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1.
J Pharmacol Sci ; 156(2): 142-148, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39179333

RESUMEN

The hallmark of pathological cardiac hypertrophy is the decline in myocardial contractility caused by an energy deficit resulting from metabolic abnormalities, particularly those related to glucose metabolism. Here, we aim to explore whether D-Allose, a rare sugar that utilizes the same transporters as glucose, may restore metabolic equilibrium and reverse cardiac hypertrophy. Isolated neonatal rat cardiomyocytes were stimulated with phenylephrine and treated with D-Allose simultaneously for 48 h. D-Allose treatment resulted in a pronounced reduction in cardiomyocyte size and cardiac remodelling markers accompanied with a dramatic reduction in the level of intracellular glucose in phenylephrine-stimulated cells. The metabolic flux analysis provided further insights revealing that D-Allose exerted a remarkable inhibition of glycolysis as well as glycolytic capacity. Furthermore, in mice subjected to a 14-day continuous infusion of isoproterenol (ISO) to induce cardiac hypertrophy, D-Allose treatment via drinking water notably reduced ISO-induced cardiac hypertrophy and remodelling markers, with minimal effects on ventricular wall thickness observed in echocardiographic analyses. These findings indicate that D-Allose has the ability to attenuate the progression of cardiomyocyte hypertrophy by decreasing intracellular glucose flux and inhibiting glycolysis.


Asunto(s)
Cardiomegalia , Glucosa , Glucólisis , Isoproterenol , Miocitos Cardíacos , Fenilefrina , Animales , Cardiomegalia/tratamiento farmacológico , Cardiomegalia/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Glucólisis/efectos de los fármacos , Glucosa/metabolismo , Fenilefrina/farmacología , Masculino , Células Cultivadas , Ratones Endogámicos C57BL , Ratas , Ratones , Modelos Animales de Enfermedad , Ratas Sprague-Dawley
2.
Exp Gerontol ; 196: 112555, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39179160

RESUMEN

Age-related physical and cognitive decline may be ameliorated by consuming functional foods. d-Allose, reported to have multiple health benefits, may temper aging phenotypes, particularly brain function. We investigated whether d-allose supplementation improves cognitive function. A standard battery of behavioral tests was administered to 18-month-old male mice after consuming diet containing 3 % d-allose for 6 months. Following a wire-hanging test, an open-field test, Morris water maze, fear-conditioning, and an analgesia test were sequentially performed. Bone density and strength were assessed afterwards. Possible mechanism(s) under-lying memory changes in hippocampus were also examined with a DNA microarray. d-Allose failed to influence muscle strength, locomotor activity and anxiety, fear memory, or pain sensitivity. However, d-allose improved hippocampus-dependent spatial learning and memory, and it may contribute to increase bone strength. d-Allose also changed the expression of some genes in hippocampus involved in cognitive functions. Long-term d-allose supplementation appears to modestly change aging phenotypes and improve spatial memory.

3.
Sheng Wu Gong Cheng Xue Bao ; 40(7): 2010-2021, 2024 Jul 25.
Artículo en Chino | MEDLINE | ID: mdl-39044572

RESUMEN

D-allose, a rare sugar with anti-oxidant, anti-inflammatory, anti-cancer, immunosuppressing and other physiological functions, has become a research hotspot in recent years. This paper describes the physical and chemical properties, synthesis methods, metabolism, physiological functions, and applications of D-allose, aiming to promote the functional development of D-allose and facilitate the application of D-allose in the food field and clinical treatment.


