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Objectives: Special aerial gymnastics instruments (SAGI) are permanent elements of specialist training for cadet pilots. Appropriate physical activity and fitness are essential for performing the tasks of military pilots. Therefore, one of the main goals of cadet training is to develop adaptation to the extreme conditions of a military pilot's work. This study aimed to determine the effect of the SAGI training process for cadet pilots on their aldolase and lactate dehydrogenase (LDH) activity, LDH enzymatic index (iZO), C-reactive protein (CRP) and haptoglobin (HP) levels, and physical fitness. Material and Methods: Participating in this study were 55 cadets, aged 20 ± 0.70 years, in two groups. In group A (n = 41, tested) cadets were trained on SAGI with an emphasis on endurance and strength. In group B (n = 14, control), the cadets performed general fitness training. Blood samples were collected before and after training series I, II, and III. LDH and its isoenzyme activity, aldolase, CRP, and HP levels were assayed in blood serum using commercially available tests, and the iZO value was calculated. Results: A downward trend was observed in HP and CRP levels in both groups after all three training series. In group A after training, LDH and aldolase activity was lower than in group B. However, in both groups, a significant increase of iZO values was observed after training series II and III in group A, p < 0.001, p < 0.05, respectively, and in group B, p < 0.05 and p < 0.0005, respectively. Physical fitness also improved in both groups. Conclusion: The course of the SAGI exercises showed that the iZO value depends on physical exercise intensity, its type, and cadet adaptation. [ABSTRACT FROM AUTHOR]

Methanogenic archaea are chemolithotrophic prokaryotes that can reduce carbon dioxide with hydrogen gas to form methane. These microorganisms make a significant contribution to the global carbon cycle, with methanogenic archaea from anoxic environments estimated to contribute > 500 million tons of global methane annually. Archaeal methanogenesis is dependent on the methanofurans; aminomethylfuran containing coenzymes that act as the primary C1 acceptor molecule during carbon dioxide fixation. Although the biosynthetic pathway to the methanofurans has been elucidated, structural adaptations which confer thermotolerance to Mfn enzymes from extremophilic archaea are yet to be investigated. Here we focus on the methanofuran biosynthetic enzyme MfnB, which catalyses the condensation of two molecules of glyceralde-3-phosphate to form 4‑(hydroxymethyl)-2-furancarboxaldehyde-phosphate. In this study, MfnB enzymes from the hyperthermophile Methanocaldococcus jannaschii and the mesophile Methanococcus maripaludis have been recombinantly overexpressed and purified to homogeneity. Thermal unfolding studies, together with steady-state kinetic assays, demonstrate thermoadaptation in the M. jannaschii enzyme. Molecular dynamics simulations have been used to provide a structural explanation for the observed properties. These reveal a greater number of side chain interactions in the M. jannaschii enzyme, which may confer protection from heating effects by enforcing spatial residue constraints. [ABSTRACT FROM AUTHOR]

Reelin, a secreted glycoprotein, plays a crucial role in guiding neocortical neuronal migration, dendritic outgrowth and arborization, and synaptic plasticity in the adult brain. Reelin primarily operates through the canonical lipoprotein receptors apolipoprotein E receptor 2 (Apoer2) and very low-density lipoprotein receptor (Vldlr). Reelin also engages with noncanonical receptors and unidentified coreceptors; however, the effects of which are less understood. Using high-throughput tandem mass tag (TMT) liquid chromatography tandem mass spectrometry (LC-MS/MS)-based proteomics and gene set enrichment analysis (GSEA), we identified both shared and unique intracellular pathways activated by Reelin through its canonical and noncanonical signaling in primary murine neurons of either sex during dendritic growth and arborization. We observed pathway cross talk related to regulation of cytoskeleton, neuron projection development, protein transport, and actin filament-based process. We also found enriched gene sets exclusively by the noncanonical Reelin pathway including protein translation, mRNA metabolic process, and ribonucleoprotein complex biogenesis suggesting Reelin fine-tunes neuronal structure through distinct signaling pathways. A key discovery is the identification of aldolase A, a glycolytic enzyme and actin-binding protein, as a novel effector of Reelin signaling. Reelin induced de novo translation and mobilization of aldolase A from the actin cytoskeleton. We demonstrated that aldolase A is necessary for Reelin-mediated dendrite growth and arborization in primary murine neurons and mouse brain cortical neurons. Interestingly, the function of aldolase A in dendrite development is independent of its known role in glycolysis. Altogether, our findings provide new insights into the Reelin-dependent signaling pathways and effector proteins that are crucial for dendritic development. [ABSTRACT FROM AUTHOR]

Recycling cascades combining aldolases and transaminases from biodiversity were designed for the stereoselective synthesis of various isomers of γ‐hydroxy‐α‐amino acids. Aldolases with opposite enantioselectivities were combined with a d‐α‐transaminase to prepare in a single step, d‐syn or d‐anti‐4‐hydroxyglutamic acid with high yield and stereoselectivity. Bioactive (2S,3R,4S)‐4‐hydroxy‐isoleucine was also efficiently prepared via an aldolase‐transaminase recycling cascade. In that case, the unexpected high stereoselectivity was shown to result from the thermodynamically‐driven formation of a stable derivative of the product. This novel approach was applied to the synthesis of l‐syn and d‐syn‐4‐hydroxynorvaline as well as for 3 new β‐branched‐γ‐hydroxy‐α‐amino acids, analogues of 4‐hydroxyisoleucine. [ABSTRACT FROM AUTHOR]

