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PubMed1983

[Trehalose-load test in gastroenterology].

In 35 infants trehalose-load-tests were carried out, biopsies of the intestinal mucosa of each patient were taken, and examined histologically. Furthermore, the enzyme activities of trehalase and lactase in each biopsy were determined. It was possible to demonstrate that morphology and function of the intestinal mucosa correlate differently depending on the severity of the mucosal damage. If there is only moderate mucosal damage, a rather weak correlation is seen either for the trehalose-load-test or for the disaccharidase activities with morphological changes. If damage was absent or severe, correlation improved. Both methods in comparison show a better correlation between trehalase activity and morphology than between trehalose-load-test and morphology. Furthermore, trehalase activity corroborated the histological findings better than lactase activity.

Adolescent↗
PubMed1994

Effects of newly developed solutions containing trehalose on twenty-hour canine lung preservation.

Trehalose is a nonreducing disaccharide that stabilizes the cell membrane under various stressful conditions. A previous study demonstrated that trehalose was effective in 12-hour canine lung preservation. We have developed new preservation solutions containing trehalose: an extracellular type ET-Kyoto solution (Na 100 mmol/L, K 44 mmol/L) and an intracellular type IT-Kyoto solution (Na 20 mmol/L, K 130 mmol/L). The composition of these solutions is identical except for the electrolyte content. We examined their efficacy in 20-hour lung preservation. Canine lungs were flushed with ET-Kyoto (group A, n = 6), with IT-Kyoto and prostaglandin E1 (25 micrograms/kg) (group B, n = 6), or with Euro-Collins solution and prostaglandin E1 (25 micrograms/kg) (group C, n = 7), and stored for 20 hours at 4 degrees C. Left lung transplantation was performed and evaluated for up to 130 minutes. The flush time was similar in the three groups. Arterial oxygen tensions (inspired oxygen fraction = 0.5) in group A were uniformly excellent (303.3 +/- 7.0 mm Hg 70 minutes after reperfusion and 303.0 +/- 19.6 mm Hg 130 minutes after reperfusion) and significantly higher than in group B (202.6 +/- 32.0 mm Hg, p < 0.05, and 197.8 +/- 44.0 mm Hg, p = 0.054, respectively) or group C (185.9 +/- 23.0 mm Hg, p < 0.01, and 155.7 +/- 36.3 mm Hg, p < 0.05, respectively). Peak inspiratory pressure in group A was significantly lower than in groups B and C (p < 0.05). Wet/dry weight ratio in group A was significantly lower than in groups B (p < 0.05) and C (p < 0.01). Histologic and scanning electron microscopic examinations showed better preservation in group A than in groups B and C. We conclude that ET-Kyoto is superior to IT-Kyoto and to Euro-Collins solution for 20-hour lung preservation.

Animals↗
PubMedDate not supplied

Uptake and use of the osmoprotective compounds trehalose, glucosylglycerol, and sucrose by the cyanobacterium Synechocystis sp. PCC6803.

Accumulation of exogenously supplied osmoprotective compounds was analyzed in the cyanobacterium Synechocystis sp. PCC6803, which synthesizes glucosylglycerol as the principal osmoprotective compound. Glucosylglycerol and trehalose were accumulated to high levels and protected cells of a mutant unable to synthesize glucosylglycerol against the deleterious effects of salt stress. In the wild-type, uptake of trehalose repressed the synthesis of glucosylglycerol and caused metabolic conversion of originally accumulated glucosylglycerol. Trehalose cannot be synthesized by Synechocystis and was not or only insignificantly metabolized. Sucrose, which can be synthesized in low quantities by Synechocystis, was also taken up, as indicated by its disappearance from the medium. Sucrose was not accumulated to high levels, probably due to a sucrose-degrading activity found in cells adapted to both low- and high-salt conditions. Despite its low intracellular concentration, sucrose showed a weak osmoprotective effect in salt-shocked cells of a mutant unable to synthesize glucosylglycerol.

Cyanobacteria↗
PubMed1979

Intralesional immunotherapy of malignant melanoma with mycobacterium smegmatis cell wall skeleton combined with trehalose dimycolate (P3).

