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PubMed1996

Purification and characterization of new trehalose-producing enzymes isolated from the hyperthermophilic archae, Sulfolobus solfataricus KM1.

Amylolytic activity that converts soluble starch to alpha, alpha-trehalose (trehalose), was found in the cell homogenate of the hyperthermophilic acidophilic archae, Sulfolobus solfataricus KM1. DEAE chromatography of the homogenate as well as other new reliable assay methods showed two enzymes to be essential for this activity. These enzymes, a glycosyltransferase and an amylase, were purified to homogeneity and characterized. Their molecular masses were 76 kDa and 61 kDa and activities were maximal at 70-80 degrees C and 70-85 degrees C, respectively. High thermostability was noted for each. The reaction products by the two enzymes on maltooligosaccharides were identified by 1H- and 13C-NMR spectra and HPLC analysis. The cooperative mechanism of the two enzymes was used in a new enzymatic pathway for trehalose synthesis from starch.

Amylases↗
PubMed1996

Cloning and sequencing of trehalose biosynthesis genes from Rhizobium sp. M-11.

The two genes encoding maltooligosyl trehalose synthase and maltooligosyl trehalose trehalohydrolase, which are related to biosynthesis of alpha, alpha-trehalose, were cloned from Rhizobium sp. M-11. Sequence analysis showed that the synthase gene composed of 2316 bp was connected with the hydrolase gene of 1788 bp by an overlap of one nucleotide. The deduced amino acid sequences of both enzymes have several regions common to amylolytic enzymes belonging to an "alpha-amylase family".

Amino Acid Sequence↗
PubMed1997

Synthesis of glycosyl-trehaloses by cyclomaltodextrin glucanotransferase through the transglycosylation reaction.

Cyclomaltodextrin glucanotransferase from Bacillus stearothermophilus produced a series of glycosyl-trehaloses through the transglycosylation reaction with cyclomaltohexaose as the glycosyl donor and trehalose as its acceptor. After beta-amylase treatment, five species of glycosyl-trehaloses were isolated by column chromatography. After chemical and enzymatic analyses, it was concluded that these oligosaccharides were alpha-maltosyl alpha-D-glucopyranoside, alpha-maltotriosyl alpha-D-glucopyranoside, alpha-maltosyl alpha-maltoside, alpha-maltotriosyl alpha-maltoside, and alpha-maltotriosyl alpha-maltotrioside. These were not hydrolyzed by salivary amylase, artificial gastric juice, or pancreatic amylase, however they were hydrolyzed by enzymes of the small intestine.

Carbohydrate Sequence↗
PubMed2005

A molecular dynamics study of the response of lipid bilayers and monolayers to trehalose.

Surface tensions evaluated from molecular dynamics simulations of fully hydrated dipalmitoylphosphatidylcholine bilayers and monolayers at surface areas/lipid of 54, 64, and 80 A2 are uniformly lowered 4-8 dyn/cm upon addition of trehalose in a 1:2 trehalose/lipid ratio. Constant surface tension simulations of bilayers yield the complementary result: an increase in surface area consistent with the surface pressure-surface area (pi-A) isotherms. Hydrogen bonding by trehalose, replacement of waters in the headgroup region, and modulation of the dipole potential are all similar in bilayers and monolayers at the same surface area. These results strongly support the assumption that experimental measurements on the interactions of surface active components such as trehalose with monolayers can yield quantitative insight to their effects on bilayers. The simulations also indicate that the 20-30 dyn/cm difference in surface tension of the bilayer leaflet and monolayer arises from differences in the chain regions, not the headgroup/water interfaces.

Computer Simulation↗
PubMed2005

Effects of trehalose on pressure-induced inactivation of yeast alcohol dehydrogenase.

Isozymes of yeast alcohol dehydrogenase are slowly denatured at moderate hydrostatic pressures (<3 kbar). The time courses for inactivation are biphasic and both phases of both isozymes are protected by trehalose. ADH-I is slightly more barostable than ADH-II which is opposite to their thermostabilities. Trehalose at 1M extends their half-lives about 6-fold at 2 kbar, pH 7.5 and 25 degrees C. In contrast, 1M sucrose provides only 4.4-fold protection under identical conditions, a finding consistent with the superior protein stabilization of trehalose to other denaturants.