Prior studies have emphasized a bioenergetic crisis in the retinal pigment epithelium (RPE) as a critical factor in the development of age-related macular degeneration (AMD). The isoforms Fructose-1,6-bisphosphate aldolase C (ALDOC) and pyruvate kinase M2 (PKM2) have been proposed to play a role in AMD pathogenesis. While PKM2 and ALDOC are crucial for aerobic glycolysis in the neural retina, they are not as essential for the RPE. In this study, we examined the expression and activity of PKM2 and ALDOC in both young and aged RPE cells, as well as in the retina and RPE tissue of mice, including an experimentally induced AMD mouse model. Our findings reveal an upregulation in PKM2 and ALDOC expression, accompanied by increased pyruvate kinase activity, in the aged and AMD mouse RPE. Conversely, there is a decrease in ALDOC expression but an increase in PKM2 expression and pyruvate kinase activity in the aged and AMD retina. Overall, our study indicates that aged and AMD RPE cells tend to favor aerobic glycolysis, while this tendency is diminished in the aged and AMD retina. These results underscore the significance of targeting PKM2 and ALDOC in the RPE as a promising therapeutic approach to address the bioenergetic crisis and prevent vision loss in AMD. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to identify useful clinical indicators for predicting the relapse of interstitial lung disease (ILD) complicated with anti-aminoacyltRNA synthetase (ARS) antibodies (anti-ARS-ILD), being treated with prednisolone and calcineurin inhibitors. Methods: Fifty patients with anti-ARS-ILD were enrolled between October 2014 and August 2022. All patients were treated with prednisolone and calcineurin inhibitors as remission induction therapy and followed up for over a year with these combination therapies. We examined patients who experienced ILD relapse after immunosuppressive treatment. We explored the risk factors for predicting ILD relapse in these patients by comparing demographic, clinical, laboratory, and radiological findings and treatments between the relapsed and non-relapsed groups on admission. Results: Of the 50 patients, 19 (38%) relapsed during a median follow-up of 4.8 years. Univariate and multivariate Cox regression analyses identified the presence of acute/subacute (A/S)-ILD, higher serum aldolase (ALD) and surfactant protein-D (SP-D) levels, and lower %forced vital capacity (FVC) as risk factors for relapse in patients with anti-ARS-ILD. Using the receiver operating curve analysis, ALD =6.3 U/L, SP-D =207 ng/mL, and %FVC =76.8% were determined as the cut-off levels for indicating a poor prognosis. The 5-year relapse rate was significantly higher in patients with A/S-ILD, serum ALD=6.3 U/L, serum SP-D =207 ng/mL, or %FVC of =76.8% than in those without these parameters. (P=0.009, 0.0005, 0.0007, 0.0004, respectively) Serum ALD levels were significantly correlated with the disease activity indicators of anti-ARS-ILD. Conclusion: The presence of A/S-ILD, higher serum ALD and SP-D levels, and lower %FVC are useful indicators for predicting anti-ARS-ILD relapse. [ABSTRACT FROM AUTHOR]

Aim: To investigate the outcomes of cabozantinib in patients with unresectable hepatocellular carcinoma (uHCC), focusing on dose setting and modification. Methods: We retrospectively analyzed 34 Japanese patients who received cabozantinib for uHCC. Trough concentrations (Ctrough) of cabozantinib were also measured weekly for 6 weeks in the 18 patients. Results: Sixteen patients received ≥40 mg (high‐dose group), and 18 patients received 20 mg (low‐dose group). Dose escalations were performed in 27.8% of the patients in the low‐dose group. Although median duration of the first dose reduction or interruption in the low‐dose group was twice that in the high‐dose group (28 vs. 14 days, p < 0.001), there were no significant differences in the relative dose intensity (RDI) during 6 weeks, progression free survival (PFS), and overall survival (p = 0.162, p = 0.950, p = 0.817, respectively) between the two groups. Patients who received RDI during 6 weeks ≥33.4% showed a trend toward longer median PFS (p = 0.054). Each serum aldolase value during the 6 weeks was significantly correlated with the Ctrough at any point (r = 0.500, p < 0.001). In multivariate analyses, aldolase ≥8.7 U/L within 2 weeks was significantly associated with the very early dose reduction or interruption (odds ratio 20.0, p = 0.002). Conclusions: An initial dose of 20 mg cabozantinib could be a safe option in Japanese patients. The serum aldolase value could be useful for making appropriate dose modifications of cabozantinib. [ABSTRACT FROM AUTHOR]

Aldolase enzymes, particularly ALDOA, ALDOB, and ALDOC, play a crucial role in the development and progression of cancer. While the aldolase family is mainly known for its involvement in the glycolysis pathway, these enzymes also have various pathological and physiological functions through distinct signaling pathways such as Wnt/β-catenin, EGFR/MAPK, Akt, and HIF-1α. This has garnered increased attention in recent years and shed light on other sides of this enzyme. Potential therapeutic strategies targeting aldolases include using siRNA, inhibitors like naphthol AS-E phosphate and TX-2098, and natural compounds such as HDPS-4II and L-carnosine. Additionally, anticancer peptides derived from ALDOA, like P04, can potentially increase cancer cells' sensitivity to chemotherapy. Aldolases also affect cancer drug resistance by different approaches, making them good therapeutic targets. In this review, we extensively explore the role of aldolase enzymes in various types of cancers in proliferation, invasion, migration, and drug resistance; we also significantly explore the possible treatment considering aldolase function. [ABSTRACT FROM AUTHOR]

ObjectivesSpecial aerial gymnastics instruments (SAGI) are permanent elements of specialist training for cadet pilots. Appropriate physical activity and fitness are essential for performing the tasks of military pilots. Therefore, one of the main goals of cadet training is to develop adaptation to the extreme conditions of a military pilot’s work. This study aimed to determine the effect of the SAGI training process for cadet pilots on their aldolase and lactate dehydrogenase (LDH) activity, LDH enzymatic index (iZO), C-reactive protein (CRP) and haptoglobin (HP) levels, and physical fitness.Material and MethodsParticipating in this study were 55 cadets, aged 20 ± 0.70 years, in two groups. In group A (n = 41, tested) cadets were trained on SAGI with an emphasis on endurance and strength. In group B (n = 14, control), the cadets performed general fitness training. Blood samples were collected before and after training series I, II, and III. LDH and its isoenzyme activity, aldolase, CRP, and HP levels were assayed in blood serum using commercially available tests, and the iZO value was calculated.ResultsA downward trend was observed in HP and CRP levels in both groups after all three training series. In group A after training, LDH and aldolase activity was lower than in group B. However, in both groups, a significant increase of iZO values was observed after training series II and III in group A, p < 0.001, p < 0.05, respectively, and in group B, p < 0.05 and p < 0.0005, respectively. Physical fitness also improved in both groups.ConclusionThe course of the SAGI exercises showed that the iZO value depends on physical exercise intensity, its type, and cadet adaptation.

Rhamnulose‐1‐phosphate aldolases (RhuA) were the first dihydroxyacetone phosphate (DHAP) aldolases to be demonstrated to efficiently accept a ketone as the electrophile, providing the highly sought‐after chiral tertiary alcohol motif. It has also been found that this enzyme family can use dioxygen as an electrophile, forcing to work under inert atmosphere conditions when the target electrophile is poorly reactive. However, these features have not been explored in all DHAP‐aldolase families. Here, we present a study of E. coli K12 fuculose‐1‐phosphate‐ (FucAK12), fructose‐1,6‐bisphosphate‐ (FruAK12) and tagatose‐1,6‐bisphosphate (TagAK12) aldolases. For the latter two enzymes, this was made possible by the development of a triose phosphate isomerase (TPI)‐deleted E coli strain, which prevents DHAP isomerization into d‐glyceraldehyde 3‐phosphate (G3P), its natural electrophile. Like RhuA, TagAK12 was found to be able to oxidize DHAP into hydroxypyruvaldehyde phosphate under dioxygen, leading to the corresponding diulose. On the other hand, FucAK12 was revealed to be capable of converting ketone electrophiles with greater stereoselectivity than RhuA, and without the requirement of an inert atmosphere, since it was unable to oxidize DHAP. Finally, FruAK12 proved unable either to oxidize DHAP and or to accept ketones as electrophiles. [ABSTRACT FROM AUTHOR]

