Amination of naringinase to improve citrus juice debittering using a catalyst immobilized on glyoxyl-agarose.

A naringinase complex was chemically aminated prior to its immobilization on glyoxyl-agarose to develop a robust biocatalyst for juice debittering. The effects of amination on the optimal pH and temperature, thermal stability, and debittering performance were analyzed. Concentration of amino groups on catalysts surface increased in 36 %. Amination reduced the ß-glucosidase activity of naringinase complex; however, did not affect optimal pH and temperature of the enzyme and it favored immobilization, obtaining α-l-rhamnosidase and ß-d-glucosidase activities of 1.7 and 4.2 times the values obtained when the unmodified enzymes were immobilized. Amination favored the stability of the immobilized biocatalyst, retaining 100 % of both activities after 190 h at 30 °C and pH 3, while its non-aminated counterpart retained 80 and 52 % of α-rhamnosidase and ß-glucosidase activities, respectively. The immobilized catalyst showed a better performance in grapefruit juice debittering, obtaining a naringin conversion of 7 times the value obtained with the non-aminated catalyst.

Venous and arterial thrombosis in patients with VEXAS syndrome.

ABSTRACT: VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, caused by somatic mutations in UBA1, is an autoinflammatory disorder with diverse systemic manifestations. Thrombosis is a prominent clinical feature of VEXAS syndrome. The risk factors and frequency of thrombosis in VEXAS syndrome are not well described, due to the disease's recent discovery and the paucity of large databases. We evaluated 119 patients with VEXAS syndrome for venous and arterial thrombosis and correlated their presence with clinical outcomes and survival. Thrombosis occurred in 49% of patients, mostly venous thromboembolism (VTE; 41%). Almost two-thirds of VTEs were unprovoked, 41% were recurrent, and 20% occurred despite anticoagulation. The cumulative incidence of VTE was 17% at 1 year from symptom onset and 40% by 5 years. Cardiac and pulmonary inflammatory manifestations were associated with time to VTE. M41L was positively associated specifically with pulmonary embolism by univariate (odds ratio [OR]: 4.58, confidence interval [CI] 1.28-16.21, P = .02) and multivariate (OR: 16.94, CI 1.99-144.3, P = .01) logistic regression. The cumulative incidence of arterial thrombosis was 6% at 1 year and 11% at 5 years. The overall survival of the entire patient cohort at median follow-up time of 4.8 years was 88%, and there was no difference in survival between patients with or without thrombosis (P = .8). Patients with VEXAS syndrome are at high risk of VTE; thromboprophylaxis should administered be in high-risk settings unless strongly contraindicated.

A Case of VEXAS: Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic Syndrome With Co-existing DNA (Cytosine-5)-Methyltransferase 3A Mutation Complicated by Localized Skin Reaction to Tocilizumab and Azacitidine.

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a recently identified autoinflammatory condition with a correlating missense somatic mutation of the X chromosome. Here we present a unique case of a patient with VEXAS syndrome with coinciding ubiquitin-like modifier activating enzyme 1 (UBA1) and DNA (cytosine-5)-methyltransferase 3A (DNMT3A) mutations who developed cutaneous and systemic reactions to tocilizumab and azacitidine therapy, respectively.

Spectrum of clonal hematopoiesis in VEXAS syndrome.

