RESUMEN
Hydrothermal vents are geographically widespread and host microorganisms with robust enzymes useful in various industrial applications. We examined microbial communities and carboxylesterases of two terrestrial hydrothermal vents of the volcanic island of Ischia (Italy) predominantly composed of Firmicutes, Proteobacteria, and Bacteroidota. High-temperature enrichment cultures with the polyester plastics polyhydroxybutyrate and polylactic acid (PLA) resulted in an increase of Thermus and Geobacillus species and to some extent Fontimonas and Schleiferia species. The screening at 37 to 70°C of metagenomic fosmid libraries from above enrichment cultures identified three hydrolases (IS10, IS11, and IS12), all derived from yet-uncultured Chloroflexota and showing low sequence identity (33 to 56%) to characterized enzymes. Enzymes expressed in Escherichia coli exhibited maximal esterase activity at 70 to 90°C, with IS11 showing the highest thermostability (90% activity after 20-min incubation at 80°C). IS10 and IS12 were highly substrate promiscuous and hydrolyzed all 51 monoester substrates tested. Enzymes were active with PLA, polyethylene terephthalate model substrate, and mycotoxin T-2 (IS12). IS10 and IS12 had a classical α/ß-hydrolase core domain with a serine hydrolase catalytic triad (Ser155, His280, and Asp250) in their hydrophobic active sites. The crystal structure of IS11 resolved at 2.92 Å revealed the presence of a N-terminal ß-lactamase-like domain and C-terminal lipocalin domain. The catalytic cleft of IS11 included catalytic Ser68, Lys71, Tyr160, and Asn162, whereas the lipocalin domain enclosed the catalytic cleft like a lid and contributed to substrate binding. Our study identified novel thermotolerant carboxylesterases with a broad substrate range, including polyesters and mycotoxins, for potential applications in biotechnology. IMPORTANCE High-temperature-active microbial enzymes are important biocatalysts for many industrial applications, including recycling of synthetic and biobased polyesters increasingly used in textiles, fibers, coatings and adhesives. Here, we identified three novel thermotolerant carboxylesterases (IS10, IS11, and IS12) from high-temperature enrichment cultures from Ischia hydrothermal vents and incubated with biobased polymers. The identified metagenomic enzymes originated from uncultured Chloroflexota and showed low sequence similarity to known carboxylesterases. Active sites of IS10 and IS12 had the largest effective volumes among the characterized prokaryotic carboxylesterases and exhibited high substrate promiscuity, including hydrolysis of polyesters and mycotoxin T-2 (IS12). Though less promiscuous than IS10 and IS12, IS11 had a higher thermostability with a high temperature optimum (80 to 90°C) for activity and hydrolyzed polyesters, and its crystal structure revealed an unusual lipocalin domain likely involved in substrate binding. The polyesterase activity of these enzymes makes them attractive candidates for further optimization and potential application in plastics recycling.
Asunto(s)
Hidrolasas de Éster Carboxílico , Respiraderos Hidrotermales , Hidrolasas de Éster Carboxílico/metabolismo , Polímeros , Hidrolasas/metabolismo , Poliésteres , Plásticos , Especificidad por SustratoRESUMEN
Proteases are abundant in prokaryotic genomes (~10 per genome), but their recovery encounters expression problems, as only 1% can be produced at high levels; this value differs from that of similarly abundant esterases (1-15 per genome), 50% of which can be expressed at good levels. Here, we design a catalytically efficient artificial protease that can be easily produced. The PluriZyme EH1AB1 with two active sites supporting the esterase activity was employed. A Leu24Cys mutation in EH1AB1, remodelled one of the esterase sites into a proteolytic one through the incorporation of a catalytic dyad (Cys24 and His214). The resulting artificial enzyme, EH1AB1C, efficiently hydrolysed (azo)casein at pH 6.5-8.0 and 60-70 °C. The presence of both esterase and protease activities in the same scaffold allowed the one-pot cascade synthesis (55.0 ± 0.6% conversion, 24 h) of L-histidine methyl ester from the dipeptide L-carnosine in the presence of methanol. This study demonstrates that active sites supporting proteolytic activity can be artificially introduced into an esterase scaffold to design easy-to-produce in-one protease-esterase PluriZymes for cascade reactions, namely, the synthesis of amino acid esters from dipeptides. It is also possible to design artificial proteases with good production yields, in contrast to natural proteases that are difficult to express.