Meroterpenoids of the ochraceopones family featuring a linear tetracyclic scaffold exhibit exceptional antiviral and anti‐inflammatory activities. The biosynthetic pathway and chemical logic to generate this linear tetracycle, however, remain unknown. In this study, we identified and characterized all biosynthetic enzymes to afford ochraceopones and elucidated the complete biosynthetic pathway. We demonstrated that the linear tetracyclic scaffold of ochraceopones was derived from an angular tetracyclic precursor. A multifunctional cytochrome P450 OchH was validated to catalyze the free‐radical‐initiated carbon‐carbon bond cleavage of the angular tetracycle. Then, a new carbon‐carbon bond was verified to be constructed using a new aldolase OchL, which catalyzes an intramolecular aldol reaction to form the linear tetracycle. This carbon‐carbon bond fragmentation and aldol reaction cascade features an unprecedented strategy for converting a common angular tetracycle to a distinctive linear tetracyclic scaffold in meroterpenoid biosynthesis. [ABSTRACT FROM AUTHOR]

Abstract Aim To investigate the outcomes of cabozantinib in patients with unresectable hepatocellular carcinoma (uHCC), focusing on dose setting and modification. Methods We retrospectively analyzed 34 Japanese patients who received cabozantinib for uHCC. Trough concentrations (Ctrough) of cabozantinib were also measured weekly for 6 weeks in the 18 patients. Results Sixteen patients received ≥40 mg (high‐dose group), and 18 patients received 20 mg (low‐dose group). Dose escalations were performed in 27.8% of the patients in the low‐dose group. Although median duration of the first dose reduction or interruption in the low‐dose group was twice that in the high‐dose group (28 vs. 14 days, p

The employment of 2-deoxyribose-5-phosphate aldolase (DERA) stands as a prevalent biocatalytic route for synthesizing statin side chains. The main problem with this pathway is the low stability of the enzyme. In this study, mesocellular silica foam (MCF) with different pore sizes was used as a carrier for the covalent immobilization of DERA. Different functionalizing and activating agents were tested and kinetic modeling was subsequently performed. The use of succinic anhydride as an activating agent resulted in an enzyme hyperactivation of approx. 140%, and the stability almost doubled compared to that of the free enzyme. It was also shown that the pore size of MCF has a decisive influence on the stability of the DERA enzyme. [ABSTRACT FROM AUTHOR]

The utilization of chemical reactions is crucial in various industrial processes, including pharmaceutical synthesis and the production of fine chemicals. However, traditional chemical catalysts often lack selectivity, require harsh reaction conditions, and lead to the generation of hazardous waste. In response, biocatalysis has emerged as a promising approach within green chemistry, employing enzymes as catalysts. Among these enzymes, aldolases have gained attention for their efficiency and selectivity in catalyzing C-C bond formation, making them versatile biocatalysts for diverse biotechnological applications. Despite their potential, challenges exist in aldolase-based biocatalysis, such as limited availability of natural aldolases with desired catalytic properties. This review explores strategies to address these challenges, including immobilization techniques, recombinant expression, and protein engineering approaches. By providing valuable insights into the suitability of aldolases as biocatalysts, this review lays the groundwork for future research and the exploration of innovative strategies to fully harness the potential of aldolases in biotechnology. This comprehensive review aims to attract readers by providing a comprehensive overview of aldolase-based biocatalysis, addressing challenges, and proposing avenues for future research and development. [ABSTRACT FROM AUTHOR]

Over the past few years, it is observed an increased interest for oleaginous microorganisms in the perspective to produce microbial oils of great commercial interest through the consumption of low/zero cost substrates. In this paper, the physiology of the fungus Umbelopsis isabellina growing on blends of glycerol and glucose was investigated. In all experiments the fungus completely consumed glucose and produced satisfactory quantities of biomass containing reserve lipids in high percentages. However, glycerol concentration in the growth medium was negatively correlated to glucose assimilation rate, mainly during the balanced-growth phase. Nevertheless, at high initial concentrations, glycerol was partially consumed and seemed to contribute positively to the suppression of lipid degradation. Following the discovery of this complex regulatory mechanism regarding glucose and glycerol co-assimilation, the activity of three key-enzymes namely aldolase, glycerol kinase and glycerol dehydrogenase, which are implicated in glycerol and glucose assimilation, was investigated. The experiments revealed a clear preference of the fungus for glucose over glycerol. On the other hand, storage polysaccharides are degraded instead of storage lipid at the late oleaginous phase for maintenance purpose. These new biochemical features will enable the design of appropriate growth media for the co-fermentation of these two substrates by U. isabellina with the aim to maximize lipid accumulation.

Background: The current diagnostics of fish allergy lack sufficient accuracy such that more reliable tests such as component-resolved diagnosis (CRD) are urgently needed. This study aimed at identifying fish allergens of salmon and grass carp and evaluating the sensitization pattern in fish allergic subjects from two distinct populations in Asia. Methods: One hundred and three fish allergic subjects were recruited from Hong Kong (67 subjects) and Japan (46 subjects). Western blot and mass spectrometry were used to identify allergens from salmon and grass carp. Fish allergens were purified and tested against 96 sera on ELISA to analyze patients’ sensitization pattern. The protein profiles of salmon meat prepared under different cooking methods until core temperature reached 80 °C were evaluated by SDS-PAGE and mass spectrometry. Results: Three common allergens between salmon and grass carp, namely enolase, glycerldehyde-3-phosphate dehydrogenase (GAPDH) and parvalbumin, and two salmon-specific allergens collagen and aldolase were identified. Parvalbumin was the major allergen for both fishes showing an overall sensitization rate of 74.7%, followed by collagen (38.9%), aldolase (38.5%) and enolase (17.8%). Japanese subjects showed more diverse allergen sensitization pattern and more frequent IgE-binding to heat-labile salmon allergens. Compared with steaming and boiling, cooking by baking and frying retained more fish proteins inclusive of heat-labile allergens. Conclusions: Fish allergic patients from different Asian populations show varying fish allergen sensitization profiles. The relevant extracts and components for diagnosis are population-dependent but parvalbumin and collagen are important biomarkers. Cooking methods modify allergen composition of salmon and appear to influence patients’ allergic manifestations.