Asunto(s)
Glucosa , Glucosa/metabolismo , Humanos , Antioxidantes/metabolismo , Antiinflamatorios/farmacología , Animales
4.
Crit Rev Food Sci Nutr ; : 1-28, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38764407

RESUMEN

D-allose, a C-3 epimer of D-glucose and an aldose-ketose isomer of D-allulose, exhibits 80% of sucrose's sweetness while being remarkably low in calories and nontoxic, making it an appealing sucrose substitute. Its diverse physiological functions, particularly potent anticancer and antitumor effects, render it a promising candidate for clinical treatment, garnering sustained attention. However, its limited availability in natural sources and the challenges associated with chemical synthesis necessitate exploring biosynthetic strategies to enhance production. This overview encapsulates recent advancements in D-allose's physicochemical properties, physiological functions, applications, and biosynthesis. It also briefly discusses the crucial role of understanding aldoketose isomerase structure and optimizing its performance in D-allose synthesis. Furthermore, it delves into the challenges and future perspectives in D-allose bioproduction. Early efforts focused on identifying and characterizing enzymes responsible for D-allose production, followed by detailed crystal structure analysis to improve performance through molecular modification. Strategies such as enzyme immobilization and implementing multi-enzyme cascade reactions, utilizing more cost-effective feedstocks, were explored. Despite progress, challenges remain, including the lack of efficient high-throughput screening methods for enzyme modification, the need for food-grade expression systems, the establishment of ordered substrate channels in multi-enzyme cascade reactions, and the development of downstream separation and purification processes.

5.
Heliyon ; 10(10): e30700, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38770322

RESUMEN

Rare sugars, which exist only in very small quantities in nature, have recently attracted attention for their various biological functions in medicine. Among them, d-allose is known to have cytoprotective effects by antioxidant effects. In this study, we investigated whether the antioxidant effects of d-allose reduce brain edema in a water intoxication model of cytotoxic brain edema. Methods: Mice were injected intraperitoneally with distilled water (10 % of body weight) to create a model of brain edema. d-allose was administered orally at 400 mg/kg 30 min before the model was created. Two hours later, the degree of brain edema was measured by the dry-weight method to determine whether d-allose reduced brain edema. As an index of antioxidant effects, we measured changes over time in inflammatory cytokines (tumor necrosis factor-alpha, interleukin-6) induced by the water intoxication model, and whether d-allose reduced inflammatory cytokines 4 h after model creation. Results: Administration of d-allose significantly suppressed brain edema formation of the water-intoxication model. And it significantly reduced inflammatory cytokines (tumor necrosis factor-alpha, interleukin-6). These results suggest that the antioxidant effect of d-allose exerts an anti-inflammatory effect and reduces brain edema.

6.
Appl Microbiol Biotechnol ; 108(1): 279, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38564031

RESUMEN

A novel L-rhamnose isomerase was identified and cloned from an extreme-temperature aquatic habitat metagenome. The deduced amino acid sequence homology suggested the possible source of this metagenomic sequence to be Chloroflexus islandicus. The gene expression was performed in a heterologous host, Escherichia coli, and the recombinant protein L-rhamnose isomerase (L-RIM) was extracted and purified. The catalytic function of L-RIM was characterized for D-allulose to D-allose bioconversion. D-Allose is a sweet, rare sugar molecule with anti-tumour, anti-hypertensive, cryoprotective, and antioxidative properties. The characterization experiments showed L-RIM to be a Co++- or Mn++-dependent metalloenzyme. L-RIM was remarkably active (~ 80%) in a broad spectrum of pH (6.0 to 9.0) and temperature (70 to 80 °C) ranges. Optimal L-RIM activity with D-allulose as the substrate occurred at pH 7.0 and 75 °C. The enzyme was found to be excessively heat stable, displaying a half-life of about 12 days and 5 days at 65 °C and 70 °C, respectively. L-RIM catalysis conducted at slightly acidic pH of 6.0 and 70 °C achieved biosynthesis of about 30 g L-1 from 100 g L-1 D-allulose in 3 h. KEY POINTS: • The present study explored an extreme temperature metagenome to identify a novel gene that encodes a thermostable l-rhamnose isomerase (L-RIM) • L-RIM exhibits substantial (80% or more) activity in a broad spectrum of pH (6.0 to 9.0) and temperature (70 to 80 °C) ranges • L-RIM is excessively heat stable, displaying a half-life of about 12 days and 5 days at 65 °C and 70 °C, respectively.