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is caused by somatic mutations in UBA1 (UBA1mut) and characterized by heterogenous systemic autoinflammation and progressive hematologic manifestations, meeting criteria for myelodysplastic syndrome (MDS) and plasma cell dyscrasias. The landscape of myeloid-related gene mutations leading to typical clonal hematopoiesis (CH) in these patients is unknown. Retrospectively, we screened 80 patients with VEXAS for CH in their peripheral blood (PB) and correlated the findings with clinical outcomes in 77 of them. UBA1mut were most common at hot spot p.M41 (median variant allele frequency [VAF] = 75%). Typical CH mutations cooccurred with UBA1mut in 60% of patients, mostly in DNMT3A and TET2, and were not associated with inflammatory or hematologic manifestations. In prospective single-cell proteogenomic sequencing (scDNA), UBA1mut was the dominant clone, present mostly in branched clonal trajectories. Based on integrated bulk and scDNA analyses, clonality in VEXAS followed 2 major patterns: with either typical CH preceding UBA1mut selection in a clone (pattern 1) or occurring as an UBA1mut subclone or in independent clones (pattern 2). VAF in the PB differed markedly between DNMT3A and TET2 clones (median VAF of 25% vs 1%). DNMT3A and TET2 clones associated with hierarchies representing patterns 1 and 2, respectively. Overall survival for all patients was 60% at 10 years. Transfusion-dependent anemia, moderate thrombocytopenia, and typical CH mutations, each correlated with poor outcome. In VEXAS, UBA1mut cells are the primary cause of systemic inflammation and marrow failure, being a new molecularly defined somatic entity associated with MDS. VEXAS-associated MDS is distinct from classical MDS in its presentation and clinical course.

Industrial bioelectrochemistry for waste valorization: State of the art and challenges.

Bioelectrochemistry has gained importance in recent years for some of its applications on waste valorization, such as wastewater treatment and carbon dioxide conversion, among others. The aim of this review is to provide an updated overview of the applications of bioelectrochemical systems (BESs) for waste valorization in the industry, identifying current limitations and future perspectives of this technology. BESs are classified according to biorefinery concepts into three different categories: (i) waste to power, (ii) waste to fuel and (iii) waste to chemicals. The main issues related to the scalability of bioelectrochemical systems are discussed, such as electrode construction, the addition of redox mediators and the design parameters of the cells. Among the existing BESs, microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) stand out as the more advanced technologies in terms of implementation and R&D investment. However, there has been little transfer of such achievements to enzymatic electrochemical systems. It is necessary that enzymatic systems learn from the knowledge reached with MFC and MEC to accelerate their development to achieve competitiveness in the short term.

VEXAS syndrome: A review of bone marrow aspirate and biopsies reporting myeloid and erythroid precursor vacuolation.

Myeloid and erythroid precursor vacuolation is a common dysplastic finding associated with myeloid malignancies, toxins, drug, and nutritional deficiencies. It has been described as a core morphologic feature in VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. We sought to determine the number of cases attributable to VEXAS syndrome in bone marrow biopsies and aspirates (BAMB) reporting myeloid precursor vacuolation. We reviewed 1318 individual BAMB reports from January 2020 to July 2021 where "vacuole(s)," "vacuolation," or "vacuolated" was reported. Bone marrow biopsies with vacuolation confined to blasts or those completed as routine workup prior to stem cell transplant or post induction chemotherapy for AML (acute myeloid leukemia) were excluded. Myeloid and erythroid precursor vacuolation was noted in 219 reports representing 210 patients. The most common etiology was myelodysplastic syndrome (MDS) (38.6%), AML (16.7%), lymphoproliferative disorders and multiple myeloma (7.6%), drug or toxin exposure (5.2%) myeloproliferative neoplasm (MPN) or MPN/MDS overlap syndrome (4.3%). VEXAS syndrome was determined to be the etiology in 2.9% of patients. Two additional cases of VEXAS syndrome with bone marrow biopsies reported in the specified time frame did not explicitly report myeloid or erythroid precursor vacuolation but were identified based on clinical suspicion and repeat BAMB review. Myeloid and erythroid precursor vacuolation is a dysplastic feature attributable to VEXAS syndrome in at least 2.9% of cases. Standardized reporting of vacuolization, triaging of molecular sequencing and optimal treatment of this disorder are critical issues facing those seeing patients with suspected VEXAS syndrome.

Enzymatic Synthesis of Ascorbyl Palmitate in a Rotating Bed Reactor.