The clinical efficacy of intralesional immunotherapy utilizing Mycobacterium smegmatis cell wall skeleton (CWS) and trehalose dimycolate attached to oil droplets was investigated in 15 patients with advanced malignant melanoma. Patients received 300 microgram to 1050 microgram of the CWS combined with one-half that amount of trehalose dimycolate every 1 to 2 weeks for a total of 8 treatments. Therapy was continued if regression of injected lesions only occurred. Therapy was discontinued if regression of noninjected disease also occurred. Six of the 15 patients had regression of at least one injected lesion. Four of these 6 patients also had regression of noninjected disease lasting 4+, 6, 16 and 18+ months. Response was highly related to immune status. Six (83%) of 7 patients who reacted to one of a battery of skin tests responded. All 8 patients who did not react to skin tests failed to respond to therapy. There was no correlation of response with sex, prior therapy, disease-free interval or presence of visceral disease. Mycobacterial CWS and trehalose dimycolate is an effective immunotherapeutic agent. Additional studies of purified immunoadjuvants are warranted.

Cell Wall↗
PubMed1996

Inhibition of the trehalose-P synthase of mycobacteria by various antibiotics.

A number of antibiotics were tested as potential inhibitors of the purified trehalose-P synthase of Mycobacterium smegmatis. Of about 30 compounds tested, 4 (cathomycin, circulin, diumycin, and moenomycin) were active against this enzyme. Thus each of these compounds inhibited the formation of trehalose-P by the purified trehalose-P synthase when either UDP-glucose or GDP-glucose was used as the glucosyl donor. However, preincubation of the synthase with heparin, a polyanion activator of the enzyme when UDP-glucose is used as the substrate, prevented the inhibition by these various antibiotics. Fifty percent inhibition by diumycin and moenomycin occurred at a concentration of about 50 microg/ml (Ki of about 1 x 10(-5) M), but 50% inhibition by cathomycin and circulin required substantially higher concentrations (about 50 to 200 microg/ml). The inhibition by cathomycin, diumycin, and moenomycin was of the competitive type, whereas that by circulin was noncompetitive in nature. However, the inhibition was of a complex nature and the data suggest two different binding sites for these inhibitors. Photoaffinity labeling of the synthase with an azido-UDP-[32P]glucose probe was effectively blocked by diumycin, moenomycin, or cathomycin indicating that these inhibitors do interact at the substrate binding site. These antibiotics also inhibited the growth of M. smegmatis when added to cells innoculated into trypticase soy broth. The inhibition of growth was concentration-dependent and directly proportional to the size of the bacterial innoculum. These antibiotics, however, did not inhibit protein synthesis nor did they inhibit the incorporation of mannose into lipid-linked saccharides.

Anti-Bacterial Agents↗
PubMed1991

Chemical synthesis and biological activities of 6,6'-di-O-mycoloyl-beta,beta- and -alpha,beta-trehalose.

6,6'Di-O-mycoloyl-beta,beta-trehalose (beta,beta-TDM) and 6,6'-di-O-mycoloyl-alpha,beta-trehalose (alpha,beta-TDM) were synthesized and their toxicity and ability to activate peritoneal macrophages in situ were examined in mice, in comparison with 6,6'-di-O-mycoloyl-alpha,alpha-trehalose (TDM). Both beta,beta-TDM and alpha,beta-TDM caused a decrease in body weight two days after injection, however the weights reverted to a normal level. No deaths were caused by either analog. On the other hand, TDM showed potent toxicity, causing decrease in body weight and death of all animals injected. Beta,beta-TDM and alpha,beta-TDM were effective in the in situ activation of mouse peritoneal macrophages.

Animals↗
PubMed1984

The pathogenesis of trehalose dimycolate-induced interstitial pneumonitis. III. Evidence for a role for T lymphocytes.

Trehalose dimycolate, a glycolipid component of the cell walls of mycobacteria, induces interstitial pneumonitis and alveolar hemorrhages in C57BL/6 and C57BL/10 mice. Homozygous nude (nu/nu) mice of these backgrounds are not susceptible to this form of pulmonary injury. However, after administration of T-lymphocyte-enriched spleen cell preparations from syngeneic donors, homozygous nude mice become susceptible to trehalose dimycolate. The observations suggest that production of pulmonary lesions by this mycobacterial component is dependent on T lymphocytes. While the mechanisms are still under study, we propose that trehalose dimycolate can function as an activator of T lymphocytes and that products of activated T cells are responsible for production of the pulmonary lesions.

Animals↗
PubMed1988

Biomedical applications of chromatographic fraction containing trehalose dimycolate in squalane emulsion.