Asunto(s)
Isomerasas Aldosa-Cetosa , Fructosa , Glucosa , Antihipertensivos , Escherichia coli/genética
7.
Molecules ; 29(8)2024 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-38675593

RESUMEN

Rare sugars are known for their ability to suppress postprandial blood glucose levels. Therefore, oligosaccharides and disaccharides derived from rare sugars could potentially serve as functional sweeteners. A disaccharide [α-d-allopyranosyl-(1→2)-ß-d-psicofuranoside] mimicking sucrose was synthesized from rare monosaccharides D-allose and D-psicose. Glycosylation using the intermolecular aglycon delivery (IAD) method was employed to selectively form 1,2-cis α-glycosidic linkages of the allopyranose residues. Moreover, ß-selective psicofuranosylation was performed using a psicofuranosyl acceptor with 1,3,4,6-tetra-O-benzoyl groups. This is the first report on the synthesis of non-reducing disaccharides comprising only rare d-sugars by IAD using protected ketose as a unique acceptor; additionally, this approach is expected to be applicable to the synthesis of functional sweeteners.


Asunto(s)
Disacáridos , Fructosa , Glucosa , Sacarosa , Disacáridos/química , Disacáridos/síntesis química , Sacarosa/química , Glicosilación , Edulcorantes/química
8.
Anticancer Res ; 44(5): 1895-1903, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38677730

RESUMEN

BACKGROUND/AIM: The present study investigated the anticancer effects of intraperitoneally administered D-allose in in vivo models of head and neck cancer cell lines. MATERIALS AND METHODS: To assess the direct effects of D-allose, its dynamics in blood and tumor tissues were examined. RESULTS: D-allose was detected in blood and tumor tissues 10 min after its intraperitoneal administration and then gradually decreased. In vivo experiments revealed that radiation plus D-allose was more effective than either treatment alone. Thioredoxin-interacting protein (TXNIP) mRNA over-expression was detected after the addition of D-allose in in vitro and in vivo experiments. D-allose inhibited cell growth, which was associated with decreases in glycolysis and intracellular ATP levels and the prolonged activation of AMPK. The phosphorylation of p38-MAPK was also observed early after the administration of D-allose and was followed by the activation of AMPK and up-regulated expression of TXNIP in both in vitro and in vivo experiments. CONCLUSION: Systemically administered D-allose appears to exert antitumor effects. Further studies are needed to clarify the appropriate dosage and timing of the administration of D-allose and its combination with other metabolic agents.


Asunto(s)
Glucosa , Neoplasias de Cabeza y Cuello , Animales , Humanos , Masculino , Ratones , Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Glucosa/metabolismo , Glucólisis/efectos de los fármacos , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/radioterapia , Neoplasias de Cabeza y Cuello/genética , Ratones Desnudos , Ensayos Antitumor por Modelo de Xenoinjerto
9.
Food Sci Biotechnol ; 33(7): 1641-1649, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38623425

RESUMEN

Enzymatic preparation of rare sugars as an alternative to traditional sweeteners is an effective strategy to achieve a low-calorie healthy diet. Ribose-5-phosphate isomerase B (RpiB) is a key enzyme in the non-oxidative branch of the catalytic pentose phosphate pathway. Here, we investigated the potential of Curtobacterium flaccumfaciens ZXL1 (C. flaccumfaciens ZXL1) derived RpiB (CfRpiB) in D-allose preparation. The optimal reaction conditions for recombinant CfRpiB were found experimentally to be pH 7.0, 55 °C, and no metal ions. The kinetic parameters Km, kcat, and catalytic efficiency kcat/Km were 320 mM, 4769 s-1, and 14.9 mM-1 s-1 respectively. The conversion of D-allulose by purified enzyme (1 g L-1 ) to D-allose was 13% within 1 h. In addition, homology modeling and molecular docking were used to predict the active site residues: Asp13, Asp14, Cys72, Gly73, Thr74, Gly77, Asn106, and Lys144.