Ascorbyl palmitate, an ascorbic acid ester, is an important amphipathic antioxidant that has several applications in foods, pharmaceuticals, and cosmetics. The enzymatic synthesis of ascorbyl palmitate is very attractive, but few efforts have been made to address its process scale-up and implementation. This study aimed at evaluating the enzymatic synthesis of ascorbyl palmitate in a rotating basket reactor operated in sequential batches. Different commercial immobilized lipases were tested, and the most suitable reaction conditions were established. Among those lipases studied were Amano Lipase PS, Lipozyme® TL IM, Lipozyme® Novo 40086, Lipozyme® RM IM and Lipozyme® 435. Initially, the enzymes were screened based on previously defined synthesis conditions, showing clear differences in behavior. Lipozyme® 435 proved to be the best catalyst, reaching the highest values of initial reaction rate and yield. Therefore, it was selected for the following studies. Among the solvents assayed, 2-methyl-2-butanol and acetone showed the highest yields, but the operational stability of the catalyst was better in 2-methyl-2-butanol. The tests in a basket reactor showed great potential for large-scale application. Yields remained over 80% after four sequential batches, and the basket allowed for easy catalyst recycling. The results obtained in basket reactor are certainly a contribution to the enzymatic synthesis of ascorbyl palmitate as a competitive alternative to chemical synthesis. This may inspire future cost-effectiveness studies of the process to assess its potential as a viable alternative to be implemented.

Translation of cytoplasmic UBA1 contributes to VEXAS syndrome pathogenesis.

Somatic mutations in UBA1 cause vacuoles, E1 ubiquitin-activating enzyme, X-linked, autoinflammatory somatic (VEXAS) syndrome, an adult-onset inflammatory disease with an overlap of hematologic manifestations. VEXAS syndrome is characterized by a high mortality rate and significant clinical heterogeneity. We sought to determine independent predictors of survival in VEXAS and to understand the mechanistic basis for these factors. We analyzed 83 patients with somatic pathogenic variants in UBA1 at p.Met41 (p.Met41Leu/Thr/Val), the start codon for translation of the cytoplasmic isoform of UBA1 (UBA1b). Patients with the p.Met41Val genotype were most likely to have an undifferentiated inflammatory syndrome. Multivariate analysis showed ear chondritis was associated with increased survival, whereas transfusion dependence and the p.Met41Val variant were independently associated with decreased survival. Using in vitro models and patient-derived cells, we demonstrate that p.Met41Val variant supports less UBA1b translation than either p.Met41Leu or p.Met41Thr, providing a molecular rationale for decreased survival. In addition, we show that these 3 canonical VEXAS variants produce more UBA1b than any of the 6 other possible single-nucleotide variants within this codon. Finally, we report a patient, clinically diagnosed with VEXAS syndrome, with 2 novel mutations in UBA1 occurring in cis on the same allele. One mutation (c.121 A>T; p.Met41Leu) caused severely reduced translation of UBA1b in a reporter assay, but coexpression with the second mutation (c.119 G>C; p.Gly40Ala) rescued UBA1b levels to those of canonical mutations. We conclude that regulation of residual UBA1b translation is fundamental to the pathogenesis of VEXAS syndrome and contributes to disease prognosis.

Covalent Immobilization of Dehydrogenases on Carbon Felt for Reusable Anodes with Effective Electrochemical Cofactor Regeneration.

This study presents the immobilization with aldehyde groups (glyoxyl carbon felt) of alcohol dehydrogenase (ADH) and formate dehydrogenase (FDH) on carbon-felt-based electrodes. The compatibility of the immobilization method with the electrochemical application was studied with the ADH bioelectrode. The electrochemical regeneration process of nicotinamide adenine dinucleotide in its oxidized form (NAD+ ), on a carbon felt surface, has been deeply studied with tests performed at different electrical potentials. By applying a potential of 0.4 V versus Ag/AgCl electrode, a good compromise between NAD+ regeneration and energy consumption was observed. The effectiveness of the regeneration of NAD+ was confirmed by electrochemical oxidation of ethanol catalyzed by ADH in the presence of NADH, which is the no active form of the cofactor for this reaction. Good reusability was observed by using ADH immobilized on glyoxyl functionalized carbon felt with a residual activity higher than 60 % after 3 batches.