Abstract Background Alzheimer’s disease (AD) cerebrospinal fluid (CSF) core biomarkers (Aβ42/40 ratio, p-tau, and t-tau) provide high diagnostic accuracy, even at the earliest stage of disease. However, these markers do not fully reflect the complex AD pathophysiology. Recent large scale CSF proteomic studies revealed several new AD candidate biomarkers related to metabolic pathways. In this study we measured the CSF levels of four metabolism-related proteins not directly linked to amyloid- and tau-pathways (i.e., pyruvate kinase, PKM; aldolase, ALDO; ubiquitin C-terminal hydrolase L1, UCHL1, and fatty acid-binding protein 3, FABP3) across the AD continuum. We aimed at validating the potential value of these proteins as new CSF biomarkers for AD and their possible involvement in AD pathogenesis, with specific interest on the preclinical phase of the disease. Methods CSF PKM and ALDO activities were measured with specific enzyme assays while UCHL1 and FABP3 levels were measured with immunoassays in a cohort of patients composed as follows: preclinical AD (pre-AD, n = 19, cognitively unimpaired), mild cognitive impairment due to AD (MCI-AD, n = 50), dementia due to AD (ADdem, n = 45), and patients with frontotemporal dementia (FTD, n = 37). Individuals with MCI not due to AD (MCI, n = 30) and subjective cognitive decline (SCD, n = 52) with negative CSF AD-profile, were enrolled as control groups. Results CSF UCHL1 and FABP3 levels, and PKM activity were significantly increased in AD patients, already at the pre-clinical stage. CSF PKM activity was also increased in FTD patients compared with control groups, being similar between AD and FTD patients. No difference was found in ALDO activity among the groups. UCHL1 showed good performance in discriminating early AD patients (pre-AD and MCI-AD) from controls (AUC ~ 0.83), as assessed by ROC analysis. Similar results were obtained for FABP3. Conversely, PKM provided the best performance when comparing FTD vs. MCI (AUC = 0.80). Combination of PKM, FABP3, and UCHL1 improved the diagnostic accuracy for the detection of patients within the AD continuum when compared with single biomarkers. Conclusions Our study confirmed the potential role of UCHL1 and FABP3 as neurodegenerative biomarkers for AD. Furthermore, our results validated the increase of PKM activity in CSF of AD patients, already at the preclinical phase of the disease. Increased PKM activity was observed also in FTD patients, possibly underlining similar alterations in energy metabolism in AD and FTD.

Xu and colleagues recently revealed the critical role of Cryptosporidium 's feeder organelle in nutrient uptake, showcasing the parasite's ability to harness glucose and glucose-6-phosphate from host cells. This illuminates the sophisticated energy metabolism and survival strategies of the parasite, highlighting potential therapeutic targets. [ABSTRACT FROM AUTHOR]

Purpose: In our previous study, we constructed a one-pot multi-enzyme system for rare ketoses synthesis based on L-rhamnulose-1-phosphate aldolase (RhaD) from accessible glycerol in vitro. To eliminate tedious purification of enzymes, a facile Escherichia coli whole-cell cascade platform was established in this study. Methods: To enhance the conversion rate, the reaction conditions, substrate concentrations and expressions of related enzymes were extensively optimized. Results: The biosynthetic route for the cascade synthesis of rare ketoses in whole cells was successfully constructed and three rare ketoses including D-allulose, D-sorbose and L-fructose were produced using glycerol and D/L-glyceraldehyde (GA). Under optimized conditions, the conversion rates of rare ketoses were 85.0% and 93.0% using D-GA and L-GA as the receptor, respectively. Furthermore, alditol oxidase (AldO) was introduced to the whole-cell system to generate D-GA from glycerol, and the total production yield of D-sorbose and D-allulose was 8.2 g l−1 only from the sole carbon source glycerol. Conclusion: This study demonstrates a feasible and cost-efficient method for rare sugars synthesis and can also be applied to the green synthesis of other value-added chemicals from glycerol. [ABSTRACT FROM AUTHOR]

We report the first NMR and X‐ray diffraction (XRD) structures of an unusual 13/11‐helix (alternating i, i+1 {NH−O=C} and i, i+3 {C=O−H−N} H‐bonds) formed by a heteromeric 1 : 1 sequence of α‐ and δ‐amino acids, and demonstrate the application of this framework towards catalysis. Whilst intramolecular hydrogen bonds (IMHBs) are the clear driver of helix formation in this system, we also observe an apolar interaction between the ethyl residue of one δ‐amino acid and the cyclohexyl group of the next δ‐residue in the sequence that seems to stabilize one type of helix over another. To the best of our knowledge this type of additional stabilization leading to a specific helical preference has not been observed before. Critically, the helix type realized places the α‐residue functionalities in positions proximal enough to engage in bifunctional catalysis as demonstrated in the application of our system as a minimalist aldolase mimic. [ABSTRACT FROM AUTHOR]

Rare sugars possess potential applications as low-calorie sweeteners, especially for anti-obesity and anti-diabetes. In this study, a fermentation biosystem based on the "DHAP-dependent aldolases strategy" was established for D-allulose and D-sorbose production from glycerol in endotoxin-free ClearColi BL21 (DE3). Several engineering strategies were adopted to enhance rare sugar production. Firstly, the combination of different plasmids for aldO, rhaD, and yqaB expression was optimized. Then, the artificially constructed ribosomal binding site (RBS) libraries of aldO, rhaD, and yqaB genes were assembled individually and combinatorially. In addition, a peroxidase was overexpressed to eliminate the damage or toxicity from hydrogen peroxide generated by alditol oxidase (AldO). Finally, stepwise improvements in rare sugar synthesis were elevated to 15.01 g/L with a high yield of 0.75 g/g glycerol in a 3 L fermenter. This research enables the effective production of rare sugars from raw glycerol in high yields. [ABSTRACT FROM AUTHOR]

Recent advances in single-particle cryo-electron microscopy (cryo-EM) data collection utilize beam-image shift to improve throughput. Despite implementation on 300 keV cryo-EM instruments, it remains unknown how well beam-image-shift data collection affects data quality on 200 keV instruments and the extent to which aberrations can be computationally corrected. To test this, a cryo-EM data set for aldolase was collected at 200 keV using beam-image shift and analyzed. This analysis shows that the instrument beam tilt and particle motion initially limited the resolution to 4.9 Å. After particle polishing and iterative rounds of aberration correction in RELION, a 2.8 Å resolution structure could be obtained. This analysis demonstrates that software correction of microscope aberrations can provide a significant improvement in resolution at 200 keV.