Asunto(s)
Esterasas , Péptido Hidrolasas , Esterasas/metabolismo , Péptido Hidrolasas/metabolismo , Endopeptidasas/metabolismo , Dominio Catalítico/genética , Ésteres/metabolismo , Concentración de Iones de HidrógenoRESUMEN
Engineering dual-function single polypeptide catalysts with two abiotic or biotic catalytic entities (or combinations of both) supporting cascade reactions is becoming an important area of enzyme engineering and catalysis. Herein we present the development of a PluriZyme, TR2 E2 , with efficient native transaminase (kcat : 69.49±1.77â min-1 ) and artificial esterase (kcat : 3908-0.41â min-1 ) activities integrated into a single scaffold, and evaluate its utility in a cascade reaction. TR2 E2 (pHopt : 8.0-9.5; Topt : 60-65 °C) efficiently converts methyl 3-oxo-4-(2,4,5-trifluorophenyl)butanoate into 3-(R)-amino-4-(2,4,5-trifluorophenyl)butanoic acid, a crucial intermediate for the synthesis of antidiabetic drugs. The reaction proceeds through the conversion of the ß-keto ester into the ß-keto acid at the hydrolytic site and subsequently into the ß-amino acid (e.e. >99 %) at the transaminase site. The catalytic power of the TR2 E2 PluriZyme was proven with a set of ß-keto esters, demonstrating the potential of such designs to address bioinspired cascade reactions.
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Aminoácidos , Transaminasas , Catálisis , Esterasas , Ésteres/química , HidrólisisRESUMEN
The regioselective α-glucosylation of hesperetin was achieved by a transglycosylation reaction catalyzed by cyclodextrin glucanotransferase (CGTase) from Thermoanaerobacter sp. using soluble starch as glucosyl donor. By combining mass spectrometry (ESI-TOF) and 2D-NMR analysis, the main monoglucosylated derivative was fully characterized (hesperetin 7-O-α-d-glucopyranoside). In order to increase the yield of monoglucoside, several reaction parameters were optimized: Nature and percentage of cosolvent, composition of the aqueous phase, glucosyl donor, temperature, and the concentrations of hesperetin and soluble starch. Under the optimal conditions, which included the presence of 30% of bis(2-methoxyethyl) ether as cosolvent, the maximum concentration of monoglucoside was approximately 2 mM, obtained after 24 h of reaction. To our knowledge, this is the first report of direct glucosylation of hesperetin employing free enzymes instead of whole cells.
Asunto(s)
Glucosiltransferasas/química , Hesperidina/química , Catálisis , Cromatografía Líquida de Alta Presión , Glucosiltransferasas/metabolismo , Glicosilación , Hesperidina/metabolismo , Espectrometría de Masas , Estructura MolecularRESUMEN
The synthesis of a novel α-glucosylated derivative of pterostilbene was performed by a transglycosylation reaction using starch as glucosyl donor, catalyzed by cyclodextrin glucanotransferase (CGTase) from Thermoanaerobacter sp. The reaction was carried out in a buffer containing 20% (v/v) DMSO to enhance the solubility of pterostilbene. Due to the formation of several polyglucosylated products with CGTase, the yield of monoglucoside was increased by the treatment with a recombinant amyloglucosidase (STA1) from Saccharomyces cerevisiae (var. diastaticus). This enzyme was not able to hydrolyze the linkage between the glucose and pterostilbene. The monoglucoside was isolated and characterized by combining ESI-MS and 2D-NMR methods. Pterostilbene α-d-glucopyranoside is a novel compound. The α-glucosylation of pterostilbene enhanced its solubility in water to approximately 0.1 g/L. The α-glucosylation caused a slight loss of antioxidant activity towards ABTSË⺠radicals. Pterostilbene α-d-glucopyranoside was less toxic than pterostilbene for human SH-S5Y5 neurons, MRC5 fibroblasts and HT-29 colon cancer cells, and similar for RAW 264.7 macrophages.