Grapefruit Debittering by Simultaneous Naringin Hydrolysis and Limonin Adsorption Using Naringinase Immobilized in Agarose Supports.

Naringin and limonin are the two main bitter compounds of citrus products such as grapefruit juice. The aim of this investigation was to evaluate the reduction in both bitter components simultaneously using a combined biochemical and physical approach. The proposed strategy was based on the use of heterofunctional supports with glyoxyl groups that allow for the covalent immobilization of naringinase, which hydrolyses naringin and alkyl groups that allow for the adsorption of limonin. The supports were butyl-glyoxyl agarose (BGA) and octyl-glyoxyl agarose (OGA), which were characterized in terms of aldehyde group quantification and FTIR analysis. The optimal pH and temperature of free and immobilized enzymes were assessed. The maximum enzyme loading capacity of supports was analyzed. Debittering of grapefruit juice was evaluated using soluble enzyme, enzyme-free supports, and immobilized catalysts. Enzyme immobilized in BGA reduced naringin and limonin concentrations by 54 and 100%, respectively, while the use of catalyst immobilized in OGA allowed a reduction of 74 and 76%, respectively, obtaining a final concentration of both bitter components under their detection threshold. The use of OGA biocatalyst presented better results than when soluble enzyme or enzyme-free support was utilized. Biocatalyst was successfully applied in juice debittering in five repeated batches.

A clinical, histopathological, and molecular study of two cases of VEXAS syndrome without a definitive myeloid neoplasm.

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is caused by somatic mutations in UBA1 and is identified by a genotype-driven method. This condition affects unrelated men with adultonset inflammatory syndromes in association with hematologic manifestations of peripheral cytopenia and bone marrow myeloid dysplasia. Although bone marrow vacuolization restricted to myeloid and erythroid precursors has been identified in patients with VEXAS, the detailed clinical and histopathological features of peripheral blood and bone marrows remain unclear. The current case report describes the characteristic hematologic findings in patients with VEXAS, including macrocytic anemia, thrombocytopenia, marked hypercellular bone marrow with granulocytic hyperplasia, megaloblastic changes in erythroid precursors, and the absence of hematogones in addition to prominent vacuoles in myeloid and erythroid precursor cells. Characterizing the clinical and hematologic features helps to raise awareness and improve diagnosis of this novel, rare, but potentially underrecognized disease. Prompt diagnosis expands the general knowledgeable and understanding of this disease, and optimal management may prevent patients from developing complications related to this refractory inflammatory syndrome and improve the overall clinical outcome.

Benign and malignant hematologic manifestations in patients with VEXAS syndrome due to somatic mutations in UBA1.

Somatic mutations in UBA1 involving hematopoietic stem and myeloid cells have been reported in patients with the newly defined VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. Here, we report clinical hematologic manifestations and unique bone marrow (BM) features in 16 patients with VEXAS. All patients were male and had a history of severe autoinflammatory and rheumatologic manifestations and a somatic UBA1 mutation (p.Met41). Ten patients had hematologic disorders: myelodysplastic syndrome (MDS; 6 of 16), multiple myeloma (2 of 16), monoclonal gammopathy of undetermined significance (2 of 16), and monoclonal B-cell lymphocytosis (2 of 16), and a few of those patients had 2 co-existing clonal processes. Although macrocytic anemia (100%) and lymphopenia (80%) were prevalent in all patients with VEXAS, thrombocytopenia and neutropenia were more common in patients with progression to MDS. All BMs in VEXAS patients had prominent cytoplasmic vacuoles in myeloid and erythroid precursors. In addition, most BMs were hypercellular with myeloid hyperplasia, erythroid hypoplasia, and varying degrees of dysplasia. All patients diagnosed with MDS were lower risk (low blast count, very good to intermediate cytogenetics) according to standard prognostic scoring with no known progression to leukemia. In addition, 10 of 16 patients had thrombotic events, including venous thromboembolism and arterial stroke. Although VEXAS presents symptomatically as a rheumatologic disease, morbidity and mortality are associated with progression to hematologic disease. Given the increased risk of developing MDS and multiple myeloma, surveillance for disease progression is important.