Background: Alzheimer's disease (AD) cerebrospinal fluid (CSF) core biomarkers (Aβ42/40 ratio, p-tau, and t-tau) provide high diagnostic accuracy, even at the earliest stage of disease. However, these markers do not fully reflect the complex AD pathophysiology. Recent large scale CSF proteomic studies revealed several new AD candidate biomarkers related to metabolic pathways. In this study we measured the CSF levels of four metabolism-related proteins not directly linked to amyloid- and tau-pathways (i.e., pyruvate kinase, PKM; aldolase, ALDO; ubiquitin C-terminal hydrolase L1, UCHL1, and fatty acid-binding protein 3, FABP3) across the AD continuum. We aimed at validating the potential value of these proteins as new CSF biomarkers for AD and their possible involvement in AD pathogenesis, with specific interest on the preclinical phase of the disease. Methods: CSF PKM and ALDO activities were measured with specific enzyme assays while UCHL1 and FABP3 levels were measured with immunoassays in a cohort of patients composed as follows: preclinical AD (pre-AD, n = 19, cognitively unimpaired), mild cognitive impairment due to AD (MCI-AD, n = 50), dementia due to AD (ADdem, n = 45), and patients with frontotemporal dementia (FTD, n = 37). Individuals with MCI not due to AD (MCI, n = 30) and subjective cognitive decline (SCD, n = 52) with negative CSF AD-profile, were enrolled as control groups. Results: CSF UCHL1 and FABP3 levels, and PKM activity were significantly increased in AD patients, already at the pre-clinical stage. CSF PKM activity was also increased in FTD patients compared with control groups, being similar between AD and FTD patients. No difference was found in ALDO activity among the groups. UCHL1 showed good performance in discriminating early AD patients (pre-AD and MCI-AD) from controls (AUC ~ 0.83), as assessed by ROC analysis. Similar results were obtained for FABP3. Conversely, PKM provided the best performance when comparing FTD vs. MCI (AUC = 0.80). Combination of PKM, FABP3, and UCHL1 improved the diagnostic accuracy for the detection of patients within the AD continuum when compared with single biomarkers. Conclusions: Our study confirmed the potential role of UCHL1 and FABP3 as neurodegenerative biomarkers for AD. Furthermore, our results validated the increase of PKM activity in CSF of AD patients, already at the preclinical phase of the disease. Increased PKM activity was observed also in FTD patients, possibly underlining similar alterations in energy metabolism in AD and FTD. [ABSTRACT FROM AUTHOR]

The current diagnostics of fish allergy lack sufficient accuracy such that more reliable tests such as component-resolved diagnosis (CRD) are urgently needed. This study aimed at identifying fish allergens of salmon and grass carp and evaluating the sensitization pattern in fish allergic subjects from two distinct populations in Asia. One hundred and three fish allergic subjects were recruited from Hong Kong (67 subjects) and Japan (46 subjects). Western blot and mass spectrometry were used to identify allergens from salmon and grass carp. Fish allergens were purified and tested against 96 sera on ELISA to analyze patients' sensitization pattern. The protein profiles of salmon meat prepared under different cooking methods until core temperature reached 80 °C were evaluated by SDS-PAGE and mass spectrometry. Three common allergens between salmon and grass carp, namely enolase, glycerldehyde-3-phosphate dehydrogenase (GAPDH) and parvalbumin, and two salmon-specific allergens collagen and aldolase were identified. Parvalbumin was the major allergen for both fishes showing an overall sensitization rate of 74.7%, followed by collagen (38.9%), aldolase (38.5%) and enolase (17.8%). Japanese subjects showed more diverse allergen sensitization pattern and more frequent IgE-binding to heat-labile salmon allergens. Compared with steaming and boiling, cooking by baking and frying retained more fish proteins inclusive of heat-labile allergens. Fish allergic patients from different Asian populations show varying fish allergen sensitization profiles. The relevant extracts and components for diagnosis are population-dependent but parvalbumin and collagen are important biomarkers. Cooking methods modify allergen composition of salmon and appear to influence patients' allergic manifestations. [ABSTRACT FROM AUTHOR]

Although optical pure amino alcohols are in high demand due to their widespread applicability, they still remain challenging to synthesize, since commonly elaborated protection strategies are required. Here, a multi‐enzymatic methodology is presented that circumvents this obstacle furnishing enantioenriched 1,3‐amino alcohols out of commodity chemicals. A Type I aldolase forged the carbon backbone with an enantioenriched aldol motif, which was subsequently subjected to enzymatic transamination. A panel of 194 TAs was tested on diverse nine aldol products prepared through different nucleophiles and electrophiles. Due to the availability of (R)‐ and (S)‐selective TAs, both diastereomers of the 1,3‐amino alcohol motif were accessible. A two‐step process enabled the synthesis of the desired amino alcohols with up to three chiral centers with de up to >97 in the final products. [ABSTRACT FROM AUTHOR]

Simple Summary: Equine gastric ulcer syndrome (EGUS) is a frequent disease that considerably reduces the quality of life of horses, while also affecting their physical performance, even when the disease is subclinical. In this study, we hypothesized that two analytes, calprotectin (CALP) and aldolase, could be measured in saliva with commercially available assays and be potential biomarkers of EGUS in horses. We investigated the changes in the salivary CALP and aldolase in 131 horses divided into 5 different groups: controls (healthy horses), with equine squamous gastric disease (ESGD), with equine glandular gastric disease (EGGD), with combined ESGD and EGGD, and horses with other intestinal pathologies but clinical signs similar to EGUS. The two assays were precise and accurate, and, in both cases, they showed differences between horses with EGUS and healthy horses, but they did not show significant differences between horses with EGUS and horses with other diseases. Our data showed that CALP has a high ability to differentiate between healthy horses and horses with EGUS. Therefore, it could have potential use as a biomarker since a value of CALP in the range of healthy individuals could indicate that the animal is not likely to have EGUS at gastroscopy. Equine gastric ulcer syndrome (EGUS) is a highly prevalent disease that affects horses worldwide. Within EGUS, two different forms have been described: equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD). The associated clinical signs cause detrimental activity performance, reducing the quality of life of animals. Saliva can contain biomarkers for EGUS that could be potentially used as a complementary tool for diagnosis. The objective of this work was to evaluate the measurements of calprotectin (CALP) and aldolase in the saliva of horses as potential biomarkers of EGUS. For this purpose, automated assays for the quantification of these two proteins were analytically validated and applied for detecting EGUS in a total of 131 horses divided into 5 groups: healthy horses, ESGD, EGGD, combined ESGD and EGGD, and horses with other intestinal pathologies. The assays showed good precision and accuracy in analytical validation, and they were able to discriminate between horses with EGUS and healthy horses, especially in the case of CALP, although they did not show significant differences between horses with EGUS and horses with other diseases. In conclusion, salivary CALP and aldolase can be determined in the saliva of horses and further studies are warranted to elucidate the potential of these analytes as biomarkers in EGUS. [ABSTRACT FROM AUTHOR]

Michael addition reactions are highly useful in organic synthesis and are commonly accomplished using organocatalysts. However, the corresponding biocatalytic Michael additions are rare, typically lack synthetically useful substrate scope, and suffer from low stereoselectivity. Herein we report a biocatalytic nitro‐Michael addition, catalyzed by NahE, that proceeds with low catalyst loading at room temperature in moderate to excellent enantioselectivity and high yields. A series of β‐nitrostyrenes reacted with pyruvate in the presence of NahE to give, after oxidative decarboxylation, β‐aryl‐γ‐nitrobutyric acids in up to 99 % yield without need for chromatography, providing a simple preparative‐scale route to chiral GABA analogues. This reaction represents the first example of an aldolase displaying promiscuous Michaelase activity and opens the use of nitroalkenes in place of aldehydes as substrates for aldolases. [ABSTRACT FROM AUTHOR]