Trehalose dimycolate extracted from mycobacteria is a potent immunomodulator. Incorporation of trehalose dimycolate in a squalane-in-water emulsion leads predominantly to the formation of vesicular structures, which are observable by electron microscopy. The interaction between vesicles of trehalose dimycolate and the immunocompetent cells results in an enhancement of the host defence mechanisms and induction of non-specific resistance against viral, parasitic, and bacterial pathogens and certain tumors. A brief review of the pertinent observations is presented.

Adjuvants, Immunologic↗
PubMed1998

Trehalose-6P synthase is essential for trehalase activation triggered by glucose, nitrogen source or heat shock, but not by osmostress, in Schizosaccharomyces pombe.

Cells of Schizosaccharomyces pombe disrupted in the tps1+ gene, which encodes trehalose-6P synthase, were unable to increase trehalase activity in response to the addition of glucose or nitrogen source. Moreover, in contrast to normal cells, Deltatps1 cells did not increase trehalase activity by heat shock. Overexpression of tps1+ in cells devoid of trehalose-6P synthase restored the ability to increase trehalase after addition of nutrients or by heat shock. In glucose-repressed cells, which are normally refractory to the activation of trehalase by glucose, overexpression of tps1+ enabled the cells to increase trehalase activity upon addition of the sugar. Northern hybridisations were used to determine the level of mRNA for trehalase in normal and Deltatps1 cells. Transcription for trehalase was not significantly altered upon addition of glucose or nitrogen source, but increased markedly in heat-shocked cells even though trehalase activity remained unchanged in Deltatps1 cells. These findings provide evidence for a role of trehalose-6P synthase in the signalling pathway causing post-transcriptional activation of neutral trehalase induced by nutrients or heat shock. However, trehalase increased in Deltatps1 cells under hypertonic conditions suggesting the existence in Schiz. pombe of a distinct regulatory mechanism for enhancement of trehalase, specifically triggered by osmostress.

Enzyme Activation↗
PubMed1995

Trehalose synthase: guard to the gate of glycolysis in yeast?

The addition of glucose to cells of the yeast Saccharomyces cerevisiae triggers a variety of regulatory phenomena. Initial glucose metabolism is required for the induction of most of them. Mutants deficient in both glucose-induced signalling and the control of initial glucose metabolism have a defect in the trehalose-6-phosphate synthase catalytic subunit of the trehalose synthase complex. This finding has raised novel questions about the control of glucose influx into glycolysis in yeast and its connection to the glucose-sensing mechanism. This dual function of the trehalose-6-phosphate synthase subunit has been found in several yeast species, suggesting that this control system might be widespread in fungi and possibly also in other organisms.

Glucosyltransferases↗
PubMed1999

Trehalose metabolism in plants.

It has long been thought that the biosynthesis of trehalose, a sugar present in all kingdoms, is absent from the vast majority of higher plants. However, recent experiments have indicated that genes from Arabidopsis are able to complement yeast strains deficient in trehalose metabolism. In yeast, trehalose has been suggested as a regulatory component in the control of glycolytic flux and in a variety of stress survival strategies. Thus, the occurrence of complimentary genes in Arabidopsis and yeast might lead to the development of strategies and applications for improvement of crop plants.

Journal Article↗
PubMed2006

Gene cloning, expression, and biochemical characterization of a recombinant trehalose synthase from Picrophilus torridus in Escherichia coli.

A trehalose synthase (TSase) gene from a hyperacidophilic, thermophilic archaea, Picrophilus torridus, was synthesized using overlap extension PCR and transformed into Escherichia coli for expression. The purified recombinant P. torridus TSase (PTTS) showed an optimum pH and temperature of 6.0 and 45 degrees C, respectively, and the enzyme maintained high activity at pH 5.0 and 60 degrees C. Kinetic analysis showed that the enzyme has a 2.5-fold higher catalytic efficiency (k(cat)/K(M)) for maltose than for trehalose, indicating maltose as the preferred substrate. The maximum conversion rate of maltose into trehalose by the enzyme was independent of the substrate concentration, tended to increase at lower temperatures, and reached approximately 71% at 20 degrees C. Enzyme activity was inhibited by Hg2+, Al3+, and SDS. Five amino acid residues that are important for alpha-amylase family enzyme catalysis were shown to be conserved in PTTS (Asp203, Glu245, Asp311, His106, and His310) and required for its activity, suggesting this enzyme might employ a similar hydrolysis mechanism.

Amino Acid Sequence↗
PubMed2004

Gts1p stabilizes oscillations in energy metabolism by activating the transcription of TPS1 encoding trehalose-6-phosphate synthase 1 in the yeast Saccharomyces cerevisiae.