Development of a Hybrid Bioinorganic Nanobiocatalyst: Remarkable Impact of the Immobilization Conditions on Activity and Stability of ß-Galactosidase.

Hybrid bioinorganic biocatalysts have received much attention due to their simple synthesis, high efficiency, and structural features that favor enzyme activity and stability. The present work introduces a biomineralization strategy for the formation of hybrid nanocrystals from ß-galactosidase. The effects of the immobilization conditions were studied, identifying the important effect of metal ions and pH on the immobilization yield and the recovered activity. For a deeper understanding of the biomineralization process, an in silico study was carried out to identify the ion binding sites at the different conditions. The selected ß-galactosidase nanocrystals showed high specific activity (35,000 IU/g biocatalyst) and remarkable thermal stability with a half-life 11 times higher than the soluble enzyme. The nanobiocatalyst was successfully tested for the synthesis of galacto-oligosaccharides, achieving an outstanding performance, showing no signs of diffusional limitations. Thus, a new, simple, biocompatible and inexpensive nanobiocatalyst was produced with high enzyme recovery (82%), exhibiting high specific activity and high stability, with promising industrial applications.

Somatic Mutations in UBA1 Define a Distinct Subset of Relapsing Polychondritis Patients With VEXAS.

OBJECTIVE: Somatic mutations in UBA1 cause a newly defined syndrome known as VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome). More than 50% of patients currently identified as having VEXAS met diagnostic criteria for relapsing polychondritis (RP), but clinical features that characterize VEXAS within a cohort of patients with RP have not been defined. We undertook this study to define the prevalence of somatic mutations in UBA1 in patients with RP and to create an algorithm to identify patients with genetically confirmed VEXAS among those with RP. METHODS: Exome and targeted sequencing of UBA1 was performed in a prospective observational cohort of patients with RP. Clinical and immunologic characteristics of patients with RP were compared based on the presence or absence of UBA1 mutations. The random forest method was used to derive a clinical algorithm to identify patients with UBA1 mutations. RESULTS: Seven of 92 patients with RP (7.6%) had UBA1 mutations (referred to here as VEXAS-RP). Patients with VEXAS-RP were all male, were on average ≥45 years of age at disease onset, and commonly had fever, ear chondritis, skin involvement, deep vein thrombosis, and pulmonary infiltrates. No patient with VEXAS-RP had chondritis of the airways or costochondritis. Mortality was greater in VEXAS-RP than in RP (23% versus 4%; P = 0.029). Elevated acute-phase reactants and hematologic abnormalities (e.g., macrocytic anemia, thrombocytopenia, lymphopenia, multiple myeloma, myelodysplastic syndrome) were prevalent in VEXAS-RP. A decision tree algorithm based on male sex, a mean corpuscular volume >100 fl, and a platelet count <200 ×103 /µl differentiated VEXAS-RP from RP with 100% sensitivity and 96% specificity. CONCLUSION: Mutations in UBA1 were causal for disease in a subset of patients with RP. This subset of patients was defined by disease onset in the fifth decade of life or later, male sex, ear/nose chondritis, and hematologic abnormalities. Early identification is important in VEXAS given the associated high mortality rate.

ZnO Materials as Effective Anodes for the Photoelectrochemical Regeneration of Enzymatically Active NAD.