The importance of a compound that helps fight against influenza is, in times of a pandemic, self-evident. In order to produce these compounds in vast quantities, many researchers consider continuous flow reactors in chemical industry as next stepping stone for large scale production. For these reasons, the synthesis of N-acetylneuraminic acid (Neu5Ac) in a continuous fixed-bed reactor by an immobilized epimerase and aldolase was investigated in detail. The immobilized enzymes showed high stability, with half-life times > 173 days under storage conditions (6 °C in buffer) and reusability over 50 recycling steps, and were characterized regarding the reaction kinetics (initial rate) and scalability (different lab scales) in a batch reactor. The reaction kinetics were studied in a continuous flow reactor. A high-pressure circular reactor (up to 130 MPa) was applied for the investigation of changes in the position of the reaction equilibrium. By this, equilibrium conversion, selectivity, and yield were increased from 57.9% to 63.9%, 81.9% to 84.7%, and 47.5% to 54.1%, respectively. This indicates a reduction in molar volume from N-acetyl-ᴅ-glucosamine (GlcNAc) and pyruvate (Pyr) to Neu5Ac. In particular, the circular reactor showed great potential to study reactions at high pressure while allowing for easy sampling. Additionally, an increase in affinity of pyruvate towards both tested enzymes was observed when high pressure was applied, as evidenced by a decrease of KI for the epimerase and KM for the aldolase from 108 to 42 mM and 91 to 37 mM, respectively.

• MADD is clinically heterogeneous and can involve distal musculature with asymmetry. • MADD can present with isolated aldolase elevation in the setting of normal CK. • Elevated growth differentiation factor 15 in MADD suggests mitochondrial dysfunction. • Very late onset MADD can robustly respond to oral riboflavin. A 72-year-old woman on sertraline and levothyroxine (Levoxyl) presented to clinic with progressive proximal > distal and left > right upper and lower extremity weakness. She had length-dependent paresthesias and sensory deficits. Aldolase was elevated but CK was normal. EMG/NCS showed myopathic motor units. Muscle biopsy revealed numerous muscle fibers with markedly increased lipid content. Additional bloodwork showed elevated plasma acylcarnitine species of all chain lengths, concerning for multiple acyl-CoA dehydrogenase deficiency (MADD), along with elevated Growth Differentiation Factor 15 (GDF-15). Metabolic and mitochondrial genetic testing followed by whole exome sequencing was negative. The patient started riboflavin 400 mg daily and improved from requiring a wheelchair to independent ambulation. She was diagnosed with very-late-onset riboflavin-responsive MADD. This case adds to the growing literature on the clinical heterogeneity of VLO-MADD, comments on the potential for non-genetic, pharmacologic triggers like sertraline, and highlights that GDF-15 and aldolase can be elevated with normal CK. [ABSTRACT FROM AUTHOR]

According to evolutionary theory, many naturally-occurring amino acid substitutions are expected to be neutral or near-neutral, with little effect on protein structure or function. Accordingly, most changes observed in human exomes are also expected to be neutral. As such, accurate algorithms for identifying medically-relevant changes must discriminate rare, non-neutral substitutions against a background of neutral substitutions. However, due to historical biases in biochemical experiments, the data available to train and validate prediction algorithms mostly contains non-neutral substitutions, with few examples of neutral substitutions. Thus, available training sets have the opposite composition of the desired test sets. Towards improving a dataset of these critical negative controls, we have concentrated on identifying neutral positions – those positions for which most of the possible 19 amino acid substitutions have little effect on protein structure or function. Here, we used a strategy based on multiple sequence alignments to identify putative neutral positions in human aldolase A, followed by biochemical assays for 147 aldolase substitutions. Results showed that most variants had little effect on either the apparent Michaelis constant for substrate fructose-1,6-bisphosphate or its apparent cooperativity. Thus, these data are useful for training and validating prediction algorithms. In addition, we created a database of these and other biochemically characterized aldolase variants along with aldolase sequences and characteristics derived from sequence and structure analyses. This database is publicly available at https://github.com/liskinsk/Aldolase-variant-and-sequence-database. [Display omitted] • Any two human exomes can differ by up to 10,000 amino acid changes. • Rare, medically-relevant changes are embedded in a background of neutral changes. • Improving computer detection requires more examples of biochemically neutral changes. • We identified changes in human aldolase A that are neutral for substrate binding. • A database of other published human aldolase variants is included. [ABSTRACT FROM AUTHOR]

ABSTRACT The preferred carbon source of Staphylococcus aureus and many other pathogens is glucose, and its consumption is critical during infection. However, glucose utilization increases the cellular demand for manganese, a nutrient sequestered by the host as a defense against invading pathogens. Therefore, bacteria must balance glucose metabolism with the increasing demand that metal-dependent processes, such as glycolysis, impose upon the cell. A critical regulator that enables S. aureus to resist nutritional immunity is the ArlRS two-component system. This work revealed that ArlRS regulates the expression of FdaB, a metal-independent fructose 1,6-bisphosphate aldolase. Further investigation revealed that when S. aureus is metal-starved by the host, FdaB functionally replaces the metal-dependent isozyme FbaA, thereby allowing S. aureus to resist host-imposed metal starvation in culture. Although metal-dependent aldolases are canonically zinc-dependent, this work uncovered that FbaA requires manganese for activity and that FdaB protects S. aureus from manganese starvation. Both FbaA and FdaB contribute to the ability of S. aureus to cause invasive disease in wild-type mice. However, the virulence defect of a strain lacking FdaB was reversed in calprotectin-deficient mice, which have defects in manganese sequestration, indicating that this isozyme contributes to the ability of this pathogen to overcome manganese limitation during infection. Cumulatively, these observations suggest that the expression of the metal-independent aldolase FdaB allows S. aureus to alleviate the increased demand for manganese that glucose consumption imposes, and highlights the cofactor flexibility of even established metalloenzyme families. IMPORTANCE Staphylococcus aureus and other pathogens consume glucose during infection. Glucose utilization increases the demand for transition metals, such as manganese, a nutrient that the host limits as a defense mechanism against invading pathogens. Therefore, pathogenic bacteria must balance glucose and manganese requirements during infection. The two-component system ArlRS is an important regulator that allows S. aureus to adapt to both glucose and manganese starvation. Among the genes regulated by ArlRS is the metal-independent fructose 1,6-bisphosphate aldolase fdaB, which functionally substitutes for the metal-dependent isoenzyme FbaA and enables S. aureus to survive host-imposed manganese starvation. Unexpectedly, and differing from most characterized metal-dependent aldolases, FbaA requires manganese for activity. Cumulatively, these findings reveal a new mechanism for overcoming nutritional immunity as well as the cofactor plasticity of even well-characterized metalloenzyme families.