10.
J Pharmacol Sci ; 154(4): 274-278, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38485345

RESUMEN

2-Deoxy-d-glucose (2DG) induces anticancer effects through glycolytic inhibition but it may raise the risk of arrhythmia. The rare monosaccharide d-allose also has anticancer properties, but its cardiac effects are unknown. We examined the effects of d-allose on adenosine triphosphate (ATP) production in neonatal rat cardiomyocytes. We showed that 25 mM d-allose selectively reduced glycolytic ATP, but had minimal impact on mitochondrial ATP, while 1 mM 2DG strongly inhibited both. Furthermore, d-allose had less impact on cell viability and was less cytotoxic than 2DG; neither compound caused apoptosis. Thus, d-allose selectively diminished glycolytic ATP production with no apparent effects on cardiomyocytes.


Asunto(s)
Adenosina Trifosfato , Miocitos Cardíacos , Ratas , Animales , Animales Recién Nacidos , Supervivencia Celular , Glucosa/farmacología
11.
Appl Microbiol Biotechnol ; 108(1): 249, 2024 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-38430263

RESUMEN

A recombinant L-rhamnose isomerase (L-RhI) from probiotic Lactobacillus rhamnosus Probio-M9 (L. rhamnosus Probio-M9) was expressed. L. rhamnosus Probio-M9 was isolated from human colostrum and identified as a probiotic lactic acid bacterium, which can grow using L-rhamnose. L-RhI is one of the enzymes involved in L-rhamnose metabolism and catalyzes the reversible isomerization between L-rhamnose and L-rhamnulose. Some L-RhIs were reported to catalyze isomerization not only between L-rhamnose and L-rhamnulose but also between D-allulose and D-allose, which are known as rare sugars. Those L-RhIs are attractive enzymes for rare sugar production and have the potential to be further improved by enzyme engineering; however, the known crystal structures of L-RhIs recognizing rare sugars are limited. In addition, the optimum pH levels of most reported L-RhIs are basic rather than neutral, and such a basic condition causes non-enzymatic aldose-ketose isomerization, resulting in unexpected by-products. Herein, we report the crystal structures of L. rhamnosus Probio-M9 L-RhI (LrL-RhI) in complexes with L-rhamnose, D-allulose, and D-allose, which show enzyme activity toward L-rhamnose, D-allulose, and D-allose in acidic conditions, though the activity toward D-allose was low. In the complex with L-rhamnose, L-rhamnopyranose was found in the catalytic site, showing favorable recognition for catalysis. In the complex with D-allulose, D-allulofuranose and ring-opened D-allulose were observed in the catalytic site. However, bound D-allose in the pyranose form was found in the catalytic site of the complex with D-allose, which was unfavorable for recognition, like an inhibition mode. The structure of the complex may explain the low activity toward D-allose. KEY POINTS: • Crystal structures of LrL-RhI in complexes with substrates were determined. • LrL-RhI exhibits enzyme activity toward L-rhamnose, D-allulose, and D-allose. • The LrL-RhI is active in acidic conditions.


Asunto(s)
Isomerasas Aldosa-Cetosa , Lacticaseibacillus rhamnosus , Humanos , Rayos X , Ramnosa , Monosacáridos
12.
Int J Biol Macromol ; 254(Pt 2): 127859, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37924916