This work reports the study of ZnO-based anodes for the photoelectrochemical regeneration of the oxidized form of nicotinamide adenine dinucleotide (NAD+). The latter is the most important coenzyme for dehydrogenases. However, the high costs of NAD+ limit the use of such enzymes at the industrial level. The influence of the ZnO morphologies (flower-like, porous film, and nanowires), showing different surface area and crystallinity, was studied. The detection of diluted solutions (0.1 mM) of the reduced form of the coenzyme (NADH) was accomplished by the flower-like and the porous films, whereas concentrations greater than 20 mM were needed for the detection of NADH with nanowire-shaped ZnO-based electrodes. The photocatalytic activity of ZnO was reduced at increasing concentrations of NAD+ because part of the ultraviolet irradiation was absorbed by the coenzyme, reducing the photons available for the ZnO material. The higher electrochemical surface area of the flower-like film makes it suitable for the regeneration reaction. The illumination of the electrodes led to a significant increase on the NAD+ regeneration with respect to both the electrochemical oxidation in dark and the only photochemical reaction. The tests with formate dehydrogenase demonstrated that 94% of the regenerated NAD+ was enzymatically active.

Biocatalysis in the winemaking industry: Challenges and opportunities for immobilized enzymes.

Enzymes are powerful catalysts already being used in a large number of industrial processes. Impressive advantages in enzyme catalysts improvement have occurred in recent years aiming to improve their performance under harsh operation conditions far away from those of their cellular habitat. Production levels of the winemaking industry have experienced a remarkable increase, and technological innovations have been introduced for increasing the efficiency at different process steps or for improving wine quality, which is a key issue in this industry. Enzymes, such as pectinases and proteases, have been traditionally used, and others, such as glycosidases, have been more recently introduced in the modern wine industry, and many dedicated studies refer to the improvement of enzyme performance under winemaking conditions. Within this framework, a thorough review on the role of enzymes in winemaking is presented, with special emphasis on the use of immobilized enzymes as a significant strategy for catalyst improvement within an industry in which enzymes play important roles that are to be reinforced paralleling innovation.

Entrapment of enzyme aggregates in chitosan beads for aroma release in white wines.

Glycosidases are enzymes involved in the cascade reactions leading to the release of aromatic compounds in white wines. However, the use of commercial soluble glycosidases is facing difficulties due to their fast inactivation, poor reaction control, low efficiency of enzyme use, and the presence of catalyst residues in the product. Co-immobilization as cross-linked enzyme aggregates (combi-CLEAs) is a sound alternative allowing the immobilization of enzymes in their own protein matrix, yielding highly stable and active biocatalysts. Notwithstanding, their micrometer sized particles limit their application in industrial processes. To overcome this, combi-CLEAs of ß-D-glucosidase (ßG) and α-L-arabinofuranosidase (ARA) were entrapped in polymeric chitosan beads. The effect of crosslinking reagents and crosslinking time on the specific activity and stability of combi-CLEAs was studied, and the best conditions for the entrapment of the combi-CLEAs in polymeric chitosan beads were determined varying the concentration of the chitosan solution and the pH of the gelation agent solution. The resulting biocatalyst beads (average diameter 1.24 mm), retained full activity after 91 days of incubation under winemaking conditions, having specific activities of 0.91 and 0.88 international units of activity per gram for ßG and ARA, respectively. Such characteristics make them suitable for aroma enhancement in wines.

Parameters for the Evaluation of Immobilized Enzymes Under Process Conditions.

The characterization of immobilized enzymes allows the evaluation of the immobilization process itself and also the projection of the immobilized enzyme performance under process operation conditions. Based on such characterization, strategies for support functionalization and enzyme immobilization into the activated support can be selected, determining the best conditions for conducting such steps in view of the intended use of the biocatalyst, establishing a linkage between biocatalyst production and biocatalyst use. The determination of the catalytic potential of the immobilized enzyme under operational conditions is a priceless parameter that takes into account both activity and stability, including the effect of both mass transfer limitations (diffusional restrictions) and intrinsic enzyme inactivation upon the immobilization process.