Type I aldolases catalyze carbon–carbon bond-forming reactions to form a diverse set of products in nature but often display high selectivity for their natural substrates. One such aldolase, NahE, is known to catalyze the condensation of pyruvate with a wide range of aldehydes to give trans -4-phenyl-2-oxo-3-butenoic acids under mild aqueous conditions. These α,β-unsaturated 2-oxo acids are versatile intermediates for synthetic transformations. NahE has also been used for the synthesis of α-fluoro-β-hydroxy esters, β-hydroxy esters, and quinaldic acids. However, a thorough study of the substrate scope on a practical scale has not been performed for the native NahE-catalyzed aldol condensation reaction. Here we report that NahE can accept >35 (hetero)aromatic and aliphatic aldehydes. Most condensation products derived from substituted benzaldehydes were isolated in >95% yield without need for further purification, while non-benzaldehyde substrates gave the corresponding products in isolated yields between 26% and 98%. Reactions could be performed on gram scale. These products could be converted into α,β-unsaturated carboxylic acids in up to 93% yield over two steps. This reaction sequence was also performed using whole cells in up to 79% yield. This work demonstrates that NahE is a robust, efficient, and versatile catalyst for organic synthesis. [ABSTRACT FROM AUTHOR]

Platform chemicals and polymer precursors can be produced via enzymatic pathways starting from lignocellulosic waste materials. The hemicellulose fraction of lignocellulose contains aldopentose sugars, such as d-xylose and l-arabinose, which can be enzymatically converted into various biobased products by microbial non-phosphorylated oxidative pathways. The Weimberg and Dahms pathways convert pentose sugars into α-ketoglutarate, or pyruvate and glycolaldehyde, respectively, which then serve as precursors for further conversion into a wide range of industrial products. In this review, we summarize the known three-dimensional structures of the enzymes involved in oxidative non-phosphorylative pathways of pentose catabolism. Key structural features and reaction mechanisms of a diverse set of enzymes responsible for the catalytic steps in the reactions are analysed and discussed. [ABSTRACT FROM AUTHOR]

Aldolases are crucial enzymes that catalyze the formation of carbon-carbon bonds in the context of the anabolic and catabolic pathways of various metabolites. The bacterium Pseudomonas fluorescens N3 can use naphthalene as its sole carbon and energy source by using, among other enzymes, the trans-o-hydroxybenzylidenepyruvate (tHBP) hydratase-aldolase (HA), encoded by the nahE gene. In this study, we present the crystallographic structures of tHBP-HA in three different functional states: the apo enzyme with a phosphate ion in the active site, and the Schiff base adduct bound either to pyruvate or to the substitute with '(R)-4-hydroxy-4-(2-hydroxyphenyl)-2-oxobutanoate'(intermediate state). Our structures elucidate some of the phases of the aldol condensation reaction, proposing the role of a conserved water molecule (W2) in the deprotonation of the catalytic lysine. Moreover, our crystallographic data suggest potential pathways for substrate and product diffusion to and from the protein's active site. These insights advance our understanding of the molecular mechanisms of the aldolase function and can also be used for the design and optimization of new enzymes engineered for the chemical synthesis of different C-C adducts., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mario Milani reports administrative support and equipment, drugs, or supplies were provided by European Union. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

Lysyl-oxidase like-2 (LOXL2) regulates extracellular matrix remodeling and promotes tumor invasion and metastasis. Altered metabolism is a core hallmark of cancer, however, it remains unclear whether and how LOXL2 contributes to tumor metabolism. Here, we found that LOXL2 and its catalytically inactive L2Δ13 splice variant boost glucose metabolism of esophageal tumor cells, facilitate tumor cell proliferation and promote tumor development in vivo. Consistently, integrated transcriptomic and metabolomic analysis of a knock-in mouse model expressing L2Δ13 gene revealed that LOXL2/L2Δ13 overexpression perturbs glucose and lipid metabolism. Mechanistically, we identified aldolase A, glyceraldehyde-3-phosphate dehydrogenase and enolase as glycolytic proteins that interact physically with LOXL2 and L2Δ13. In the case of aldolase A, LOXL2/L2Δ13 stimulated its mobilization from the actin cytoskeleton to enhance aldolase activity during malignant transformation. Using stable isotope labeling of amino acids in cell culture (SILAC) followed by proteomic analysis, we identified LOXL2 and L2Δ13 as novel deacetylases that trigger metabolic reprogramming. Both LOXL2 and L2Δ13 directly catalyzed the deacetylation of aldolase A at K13, resulting in enhanced glycolysis which subsequently reprogramed tumor metabolism and promoted tumor progression. High level expression of LOXL2/L2Δ13 combined with decreased acetylation of aldolase-K13 predicted poor clinical outcome in patients with esophageal cancer. In summary, we have characterized a novel molecular mechanism that mediates the pro-tumorigenic activity of LOXL2 independently of its classical amine oxidase activity. These findings may enable the future development of therapeutic agents targeting the metabolic machinery via LOXL2 or L2Δ13. Highlight of the study: LOXL2 and its catalytically inactive isoform L2Δ13 function as new deacetylases to promote metabolic reprogramming and tumor progression in esophageal cancer by directly activating glycolytic enzymes such as aldolase A.

Rare sugars possess potential applications as low-calorie sweeteners, especially for anti-obesity and anti-diabetes. In this study, a fermentation biosystem based on the “DHAP-dependent aldolases strategy” was established for D-allulose and D-sorbose production from glycerol in endotoxin-free ClearColi BL21 (DE3). Several engineering strategies were adopted to enhance rare sugar production. Firstly, the combination of different plasmids for aldO, rhaD, and yqaB expression was optimized. Then, the artificially constructed ribosomal binding site (RBS) libraries of aldO, rhaD, and yqaB genes were assembled individually and combinatorially. In addition, a peroxidase was overexpressed to eliminate the damage or toxicity from hydrogen peroxide generated by alditol oxidase (AldO). Finally, stepwise improvements in rare sugar synthesis were elevated to 15.01 g/L with a high yield of 0.75 g/g glycerol in a 3 L fermenter. This research enables the effective production of rare sugars from raw glycerol in high yields.