RESUMEN

D-Allose and D-allulose are two important rare natural monosaccharides found in meager amounts. They are considered to be the ideal substitutes for table sugar (sucrose) for, their significantly lower calorie content with around 80 % and 70 % of the sweetness of sucrose, respectively. Additionally, both monosaccharides have gained much attention due to their remarkable physiological properties and excellent health benefits. Nevertheless, D-allose and D-allulose are rare in nature and difficult to produce by chemical methods. Consequently, scientists are exploring bioconversion methods to convert D-allulose into D-allose, with a key enzyme, L-rhamnose isomerase (L-RhIse), playing a remarkable role in this process. This review provides an in-depth analysis of the extractions, physiological functions and applications of D-allose from D-allulose. Specifically, it provides a detailed description of all documented L-RhIse, encompassing their biochemical properties including, pH, temperature, stabilities, half-lives, metal ion dependence, molecular weight, kinetic parameters, specific activities and specificities of the substrates, conversion ratio, crystal structure, catalytic mechanism as well as their wide-ranging applications across diverse fields. So far, L-RhIses have been discovered and characterized experimentally by numerous mesophilic and thermophilic bacteria. Furthermore, the crystal forms of L-RhIses from E. coli and Stutzerimonas/Pseudomonas stutzeri have been previously cracked, together with their catalytic mechanism. However, there is room for further exploration, particularly the molecular modification of L-RhIse for enhancing its catalytic performance and thermostability through the directed evolution or site-directed mutagenesis.


Asunto(s)
Escherichia coli , Fructosa , Escherichia coli/metabolismo , Fructosa/química , Monosacáridos/metabolismo , Sacarosa/metabolismo
13.
Perit Dial Int ; 44(2): 125-132, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37525525

RESUMEN

BACKGROUND: Peritoneal dialysis (PD) is a crucial dialysis method for treating end-stage kidney disease. However, its use is restricted due to high glucose-induced peritoneal injury and hyperglycaemia, particularly in patients with diabetes mellitus. In this study, we investigated whether partially replacing d-glucose with the rare sugar d-allose could ameliorate peritoneal injury and hyperglycaemia induced by peritoneal dialysis fluid (PDF). METHODS: Rat peritoneal mesothelial cells (RPMCs) were exposed to a medium containing d-glucose or d-glucose partially replaced with different concentrations of d-allose. Cell viability, oxidative stress and cytokine production were evaluated. Sprague-Dawley (SD) rats were administrated saline, a PDF containing 4% d-glucose (PDF-G4.0%) or a PDF containing 3.6% d-glucose and 0.4% d-allose (PDF-G3.6%/A0.4%) once a day for 4 weeks. Peritoneal injury and PD efficiency were assessed using immuno-histological staining and peritoneal equilibration test, respectively. Blood glucose levels were measured over 120 min following a single injection of saline or PDFs to 24-h fasted SD rats. RESULTS: In RPMCs, the partial replacement of d-glucose with d-allose increased cell viability and decreased oxidative stress and cytokine production compared to d-glucose alone. Despite the PDF-G3.6%/A0.4% having a lower d-glucose concentration compared to PDF-G4.0%, there were no significant changes in osmolality. When administered to SD rats, the PDF-G3.6%/A0.4% suppressed the elevation of peritoneal thickness and blood d-glucose levels induced by PDF-G4.0%, without impacting PD efficiency. CONCLUSIONS: Partial replacement of d-glucose with d-allose ameliorated peritoneal injury and hyperglycaemia induced by high concentration of d-glucose in PDF, indicating that d-allose could be a potential treatment option in PD.


Asunto(s)
Hiperglucemia , Diálisis Peritoneal , Humanos , Ratas , Animales , Diálisis Peritoneal/efectos adversos , Diálisis Peritoneal/métodos , Hiperglucemia/patología , Ratas Sprague-Dawley , Soluciones para Diálisis/efectos adversos , Peritoneo/patología , Glucosa , Citocinas
14.
Biol Proced Online ; 25(1): 30, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38017376