Alcohol Dehydrogenase↗
PubMed2004

Paclitaxel antibody conjugates and trehalose for preserving the immunological activity after freeze-drying.

Antibodies and anticancer drug-antibody conjugates used in experimental cancer research or clinically must be freeze-dried for preserving the activity and storage at room temperature. This often results in some denaturation and loss of activity. We describe a recovery of the cytotoxic activity of a paclitaxel-mAb immunoconjugate after freeze-drying. The paclitaxel-antibody conjugate specific for ovarian cancer was tested both for its cytotoxicity in vitro and immunological activity after freeze drying in the presence of various preservatives. Results show that the inclusion of trehalose as a stabilizer at concentrations varying from the 0.25 and 0.40 M protected the antibody and saved the pharmacological activity. When PEG alone or with trehalose was used, the immunological and cytotoxic activities recovery were lower. Albumin was not protective. This study shows that the addition of trehalose for freeze drying labile drug is a promising method for storage of large quantities of the immunoconjugates for experimental and therapeutic use.

Antibodies, Monoclonal↗
PubMedDate not supplied

In vitro stability of liposomes in the presence of polymers, trehalose and sodium taurocholate.

We report the influence of synthetic polymers, trehalose and sodium taurocholate on the stability of both MLVs* and SPLVs prepared from a range of lipids including synthetic polyhydroxyl lipids. In the absence of cryoprotective agents liposomes were found to release greater than 90 per cent of encapsulated marker when exposed to freeze-thawing or freeze-drying procedures. In the presence of polyvinylpalmitate a marginal enhancement of stability towards freeze-drying was observed, the effect being most marked with cholesterol-containing liposomes. Trehalose was also found to stabilize all preparations investigated towards freeze-drying. In particular SPLVS prepared from (C18:0, C14:0-GMG):EPC:C retained in greater than 90 per cent of the entrapped marker. Addition of polymers to trehalose-containing SPLVS did not further increase the stability. SPLVS prepared from lipids possessing a high transition temperature demonstrated enhanced stability in the presence of bile salts. This effect was most marked with SPLVs prepared from (C18:0, C22:0-GMG):C.

Bile Acids and Salts↗
PubMedDate not supplied

Trehalose-6-phosphate-potent anti-onchocerciatic agent.

Onchocerciasis is a disease that engages the attention of most researchers. Presently, there is not an ideal onchocerciatic agent, hence the search must continues. Consequently alpha, alpha-trehalose-6-phosphate was synthesised and assessed for onchocerciatic activity against O. volvulus; using diethylcarbamizine citrate as the control drug. Results from this study showed that alpha, alpha-trehalose-6-phosphate is a glucose analogue with effective micro and macro-filaricidal agent, better than that of the control drug. The inhibitory action of this compound on enzyme trehalase is a postulate for the mechanism of action of trehalose-6-phosphate. The structure-activity relationship of this new compound is fully discussed. This study postulates that this compound could be used to eradicate onchocerciasis both in man and animals.

Animals↗
PubMed1997

[Identification of Staphylococcus epidermidis by desferrioxamine susceptibility and trehalose fermentation tests].

The importance of coagulase-negative staphylococci, especially Staphylococcus epidermidis in clinical and nosocomial infection are recognized increasingly in recent years. A rapid and accurate identification of S. epidermidis is therefore important and necessary. A new test, susceptibility to desferrioxamine, coupled with trehalose fermentation has been recommended for the identification of this organism. However, the medium and method used are different from what has been recommended by the NCCLS. To investigate the feasibility of using the desferrioxamine susceptibility test in conjunction with the routinely used disc agar diffusion test, we employed 111 staphylococcal strains (including 51 S. epidermidis isolates, 15 S. hominis and 45 other coagulase-negative staphylococci) as test organisms, and followed the procedures recommended by the NCCLS in which Mueller-Hinton agar and standard inoculum were used. Results indicated that all strains of S. epidermidis and S. hominis were susceptible to 1 mg desferrioxamine (the diameter of the inhibition zone were 28-37 mm). The minimum inhibitory concentrations of desferrioxamine to S. epidermidis and S. hominis isolates were determined to be 125 micrograms/ml. Further differentiation of S. hominis and S. epidermidis can be made by their ability to ferment trehalose, the former could while the latter could not. We conclude that the desferrioxamine susceptibility test of coagulase-negative staphylococci can be used in conjunction with the routine disc agar diffusion method. S. epidermidis can be identified rapidly and accurately by its susceptibility to 1 mg desferrioxamine and inability to ferment trehalose.

