-like factor in the reaction medium.

Animals↗

Urinary trehalase activity and renal brush-border damage in inhabitants of a cadmium-polluted area (Jinzu River basin).

Elevated urinary trehalase activity was observed in the inhabitants of the Jinzu River basin. Urinary trehalase activity was correlated with other urinalysis components, such as beta 2-microglobulin, glucose, amino nitrogen, and cadmium, of which a high level was observed in cadmium-polluted areas as compared with the reference area. Renal trehalase is specifically localized in tubular brush borders [M. Nakano, J. Histochem. Cytochem., 30 (1982) 1243-1248]. From these results it is inferred that tubular brush-border damage occurs in inhabitants of the Jinzu River basin.

Aged↗

Trehalase: a new pollen enzyme.

Pollen from 5 plant species (Lycopersicon pimpinellifolium Mill., Hermerocallis minor Mill., Galtonia condicans Decne., Camellia japonica L., and Lathyrus odoratus L.) representing 4 families germinated well in media containing trehalose as the sole carbon source. Data are presented indicating that pollen metabolized this disaccharide for germination and subsequent pollen-tube growth; the sugar was not merely an osmoregulator. An inhibitor of trehalase activity depressed germination in trehalose but not in sucrose. Phloridzin dihydrate, an inhibitor of glucose transport, depressed germination in both disaccharides. Biochemical tests demonstrated that a pollen extract was capable of hydrolyzing trehalose to its constituent glucose monomers. Heat inactivation experiments confirmed the presence of a distinct trehalase having a rigid specificity for its substrate. By this method, trehalase activity was completely distinguishable from the activities of other alpha- and beta-glucosidases and beta-galactosidases. Localization data indicated that the enzyme diffused from intact grains and was probably soluble. The presence of its substrate could not be demonstrated in pollen or in stigmatic or stylar tissues.

Glycoside Hydrolases↗

Synthesis, inhibition properties, and theoretical study of the new nanomolar trehalase inhibitor 1-thiatrehazolin: towards a structural understanding of trehazolin inhibition.

A new trehazolin analogue, 1-thiatrehazolin, has been synthesized from carbohydrate precursors by a highly efficient route based on our previously developed ketone/oxime ether reductive carbocyclization reaction for the construction of the cyclitol ring and an intramolecular nucleophilic displacement reaction for the construction of the thiazoline ring. 1-Thiatrehazolin is a very potent, slow, tight-binding trehalase inhibitor. A structural model for trehalase inhibition by trehazolin and its analogues, based on the experimental results and supported by theoretical calculations, is proposed.

Animals↗

Trehalases from spores and vegetative cells of yeast Saccharomyces cerevisiae.

Trehalase (THA) activity from S. cerevisiae spores and vegetative cells could be differentiated in cell-free extracts. THA from the vegetative cells has an optimal activity at neutral pH whereas biphase pH optimum in the spores was observed. The enzyme from the spores exhibited higher thermostability than that from the vegetative cells. The presence of magnesium ions was necessary mainly for THA activity from the vegetative cells. The effect of the other metal ions studied: Hg2+, Ag2+, Cu2+, Fe3+, Ni2+, Cd2+ etc. (Table II), on THA from both sources was almost the same, however, the spores THA was resistant to Pb2+ and especially to Zn2+. Moreover, the influence of inorganic polyphosphates and polyamines was also quite dissimilar. Polyphosphates inhibited THA from the vegetative cells and to a smaller extent from the spores. On the other hand, polyamines stimulated highly THA activity from vegetative yeast cells in contrast to spores one. The effect of these ions modulators would facilitate differentiating of THA activity in the cell-free extracts from both sources. These data could be interpreted as phenotypic reflections of trehalase genes expression in the S. cerevisiae cells.

Culture Media↗

Differential extraction of N-acetylglucosaminidase and trehalase from the cell envelope of Candida albicans.