RESUMEN

BACKGROUND: Ischemic stroke (IS) occurs when a blood vessel supplying the brain becomes obstructed, resulting in cerebral ischemia. This type of stroke accounts for approximately 87% of all strokes. Globally, IS leads to high mortality and poor prognosis and is associated with neuroinflammation and neuronal apoptosis. D-allose is a bio-substrate of glucose that is widely expressed in many plants. Our previous study showed that D-allose exerted neuroprotective effects against acute cerebral ischemic/reperfusion (I/R) injury by reducing neuroinflammation. Here, we aimed to clarify the beneficial effects D-allose in suppressing IS-induced neuroinflammation damage, cytotoxicity, neuronal apoptosis and neurological deficits and the underlying mechanism in vitro and in vivo. METHODS: In vivo, an I/R model was induced by middle cerebral artery occlusion and reperfusion (MCAO/R) in C57BL/6 N mice, and D-allose was given by intraperitoneal injection within 5 min after reperfusion. In vitro, mouse hippocampal neuronal cells (HT-22) with oxygen-glucose deprivation and reperfusion (OGD/R) were established as a cell model of IS. Neurological scores, some cytokines, cytotoxicity and apoptosis in the brain and cell lines were measured. Moreover, Gal-3 short hairpin RNAs, lentiviruses and adeno-associated viruses were used to modulate Gal-3 expression in neurons in vitro and in vivo to reveal the molecular mechanism. RESULTS: D-allose alleviated cytotoxicity, including cell viability, LDH release and apoptosis, in HT-22 cells after OGD/R, which also alleviated brain injury, as indicated by lesion volume, brain edema, neuronal apoptosis, and neurological functional deficits, in a mouse model of I/R. Moreover, D-allose decreased the release of inflammatory factors, such as IL-1ß, IL-6 and TNF-α. Furthermore, the expression of Gal-3 was increased by I/R in wild-type mice and HT-22 cells, and this factor further bound to TLR4, as confirmed by three-dimensional structure prediction and Co-IP. Silencing the Gal-3 gene with shRNAs decreased the activation of TLR4 signaling and alleviated IS-induced neuroinflammation, apoptosis and brain injury. Importantly, the loss of Gal-3 enhanced the D-allose-mediated protection against I/R-induced HT-22 cell injury, inflammatory insults and apoptosis, whereas activation of TLR4 by the selective agonist LPS increased the degree of neuronal injury and abolished the protective effects of D-allose. CONCLUSIONS: In summary, D-allose plays a crucial role in inhibiting inflammation after IS by suppressing Gal-3/TLR4/PI3K/AKT signaling pathway in vitro and in vivo.

15.
J Agric Food Chem ; 71(42): 15713-15722, 2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37823838

RESUMEN

d-Allose is a low-calorie rare sugar with great application potential in the food and pharmaceutical industries. The production of d-allose has been accomplished using l-rhamnose isomerase (L-RI), but concomitantly increasing the enzyme's stability and activity remains challenging. Here, we rationally engineered an L-RI from Clostridium stercorarium to enhance its stability by comprehensive computation-aided redesign of its flexible regions, which were successively identified using molecular dynamics simulations. The resulting combinatorial mutant M2-4 exhibited a 5.7-fold increased half-life at 75 °C while also exhibiting improved catalytic efficiency. Especially, by combining structure modeling and multiple sequence alignment, we identified an α0 region that was universal in the L-RI family and likely acted as a "helix-breaker". Truncating this region is crucial for improving the thermostability of related enzymes. Our work provides a significantly stable biocatalyst with potential for the industrial production of d-allose.


Asunto(s)
Isomerasas Aldosa-Cetosa , Proteínas Bacterianas , Proteínas Bacterianas/genética , Proteínas Bacterianas/química , Glucosa/química , Isomerasas Aldosa-Cetosa/química , Estabilidad de Enzimas
16.
Biochem Biophys Res Commun ; 682: 187-192, 2023 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-37820454

RESUMEN

d-Allose is an aldohexose of the C3-epimer of d-glucose, existing in very small amounts in nature, called a rare sugar. The operon responsible for d-allose metabolism, the allose operon, was found in several bacteria, which consists of seven genes: alsR, alsB, alsA, alsC, alsE, alsK, and rpiB. To understand the biological implication of the allose operon utilizing a rare sugar of d-allose as a carbon source, it is important to clarify whether the allose operon functions specifically for d-allose or also functions for other ligands. It was proposed that the allose operon can function for d-ribose, which is essential as a component of nucleotides and abundant in nature. Allose-binding protein, AlsB, coded in the allose operon, is thought to capture a ligand outside the cell, and is expected to show high affinity for the specific ligand. X-ray structure determinations of Enterobacter cloacae AlsB (EtcAlsB) in ligand-free form, and in complexes with d-allose, d-ribose, and d-allulose, and measurements of the thermal parameters of the complex formation using an isothermal titration calorimeter were performed. The results demonstrated that EtcAlsB has a unique recognition mechanism for high affinity to d-allose by changing its conformation from an open to a closed form depending on d-allose-binding, and that the binding of d-ribose to EtcAlsB could not induce a completely closed form but an intermediate form, explaining the low affinity for d-ribose.