Deferoxamine↗
PubMed2001

Analysis and modification of trehalose 6-phosphate levels in the yeast Saccharomyces cerevisiae with the use of Bacillus subtilis phosphotrehalase.

In the yeast Saccharomyces cerevisiae, trehalose is synthesized by the trehalose synthase complex in two steps. The Tps1 subunit catalyses the formation of trehalose 6-phosphate (Tre6P), which is dephosphorylated by the Tps2 subunit. Tps1 also controls sugar influx into glycolysis; a tps1 deletion strain is therefore unable to grow on glucose. It is unclear whether this regulatory function of Tps1 is mediated solely by Tre6P or also involves the Tps1 protein. We have developed a novel sensitive and specific assay method for Tre6P. It is based on the conversion of Tre6P into glucose and glucose 6-phosphate with purified phosphotrehalase from Bacillus subtilis. The glucose formed is measured with the glucose-oxidase/peroxidase method. The Tre6P assay is linear in the physiological concentration range. The detection limit, including the entire extraction procedure, is 15 nmol, corresponding to an intracellular concentration of 100 microM. To modify Tre6P levels in vivo, we expressed B. subtilis phosphotrehalase in yeast. The enzyme is functional because it rescues the temperature-sensitive growth defect of a tps2Delta strain and drastically lowers Tre6P levels in this strain. However, phosphotrehalase expression remains without effect on Tre6P levels in wild-type strains, as opposed to overexpression of Tps2. Because Tps2 is part of the Tre6P synthase (TPS) complex and because this complex is destabilized in tps2 deletion strains, these results can be explained if Tre6P is sequestered within the TPS complex in wild-type cells. The very low levels of Tre6P in cells overexpressing Tps2 have a limited effect on sugar phosphate accumulation and do not prevent growth on glucose. Taken together, our results support a model in which the regulatory function of Tps1 on sugar influx is mediated both by the Tps1 protein and by Tre6P.

Bacillus subtilis↗
PubMed1975

[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↗
PubMed2005

Optimal storage conditions for highly dilute DNA samples: a role for trehalose as a preserving agent.

DNA extraction from trace samples or noninvasively collected samples often results in the recovery of low concentration solutions of DNA that are prone to DNA degradation or other loss. Because of the difficulty in obtaining such samples, and their potentially high value in wildlife and forensic studies, it is critical that optimal methods are employed for their long-term storage. We assessed the amplification yield of samples kept under different storage conditions with the addition of potential preserving agents. We stored dilutions of known concentration human placental DNA, and gorilla fecal DNA, under four conditions (+4 degrees C, -20 degrees C, -80 degrees C, dry at room temperature), and with three additives (Tris EDTA (TE) buffer, Hind III digested Lambda DNA, trehalose). The effectiveness of the treatment methods was tested at regular intervals using qPCR to assess the quantity of amplifiable DNA, and a PCR assay of a larger 757 bp fragment to evaluate the quality of that remaining DNA. The highest quantity of DNA remained in samples stored at -80 degrees C, regardless of storage additives, and those dried at room temperature in the presence of trehalose. Surprisingly, DNA quality was best preserved in the presence of trehalose, either dried or at -80 degrees C; significant quality loss occurred with -20 degrees C and +4 degrees C storage.

Animals↗
PubMed2003

[The product identification study on the isolating process of strains produced trehalose].

In the isolating process of stains whose endocellular enzymes can produce trehalose on starch or maltooligosaccharides, we discovered the components of enzymatic reactant were complicated and it was difficult to purify them each other, however, we have to know quickly whether there was tehalose in the enzymatic reactant above. In order to make it clearly, thinner layer chromatography, high performance liquid chromatography-electrospray ionization mass spectrometry and 13C-nuclear magnetic resonance were adopted. The unknown oligosaccharide produced by Arthrobacter nicotinovorus D-97 was identified rapidly and this unknown oligosaccharide needn't be purified from the enzymatic reactant solely. The production on starch or maltooligosaccharides by endocellular enzymes of Arthrobacter nicotinovorus D-97 is trehalose. This research method in our paper can be applied in the isolating process of production trehalose and other functional glucobioses strains.