Dithiothreitol (DTT) extraction of N-acetylglucosaminidase and trehalase from intact Candida albicans ATCC 10261 cells was monitored as an index of cell envelope porosity during N-acetylglucosamine-induced morphogenesis. Trehalase, which is secreted into the cell envelope during starvation and bud-formation, displayed similar extraction kinetics in starved, germ tube-forming, and bud-forming cells, indicating that the mother cell wall remains largely unchanged during morphogenic outgrowth and that the porosity of bud and mother cell walls is similar. N-acetylglucosaminidase, which is secreted specifically during morphogenesis, was released eightfold more rapidly from germ tube-forming than bud-forming cells, reflecting major differences in porosity between bud and germ tube. In addition, by assaying DTT extracts and extracted cell residues, it was found that the total extracellular N-acetylglucosaminidase activity increased 2- to 2.5-fold during DTT treatment. Thus, DTT unmasks a cryptic form of N-acetylglucosaminidase. The cryptic activity was associated with the cell wall fraction.

Acetylglucosaminidase↗

Genetic and biochemical aspects of trehalase from Drosophila melanogaster.

Only one molecular form of trehalase (E.C. 3.2.1.28) was detectable in adult Drosophila melanogaster by polyacrylamide gel electrophoresis and isoelectric focusing. An examination of duplication- and deletion-bearing aneuploids exhibiting dosage sensitivity indicated that the enzyme is encoded by a gene, Treh+, located between 55B and 55E of the second chromosome. The tissue-specific soluble and particulate forms of trehalase appear to be manifestations of a single protein encoded by a single gene.

Aneuploidy↗

Antisense-mediated inhibition of acid trehalase (ATH1) gene expression promotes ethanol fermentation and tolerance in Saccharomyces cerevisiae.

Acid trehalase gene (ATH1) expression was decreased using the antisense-RNA technique in Saccharomyces cerevisiae. The 500 bp DNA fragments containing anti-ATH1 gene between +1 and +500 were amplified using PCR and fused to yeast ADH1, CYC1 and ATH1 promoters. Yeast cells harboring the recombinant plasmids had a low activity of acid trehalase and promoted ethanol fermentation compared to the control yeast cells harboring the vector plasmid only. The recombinant yeast had a high viability with 8% (v/v) ethanol.

Cell Division↗

Physical properties and Tris inhibition of an insect trehalase and a thermodynamic approach to the nature of its active site.

The midgut from Rhynchosciara americana larvae display a trehalase (alpha,alpha'-trehalose glucohydrolase, EC 3.2.1.28) which is soluble with a molecular weight of 122 000 and pI 4.6. The optimum pH of the enzyme is 6.0, its apparent Km for trehalose is 0.67 mM and its energy of activation is 16.7 kcal/mol. Sulfhydryl reagents do not inhibit the trehalase. The results suggest the existence of two carboxyl groups in the active site, one of which has a very high (8.3) pK. The increase of the pK values of the essential groups of the free enzyme in the presence of increasing concentrations of dioxane supports the hypothesis that these groups are carboxyls. The purified enzyme hydrolyzes only alpha,alpha'-trehalose and it is competitively inhibited by several compounds.

Animals↗

Anomeric specificity of glucose effect on cAMP, fructose 1,6-bisphosphatase, and trehalase in yeast.

The addition of beta-D-glucose (final concentration, 50 mM) to a cell suspension of Saccharomyces cerevisiae in stationary phase caused a rapid 4-fold increase in the concentration of cAMP, while a 2-fold increase of cAMP was observed by the addition of alpha-D-glucose. beta -D-Glucose was also more effective than alpha-D-glucose in the inactivation of fructose 1,6-bisphosphatase and the activation of trehalase. These results, taken together with the previous report that alpha-D-glucose is transported more rapidly than beta-D-glucose in Saccharomyces cerevisiae, do not support the view currently proposed by some investigators that cotransport of D-glucose with protons causes the depolarization of the cell membrane, resulting in the activation of adenylate cyclase. The present data, however, provides supporting evidence for the view that cAMP-dependent protein kinase is implicated in the inactivation of fructose 1,6-bisphosphatase and the activation of trehalase.

Cyclic AMP↗