Asunto(s)
Proteínas Portadoras , Monosacáridos , Proteínas Portadoras/metabolismo , Enterobacter cloacae/genética , Enterobacter cloacae/metabolismo , Rayos X , Ligandos , Ribosa/metabolismo , Glucosa/metabolismo
17.
Front Cell Infect Microbiol ; 13: 1162918, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37545855

RESUMEN

A rare sugar, allose, was reported to inhibit the development of Plasmodium parasites in Anopheles mosquitoes; however, the mechanism remains unknown. The present study addressed the inhibitory mechanism of allose on the development of the Plasmodium parasite by connecting it with bacteria involvement in the midgut. In addition, further inhibitory sugars against Plasmodium infection in mosquitoes were explored. Antibiotic-treated and antibiotic-untreated Anopheles stephensi were fed fructose with or without allose. The mosquitoes were infected with luciferase-expressing Plasmodium berghei, and parasite development was evaluated by luciferase activity. Bacterial composition analysis in gut of their mosquitoes was performed with comprehensive 16S ribosomal RNA sequencing. As the result, allose inhibited the development of oocysts in mosquitoes regardless of prior antibiotic treatment. Microbiome analysis showed that the midgut bacterial composition in mosquitoes before and after blood feeding was not affected by allose. Although allose inhibited transient growth of the midgut microbiota of mosquitoes after blood feeding, neither toxic nor inhibitory effects of allose on the dominant midgut bacteria were observed. Ookinete development in the mosquito midgut was also not affected by allose feeding. Additional 15 sugars including six monosaccharides, four polyols, and five polysaccharides were tested; however, no inhibitory effect against Plasmodium development in mosquitoes was observed. These results indicated that allose inhibits parasite development in midgut stage of the mosquito independently of midgut microbiota. Although further studies are needed, our results suggest that allose may be a useful material for the vector control of malaria as a "transmission-blocking sugar."


Asunto(s)
Anopheles , Malaria , Microbiota , Parásitos , Animales , Anopheles/parasitología , Azúcares , Mosquitos Vectores , Carbohidratos , Plasmodium berghei , Malaria/parasitología , Bacterias
18.
J Food Prot ; 86(7): 100104, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37178924

RESUMEN

Testing of foods for low levels of the human pathogen, Listeria monocytogenes (Lm), involves a selective enrichment procedure. A nonpathogenic species of Listeria, L. innocua (Li), is often present in foods and food-manufacturing environments and is an interference organism for Lm detection due to competition during enrichment. The present study investigated whether a novel enrichment strategy incorporating the sugar allose into the secondary enrichment broth (allose method) could improve the detection of Lm from foods when Li is present. First, Canadian food isolates of Listeria spp. were tested to confirm recent reports that lineage II Lm (LII-Lm), but not Li, could metabolize allose. All LII-Lm isolates (n = 81), but not Li (n = 36), possessed the allose genes lmo0734-lmo0739, and could efficiently metabolize allose. Next, smoked salmon was contaminated with mixtures of LII-Lm and Li and tested using different enrichment procedures to compare the ability to recover Lm. Allose broth was more effective than Fraser Broth, with Lm detected in 87% (74 of 85) compared to 59% (50 of 85) of the samples (P < 0.05), following a common preenrichment. When evaluated against a current Health Canada method (MFLP-28), the allose method was more effective, with LII-Lm detected in 88% (57 of 65) compared to 69% (45 of 65) of the samples (P < 0.05). The allose method also remarkably increased the ratio of LII-Lm to Li postenrichment, which improved the ease of obtaining isolated Lm colonies for confirmation tests. Allose may therefore provide a tool for use when the presence of background flora interferes with Lm detection. As this tool is specifically applicable to a subset of Lm, the use of this method modification may provide a working example of tailoring methodology to target the known subtype of the pathogen of interest in an outbreak investigation, or for regular monitoring activities in conjunction with a PCR screen for allose genes on preenrichment cultures.