We reported previously that Gts1p regulates oscillations of heat resistance in concert with those of energy metabolism in continuous cultures of the yeast Saccharomyces cerevisiae by inducing fluctuations in the levels of trehalose, but not in those of Hsp104 (heat shock protein 104). Further, the expression of TPS1, encoding trehalose-6-phosphate synthase 1, and HSP104 was activated by Gts1p in combination with Snf1 kinase, a transcriptional activator of glucose-repressible genes, in batch cultures under derepressed conditions. Here we show that, in continuous cultures, the mRNA level of TPS1 increased 6-fold in the early respiro-fermentative phase, while that of HSP104 did not change. The expression of SUC2, a representative glucose-repressible gene encoding invertase, also fluctuated, suggesting the involvement of the Snf1 kinase in the periodic activation of these genes. However, this possibility was proven to be unlikely, since the oscillations in both TPS1 and SUC2 mRNA expression were reduced by approx. 3-fold during the transient oscillation in gts1Delta (GTS1-deleted) cells, in which the energy state determined by extracellular glucose and intracellular adenine nucleotide levels was comparable with that in wild-type cells. Furthermore, neither the mRNA level nor the phosphorylation status of Snf1p changed significantly during the oscillation. Thus we suggest that Gts1p plays a major role in the oscillatory expression of TPS1 and SUC2 in continuous cultures of Saccharomyces cerevisiae, and hypothesized that Gts1p stabilizes oscillations in energy metabolism by activating trehalose synthesis to facilitate glycolysis at the shift from the respiratory to the respiro-fermentative phase.

Adenine Nucleotides↗
PubMed2005

The role of trehalose-6-phosphate synthase in Arabidopsis embryo development.

We previously showed that trehalose-6-phosphate synthase 1 (TPS1), which catalyses the first step in trehalose synthesis, is essential for embryo maturation in Arabidopsis. The tps1 mutant embryos develop more slowly than wild type. Patterning in the tps1 embryos appears normal but they do not progress past the torpedo stage to cotyledon stage, which is when storage reserves start to accumulate in the expanding cotyledons. Our initial data led to the hypothesis that trehalose metabolism plays a key role in regulating storage reserve accumulation by allowing the embryo to respond to the dramatic increase in sucrose levels that occurs at the torpedo stage of embryo development. More recent data demonstrate that while the tps1 mutant is blocked in the developmental progression of embryos from torpedo to cotyledon stage the expression of genes involved in the accumulation of storage reserves proceeds in a similar fashion to wild type. Thus it appears that induction of metabolic processes required for accumulation of storage reserves in tps1 occurs independently of the developmental stage and instead follows a temporal programme similar to wild-type seeds in the same silique.

Arabidopsis↗
PubMed1996

Trehalose-P synthase of mycobacteria: its substrate specificity is affected by polyanions.

The trehalose-P synthase was purified to near homogeneity from the cytoplasmic fraction of Mycobacterium smegmatis. At the final stage of purification, the enzyme preparation showed one major band of 59 kDa on SDS gels. The 59 kDa band became labeled with N3-UDP[32P]-glucose, and this labeling was inhibited in a concentration-dependent manner by either unlabeled UDP-glucose or GDP-glucose. The native enzyme also had a molecular weight of about 60 kDa by gel filtration, indicating that the active enzyme is a monomer. The 59 kDa protein was subjected to endoproteinase Lys-C digestion, and three peptides isolated by HPLC were sequenced. The sequences of 56 amino acids in these three peptides showed 60% identity to the trehalose-P synthases of Saccharomyces cerevesiae and Schizosaccharomyces pombe. The purified mycobacterial enzyme catalyzed the synthesis of trehalose-P from glucose-6-P and a variety of nucleoside diphosphate glucose derivatives, depending on whether a polyanion was absent or present. Thus, UDP-glucose and GDP-glucose were the best glucosyl donors, but maximum activity with UDP-glucose required the presence of a polyanion such as heparin, whereas activity with GDP-glucose was relatively independent of polyanion. The presence of heparin in the incubation mixture increased the affinity of the enzyme for UDP-glucose by a factor of 100, or more. However, the affinity for GDP-glucose was only twofold better in the presence of heparin. The purified synthase also utilized ADP-glucose and CDP-glucose, but the K(m) for these glucosyl donors was quite high even in the presence of polyanion. The effect of heparin on UDP-glucose activity was dose-dependent and maximum at about 1-2 micrograms of heparin/incubation. However, the size of the heparin molecule (i.e., the number of monosaccharide residues) was critical for activation, and only those heparins with 18 or more monosaccharide units were effective in stimulating activity.