Enzyme immobilization is a technology that enables (bio-)catalysts to be applied in continuous-flow systems. However, there is a plethora of immobilization methods available with individual advantages and disadvantages. Here, we assessed the influence of simple and readily available methods with respect to the performance of 2-deoxy-d-ribose-5-phosphate aldolase (DERA) in continuous-flow conditions. The investigated immobilization strategies cover the unspecific attachment to carriers via epoxides, affinity-based attachment via metal ion affinity, StrepTag™-StrepTactin™ interaction as well as the covalent affinity attachment of an enzyme to a matrix tethered by the HaloTag®. The metal-ion-affinity-based approach outperformed the other methods in terms of immobilized activity and stability under applied conditions. As most enzymes examined today already have a HisTag for purification purposes, effective immobilization may be applied, as simple as a standard purification, if needed. [ABSTRACT FROM AUTHOR]

• Diagnosis of fish may represent an important challenge for the allergists. • There is not a complete cross reactivity among different ß-parvalbumins. • Comprehensive panel of fish allergens is useful for the diagnosis of allergy. Diagnosis of fish may represent an important challenge for the allergists. This study aimed to evaluate the diagnostic sensitivity of an in vitro multiplex assay using a comprehensive panel of fish allergens and the cross-reactivity patterns between different molecular components. 56 subjects with fish allergy were enrolled. All patients underwent specific IgE measurement using the Allergy Explorer-Alex 2™ multiplex assay (Macroarray Diagnostics, Vienna, Austria) The single ß-parvalbumins Clu h 1, Cyp c 1, Gad m 1, Sal s 1, Sco s 1, Thu a 1 and Xyp g 1 scored positive in 75.0%, 67.8%, 62.5%, 80.3%,80.3%, 78.8% and 73,2% patients, respectively. 14.3% scored positive for the α-parvalbumin (Raj c-parvalbumin), and 16.1% for the aldolase + enolase (Gad m 2 + 3) components. 92.8% reacted to at least one ß-parvalbumin and 96.4% to at least one of the allergens tested. Overall sensitivity was higher than that obtained using commercial extracts of cod, salmon and tuna for skin prick test (75.8%) and IgE detection (92.3%). The Alex 2 showed high diagnostic sensitivity and it might be used as an additional assay to investigate the cross-reactivity patterns between different molecular components, looking for potentially safe fish species. [ABSTRACT FROM AUTHOR]

Background: These studies examined mutual protective relationships among rabbit muscle aldolase, enolase, phosphofructokinase-1 (PFK-1) and LDH from inhibitions by ascorbate (AA). It was proposed earlier that specific inhibitions of PFK-1 and LDH by AA faciltated glycogen storage in resting muscle by inhibiting glycolysis. Materials and Methods: The L-ascorbate (AA), L-ascorbyl dibutyrate (AADB), L-ascorbyl dipalmitate (AADP), L-ascorbyl palmitate (AAP), and L-ascorbyl stearate (AS) are shown in Figure 1 and were obtained from TCI and Alfa Aesar. Unless otherwise stated, all enzymes come from rabbit and all experimental temperatures were 25°C, pH 8.0. Results: Rabbit muscle enolase was examined for its protective effect on other rabbit muscle glycolytic enzymes against inhibitions by ascorbate (AA) and some AA-faty acid derivatives. The IC50 values of enolase by ascorbate (AA) and IC50 values of AA-fatty acid derivatives were compared to estimate inhibition potency. For example, ascorbyl dipalmitate (AADP) was 156 times more inhibitory to enolase than AA. It was previously shown that rabbit muscle aldolase prevented LDH activity loses due to AA inhibition and prevented PFK-1 activity losses due both to dilution and AA inhibition; enolase was found to have the same effects as aldolase. Additionally, PFK-1 prevented enolase and LDH inhibitions by AA. LDH did not prevent enolase or PFK-1 from inhibition by AA. LDH did stimulate enolase activity but not PFK-1 activity. Conclusion: The results suggest that interactions among glycolytic enzyme serve to mutually protect one another from activity losses. The inhibition properties of the AA-fatty acid derivatives are discussed in relation to their possible roles in cancer and diabetes. [ABSTRACT FROM AUTHOR]

Background: Previous studies suggested that glycogen storage was facilitated by ascorbate inhibition of phosphofructokinase-1 (PFK-1) in resting mammalian muscle; these studies showed that purified PFK-1 from fish or chicken muscle has properties similar to PFK-1 from mammalian muscles. Materials and Methods: The enzymes utilized in the assay systems came from Sigma-Aldrich Co. Rabbit (Oryctolagus cuniculus) muscle G-actin (A 2522) was free of aldolase, LDH (EC 1.1.1.28) or AK (EC 2.7.4.3) activity and rabbit muscle aldolase (EC 4.1.2.13) was free of AK (EC 2.7.4.3) and LDH activity. Rabbit muscle PFK-1 (RPFK-1), chicken (Gallus gallus) muscle PFK-1 (CPFK-1) and Pacific red snapper (Lutjanus peru) muscle PFK-1 (FPFK-1) used in these tests were prepared from frozen tissues with modifications of a method. AK, LDH, and aldolase activity were absent in purified FPFK-1 and CPFK-1 preparations. Results: It can be shown that the following enzymes associated with glycolysis are not inhibited by 0.1 M ascorbate under our conditions: rabbit muscle aldolase (EC 4.1.2.13); rabbit muscle glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.12); rabbit muscle phosphoglucose isomerase (EC 5.3.1.9); rabbit muscle pyruvate kinase (EC 2.7.1.40); yeast hexokinase (EC 2,7.1.1); and yeast 3-phosphoglyceric phosphokinase (EC 2.7.2.3). Rabbit muscle enolase (EC4.2.1.11) is inhibited under our conditions. Conclusion: In summary, FPFK-1 and CPFK-1, possess characteristics and behaviors similar to RPFK-1, e.g., losses of activities due to dilutions and protections of some of these activity losses by rabbit muscle aldolase. These interactions of a mammalian aldolase with fish and a bird PFK-1's suggests a conservative evolutionary relationship among aldolases and PFK-1's. [ABSTRACT FROM AUTHOR]

Patulin is a mycotoxin produced by Penicillium species that can cause severe food safety concerns. Biological enzymes are considered one of the promising methods for degrading patulin. The purpose of this study was focused on isolating and purifying Aldolase from Rhodotorula mucilaginosa. The results showed that the molecular weight of purified Aldolase was 36 kDa. The Aldolase had an optimal pH 7.0 and was stable at a pH range of 5.5–7.0. The optimum temperature for Aldolase was 25 °C and exhibited thermostability in the range of 4–25 °C. The Aldolase activity was induced moderately by Ca2+, Cu2+, PMSF and SDS, while Fe3+ and EDTA significantly inhibited the activity. The kinetic parameters (K m and V max) for Aldolase were 109.46 mM and 4.34 mM/h, respectively. When 0.7 mg/mL of Aldolase was added, 2 mg/L of patulin in apple juice can be degraded. Moreover, there is no significant difference in the quality parameters and volatile compounds before and after degradation in apple juice. Finally, the Aldolase gene was successfully cloned and expressed in E. coli. Meanwhile, the purified cloned Aldolase has an excellent patulin degradation ratio of more than 99% (15 mg/L). These findings suggested that Aldolase was a promising material for patulin degradation. [Display omitted] • Aldolase has been isolated and identified from Rhodotorula mucilaginosa. • Adding 0.7 mg/mL Aldolase could reduce 2 mg/L patulin at 25 °C for 36 h. • The degradation process of Aldolase has no deterioration on quality of apple juice. • Aldolase gene was successfully cloned and expressed in Escherichia coli. [ABSTRACT FROM AUTHOR]