Asunto(s)
Listeria monocytogenes , Listeria , Humanos , Microbiología de Alimentos , Canadá , Alimentos Marinos , Medios de Cultivo
19.
Enzyme Microb Technol ; 168: 110259, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37245327

RESUMEN

D-Allose is a rare cis-caprose with a wide range of physiological functions, which has a wide range of applications in medicine, food, and other industries. L-Rhamnose isomerase (L-Rhi) is the earliest enzyme found to catalyze the production of D-allose from D-psicose. This catalyst has a high conversion rate, but its specificity for substrates is limited; thus, it cannot fulfill the requirements of industrial production of D-allose. In this study, L-Rhi derived from Bacillus subtilis was employed as the research subject, and D-psicose as the conversion substrate. Two mutant libraries were constructed through alanine scanning, saturation mutation, and rational design based on the analysis of the secondary structure, tertiary structure, and interactions with ligands of the enzyme. The yield of D-allose produced by these mutants was assessed; it was found that the conversion rate of mutant D325M to D-allose was increased by 55.73 %, and the D325S improved by 15.34 %, while mutant W184H increased by 10.37 % at 55 °C, respectively. According to modeling analysis, manganese (Mn2+) had no significant effect on the production of D-psicose from D-psicose by L-Rhi. The results of molecular dynamics simulation demonstrated that the mutants W184H, D325M, and D325S had more stable protein structures while binding with the substrate D-psicose, as evidenced by its root mean square deviation (RMSD), root mean square fluctuation (RMSF), and binding free energy values. It was more conducive to binding D-psicose and facilitating its conversion to D-allose, providing the basis for the production of D-allose.


Asunto(s)
Isomerasas Aldosa-Cetosa , Glucosa , Glucosa/metabolismo , Fructosa/metabolismo , Isomerasas Aldosa-Cetosa/metabolismo , Mutación
20.
Curr Mol Pharmacol ; 16(8): 801-810, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36578261

RESUMEN

BACKGROUND: Despite the implementation of various cancer therapies, adequate therapeutic efficacy has not been achieved. A growing number of studies have been dedicated to the discovery of new molecules to combat refractory cancer cells efficiently. Recently, the use of a rare type of sugar, D-allose, has attracted the attention of research communities. In combination with the first-line treatment of cancers, including different types of radiotherapies and chemotherapies, D-allose has been detected with favorable complementary effects. Understanding the mechanism of therapeutic target molecules will enable us to develop new strategies for cancer patients that do not currently respond to the present therapies. OBJECTIVE: We aimed to provide a review of the effects of D-allose in cancer treatment, its mechanisms of action, and gaps in this field that require more investigations. DISCUSSION: With rare exceptions, in many cancer types, including head and neck, lung, liver, bladder, blood, and breast, D-allose consistently has exhibited anticancer activity in vitro and/or in vivo. Most of the D-allose functions are mediated through thioredoxin-interacting protein molecules. D-allose exerts its effects via reactive oxygen species regulation, cell cycle arrest, metabolic reprogramming, autophagy, apoptosis induction, and sensitizing tumors to radiotherapy and chemotherapy. CONCLUSION: D-allose has shown great promise for combating tumor cells with no side effects, especially in combination with first-line drugs; however, its potential for cancer therapy has not been comprehensively investigated in vitro or in vivo.


Asunto(s)
Glucosa , Neoplasias , Humanos , Proliferación Celular , Línea Celular Tumoral , Glucosa/metabolismo , Glucosa/farmacología , Neoplasias/tratamiento farmacológico
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