Chromatography, Gel↗
PubMed2004

The Arabidopsis trehalose-6-P synthase AtTPS1 gene is a regulator of glucose, abscisic acid, and stress signaling.

In Arabidopsis (Arabidopsis thaliana), trehalose is present at almost undetectable levels, excluding its role as an osmoprotectant. Here, we report that overexpression of AtTPS1 in Arabidopsis using the 35S promoter led to a small increase in trehalose and trehalose-6-P levels. In spite of this, transgenic plants displayed a dehydration tolerance phenotype without any visible morphological alterations, except for delayed flowering. Moreover, seedlings overexpressing AtTPS1 exhibited glucose (Glc)- and abscisic acid (ABA)-insensitive phenotypes. Transgenic seedlings germinated on Glc were visibly larger with green well-expanded cotyledonary leaves and fully developed roots, in contrast with wild-type seedlings showing growth retardation and absence of photosynthetic tissue. An ABA dose-response experiment revealed a higher germination rate for transgenic plants overexpressing AtTPS1 showing insensitive germination kinetics at 2.5 mum ABA. Interestingly, germination in the presence of Glc did not trigger an increase in ABA content in plants overexpressing AtTPS1. Expression analysis by quantitative reverse transcription-PCR in transgenic plants showed up-regulation of the ABI4 and CAB1 genes. In the presence of Glc, CAB1 expression remained high, whereas ABI4, HXK1, and ApL3 levels were down-regulated in the AtTPS1-overexpressing lines. Analysis of AtTPS1 expression in HXK1-antisense or HXK1-sense transgenic lines suggests the possible involvement of AtTPS1 in the hexokinase-dependent Glc-signaling pathway. These data strongly suggest that AtTPS1 has a pivotal role in the regulation of Glc and ABA signaling during vegetative development.

Abscisic Acid↗
PubMed1985

C Nuclear Magnetic Resonance Study of Mannitol Cycle and Trehalose Synthesis during Glucose Utilization by the Ectomycorrhizal Ascomycete Cenococcum graniforme.

(13)C nuclear magnetic resonance spectroscopy has been used to follow the utilization of glucose for the synthesis of carbohydrates in the ectomycorrhizal ascomycete Cenococcum graniforme. The fate of (13)C label was analyzed in vivo and in mycelial extracts. The major carbohydrates produced from [1-(13)C]glucose and [6-(13)C]glucose were mannitol and trehalose. Mannitol was mainly synthesized via a direct route from glucose. Scrambling of the (13)C label was observed to occur in trehalose during glycolysis. From the analysis of the scrambling patterns, it is concluded that the mannitol cycle was operative and that a large part of the carbon of glucose was used to form trehalose after cycling through the mannitol pool. The activities of NAD-mannitol-l-P dehydrogenase (EC 1.1.1.17) and NADP-mannitol dehydrogenase (EC 1.1.1.138), which participate in the mannitol cycle relative to the activity of glycolytic enzymes, provide evidence that the cycle is important for NADPH production.

Journal Article↗
PubMed2002

Characterization of Escherichia coli OtsA, a trehalose-6-phosphate synthase from glycosyltransferase family 20.

The Ots gene cluster of Escherichia coli encodes the synthetic apparatus for the formation of alpha,alpha-1,1-trehalose, a non-reducing glucose disaccharide. The otsA gene encodes a trehalose-6-phosphate synthase, a glycosyltransferase which catalyses the synthesis of alpha,alpha-1,1-trehalose-6-phosphate from glucose-6-phosphate using a UDP-glucose donor. It has been classified into glycosyltransferase family GT-20 based upon amino-acid sequence similarities. The otsA gene has been cloned and recombinant protein overexpressed using a pET-based system in E. coli BL21 cells. The recombinant protein (MW approximately 54.7 kDa) is active and has been crystallized in two forms suitable for X-ray diffraction analysis. The first is orthorhombic, P2(1)2(1)2(1), with unit-cell parameters a = 104.1, b = 127.8, c = 179.9 A. Data for this form have been collected to 3.0 A resolution at the CLRC Daresbury Synchrotron Radiation Source. The second form has unit-cell parameters a = b = 141.9, c = 317.8 A and displays the apparent space group P4(2). These crystals diffract beyond 2 A resolution, but display merohedral twinning.

Cloning, Molecular↗