Topic
Trehalase
About: Trehalase is a research topic. Over the lifetime, 1204 publications have been published within this topic receiving 33751 citations.
Papers published on a yearly basis
1 / 2
Papers
TL;DR: This sugar is present in a wide variety of organisms, including bacteria, yeast, fungi, insects, invertebrates, and lower and higher plants, where it may serve as a source of energy and carbon and as a signaling molecule to direct or control certain metabolic pathways or even to affect growth.
Abstract: Trehalose is a nonreducing disaccharide in which the two glucose units are linked in an alpha,alpha-1,1-glycosidic linkage. This sugar is present in a wide variety of organisms, including bacteria, yeast, fungi, insects, invertebrates, and lower and higher plants, where it may serve as a source of energy and carbon. In yeast and plants, it may also serve as a signaling molecule to direct or control certain metabolic pathways or even to affect growth. In addition, it has been shown that trehalose can protect proteins and cellular membranes from inactivation or denaturation caused by a variety of stress conditions, including desiccation, dehydration, heat, cold, and oxidation. Finally, in mycobacteria and corynebacteria, trehalose is an integral component of various glycolipids that are important cell wall structures. There are now at least three different pathways described for the biosynthesis of trehalose. The best known and most widely distributed pathway involves the transfer of glucose from UDP-glucose (or GDP-glucose in some cases) to glucose 6-phosphate to form trehalose-6-phosphate and UDP. This reaction is catalyzed by the trehalose-P synthase (TPS here, or OtsA in Escherichia coli ). Organisms that use this pathway usually also have a trehalose-P phosphatase (TPP here, or OtsB in E. coli) that converts the trehalose-P to free trehalose. A second pathway that has been reported in a few unusual bacteria involves the intramolecular rearrangement of maltose (glucosyl-alpha1,4-glucopyranoside) to convert the 1,4-linkage to the 1,1-bond of trehalose. This reaction is catalyzed by the enzyme called trehalose synthase and gives rise to free trehalose as the initial product. A third pathway involves several different enzymes, the first of which rearranges the glucose at the reducing end of a glycogen chain to convert the alpha1,4-linkage to an alpha,alpha1,1-bond. A second enzyme then releases the trehalose disaccharide from the reducing end of the glycogen molecule. Finally, in mushrooms there is a trehalose phosphorylase that catalyzes the phosphorolysis of trehalose to produce glucose-1-phosphate and glucose. This reaction is reversible in vitro and could theoretically give rise to trehalose from glucose-1-P and glucose. Another important enzyme in trehalose metabolism is trehalase (T), which may be involved in energy metabolism and also have a regulatory role in controlling the levels of trehalose in cells. This enzyme may be important in lowering trehalose concentrations once the stress is alleviated. Recent studies in yeast indicate that the enzymes involved in trehalose synthesis (TPS, TPP) exist together in a complex that is highly regulated at the activity level as well as at the genetic level.
1,903 citations
TL;DR: It is concluded that trehalose is safe for use as an ingredient in consumer products when used in accordance with current Good Manufacturing Practices.
571 citations
TL;DR: In this paper, the role of trehalose in the growth of Mycobacterium smegmutis under various conditions of nitrogen limitation was examined, and the results of labeling studies suggested that the free trehaloses in these cells may be utilized for purposes except as an energy reserve, whereas glycogen is probably stored mainly as a reserve.
Abstract: Publisher Summary This chapter discusses the metabolism of α,α-trehalose. The chapter outlines the various reactions that have been shown to be involved in the metabolism of trehalose. The other isomers of trehalose containing D-glucopyranose—that is, α,β-trehalose and β,β-trehalose have been synthesized chemically. However, except for a few rare cases, these isomers of trehalose do not appear to be naturally occurring. The mechanism of biosynthesis of α,α-trehalose. To determine the role of trehalose in Mycobacterium the levels of free and “bound” (that is, lipid-associated) trehalose and glycogen during growth of Mycobacterium smegmutis under various conditions of nitrogen limitation is examined. Whereas the glycogen levels increased markedly as the nitrogen content of the medium was lowered, the levels of trehalose remained fairly constant. The results of labeling studies suggested that the free trehalose in these cells may be utilized for purposes except as an energy reserve, whereas glycogen is probably stored mainly as a reserve. Synthesis and degradation of trehalose constitute a mechanism for the resorption of D-glucose in the kidney and, perhaps, also in the intestine. It has also been suggested that trehalose—like another naturally occurring, nonreducing disaccharide, sucrose—could function in the movement of carbohydrate, .i.e., as a translocate in plants or insects, or both.
534 citations
TL;DR: Trehalose is the principal sugar circulating in the blood or haemolymph of most insects, and is a component of a feedback mechanism regulating feeding behaviour and nutrient intake, where blood metabolite levels including trehalose act through modulation of taste receptor responses and through the central nervous system to influence food selection.
Abstract: Trehalose, the non-reducing disaccharide of glucose, is the principal sugar circulating in the blood or haemolymph of most insects. Resistance to acid hydrolysis and an absence of direct intramolecular hydrogen bonding make trehalose chemically unique when compared with other common disaccharides, particularly sucrose, the non-reducing disaccharide of plant origin. Synthesized in the fat body following digestion of dietary sugar, trehalose is a condensation product of two glycolytic intermediates, glucose-1-phosphate and glucose-6-phosphate. Alternative sources of trehalose are glycogen breakdown and gluconeogenesis. Hydrolysis to reform glucose, catalyzed by isozymes of a single enzyme, trehalase, is the only known pathway of trehalose utilization. Trehalose synthesis and degradation are under hormonal control involving both hypertrehalosemic and hypotrehalosemic factors. Trehalose concentration in the blood, however, is not homeostatically regulated. Rather, trehalose occurs at highly variable levels, typically between 5 and 50 m m , depending on environmental conditions, physiological state and nutrition. This variable concentration is essential for fulfilling the roles of trehalose, as (1) an energy store, the traditional role ascribed to trehalose; (2) a cryoprotectant, reducing the supercooling point of some freeze-avoiding insects; (3) a protein stabilizer during osmotic and thermal stress, a function only recently investigated in insects, and (4) a component of a feedback mechanism regulating feeding behaviour and nutrient intake, where blood metabolite levels including trehalose act through modulation of taste receptor responses and through the central nervous system to influence food selection. These are all examples of functional conservation in the absence of homeostasis. This has been termed enantiostasis, where functional conservation serves as a mechanism of physiological adaptation despite what appears to be an unstable internal milieu.
433 citations
TL;DR: The one-step procedure for disaccharidase activity assay is conveniently veniently used on the ultramicro scale, and the method then utilizes only about 1 25 of the amount of tissue needed for a previously described two-step method, which is therefore especially suitable for the analysis of pieces of mucosa obtained by peroral capsular biopsy.
420 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 7 |
| 2024 | 27 |
| 2023 | 24 |
| 2022 | 48 |
| 2021 | 26 |
| 2020 | 29 |