Arthrobacter↗
PubMed1991

Trehalose transport in yeast cells.

Saccharomyces cerevisiae possesses a specific transporter for trehalose. Transport is low until after glucose exhaustion in stationary phase, and addition of glucose in stationary phase results in loss of transport, an event that is reversible when the glucose is removed. The effect of glucose is not competitive inhibition: the increase in trehalose transport in stationary phase requires a lag time after glucose is depleted; and recovery of transport after glucose inhibition requires protein synthesis. Finally, we provide evidence that the trehalose transporter is distinct from that for maltose.

Binding, Competitive↗
PubMed1989

Fructose 2,6-bisphosphate and trehalose metabolism in Saccharomyces cerevisiae.

1. A regulatory mutant of Saccharomyces (fdp) unable to activate fructose 1,6-bisphosphatase presented a normal response to the glucose and fructose signals as measured by trehalase activation, indicating that the inability of the strain to grow on these sugars is caused by a defect located beyond membrane interactions. 2. In vivo experiments with a mutant strain bearing a phosphoglucoisomerase gene (pgil-delta) deletion showed that activation of trehalase and deactivation of the tehalose-6-phosphate synthase complex occurred to the same extent whether glucose or fructose was used as signal. 3. These results suggest that fructose-2,6-bisphosphate is not involved in the interconversion of forms of the enzymes of trehalose metabolism. Furthermore, when fructose-2,6-bisphosphate was assayed on trehalose synthesizing activity using cell-free extracts and partially purified preparations of the complex, no effect was observed. 4. We conclude that regulation by cAMP fulfills the requirements for control of trehalose levels in Saccharomyces.

Cyclic AMP↗
PubMed1987

Catabolite inactivation of trehalose synthesis during growth of yeast on maltose.

1. The effects of catabolite inactivation upon the trehalose pathway linked to maltose utilization were investigated in Saccharomyces cerevisiae. Mutant strains devoid of UDPG-trehalose synthase activity were used in this study. 2. Trehalose accumulation was also susceptible to catabolite inactivation as has been reported for the carrier protein, one of the components of the maltose system. Reversibility was only achieved when incubation with glucose did not exceed 5 min and was dependent upon protein synthesis.

Culture Media↗
PubMed1985

Investigation of the relationship between sst1 and fdp mutations in yeast and their effect on trehalose synthesis.

A specific deficiency in UDPG-linked trehalose-6-phosphate synthase in Saccharomyces has been associated with a single nuclear gene SST1 (M.S. Operti et al., Current Genetics, 5: 69-76, 1982). The sst1 phenotype was first observed in a pleiotropic fdp mutant which does not grow on mannose, sucrose, glucose or fructose, and in its partial spontaneous revertant (Q6R2) which acquired the capacity to grow on glucose but retained the mutant phenotype with respect to fructose. The sst1 mutants described in this paper are genetically derived from this partial revertant, a fact which suggested a link between sst1 and fdp mutations. All sst1 strains tested showed reduced growth on fructose in 24 h, which also characterizes the fdp mutation. Linkage studies revealed that the SST1 gene maps very close to the FDP gene. Furthermore, another mutant (cif) described as similar to fdp also lacked trehalose-6-phosphate synthase activity. Complementation tests between cif and fdp mutants indicated that the genes are allelic. These results suggest that SST1 and FDP are allelic and that the sst1 mutation might not be associated with the structural gene for trehalose-6-phosphate synthase but corresponds to one of the effects of the pleiotropic fdp mutation.

Alleles↗
PubMedDate not supplied

[Distribution of trehalose between the cells and the rehydration medium in dehydrated Saccharomyces cerevisiae].

The work was concerned with studying the balance of trehalose distribution between the rehydration medium and Saccharomyces cerevisiae cells grown in a chemically defined medium and dehydrated using the convective technique. A direct linear correlation between the viability of populations and the overall residual trehalose content in the cells and in the medium after the rehydration of dry yeast cells was shown to be most important. An inverse correlation was established between the viability of yeast cells and the amount of trehalose mobilised by the cells in the process of rehydration.

Culture Media↗