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Antineoplásicos/síntesis química , Antioxidantes/síntesis química , Proteínas Bacterianas/química , Glucano 1,4-alfa-Glucosidasa/química , Glucósidos/síntesis química , Glucosiltransferasas/química , Estilbenos/química , Animales , Antineoplásicos/farmacología , Antioxidantes/farmacología , Proteínas Bacterianas/aislamiento & purificación , Biocatálisis , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Fibroblastos/patología , Glucano 1,4-alfa-Glucosidasa/biosíntesis , Glucósidos/farmacología , Glucosiltransferasas/biosíntesis , Glicosilación , Células HT29 , Humanos , Concentración 50 Inhibidora , Ratones , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Células RAW 264.7 , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/enzimología , Solubilidad , Almidón/química , Thermoanaerobacter/química , Thermoanaerobacter/enzimologíaRESUMEN
The acylation of flavonoids serves as a means to alter their physicochemical properties, enhance their stability, and improve their bioactivity. Compared with natural flavonoid glycosides, the acylation of nonglycosylated flavonoids presents greater challenges since they contain fewer reactive sites. In this work, we propose an efficient strategy to solve this problem based on a first α-glucosylation step catalyzed by a sucrose phosphorylase, followed by acylation using a lipase. The method was applied to phloretin, a bioactive dihydrochalcone mainly present in apples. Phloretin underwent initial glucosylation at the 4'-OH position, followed by subsequent (and quantitative) acylation with C8, C12, and C16 acyl chains employing an immobilized lipase from Thermomyces lanuginosus. Electrospray ionization-mass spectrometry (ESI-MS) and two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR) confirmed that the acylation took place at 6-OH of glucose. The water solubility of C8 acyl glucoside closely resembled that of aglycone, but for C12 and C16 derivatives, it was approximately 3 times lower. Compared with phloretin, the radical scavenging capacity of the new derivatives slightly decreased with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and was similar to 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTSâ¢+). Interestingly, C12 acyl-α-glucoside displayed an enhanced (3-fold) transdermal absorption (using pig skin biopsies) compared to phloretin and its α-glucoside.
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Flavonoides , Malus , Animales , Porcinos , Flavonoides/química , Floretina , Malus/química , Glucósidos , Acilación , Lipasa/química , AntioxidantesRESUMEN
Metal complexes introduced into protein scaffolds can generate versatile biomimetic catalysts endowed with a variety of catalytic properties. Here, we synthesized and covalently bound a bipyridinyl derivative to the active centre of an esterase to generate a biomimetic catalyst that shows catecholase activity and enantioselective catalytic oxidation of (+)-catechin.
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Complejos de Coordinación , Esterasas , Estereoisomerismo , Oxidación-Reducción , CatálisisRESUMEN
Family VIII esterases present similarities to class C ß-lactamases, which show nucleophilic serines located at the S-X-X-K motif instead of the G-X-S-X-G or G-D-S-(L) motif shown by other carboxylesterase families. Here, we report the crystal structure of a novel family VIII (subfamily VIII. I) esterase (EH7 ; denaturing temperature, 52.6 ± 0.3 °C; pH optimum 7.0-9.0) to deepen its broad substrate range. Indeed, the analysis of the substrate specificity revealed its capacity to hydrolyse nitrocefin as a model chromogenic cephalosporin substrate (40.4 ± 11.4 units·g-1 ), and a large battery of 66 structurally different esters (up to 1730 min-1 ), including bis(2-hydroxyethyl)-terephthalate (241.7 ± 8.5 units·g-1 ) and the mycotoxin T-2 (1220 ± 52 units·g-1 ). It also showed acyltransferase activity through the synthesis of benzyl 3-oxobutanoate (40.4 ± 11.4 units·g-1 ) from benzyl alcohol and vinyl acetoacetate. Such a broad substrate scope is rare among family VIII esterases and lipolytic enzymes. Structural analyses of free and substrate-bound forms of this homooctamer esterase suggest that EH7 presents a more opened and exposed S1 site having no steric hindrance for the entrance of substrates to the active site, more flexible R1, R2 and R3 regions allowing for the binding of a wide spectrum of substrates into the active site, and small residues in the conserved motif Y-X-X containing the catalytic Tyr enabling the entrance of large substrates. These unique structural elements in combination with docking experiments allowed us to gain valuable insights into the substrate specificity of this esterase and possible others belonging to family VIII.
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Esterasas , beta-Lactamasas , beta-Lactamasas/química , Especificidad por Sustrato , Esterasas/metabolismo , Carboxilesterasa/metabolismo , Dominio CatalíticoRESUMEN
(-)-Epigallocatechin gallate (EGCG), the predominant catechin (≥50%) in green tea (Camellia sinensis), displays several bioactive properties but its stability and bioavailability are low. In this work, the properties of two α-glucosyl derivatives of EGCG (3'- and 7-O-α-D-glucopyranoside), obtained by enzymatic synthesis, were assessed. The α-glucosylation enhanced the pH and thermal stability of EGCG. The analysis of scavenging activity toward ABTS·+ radicals showed that the α-glucosylation at C-7 of A-ring caused a higher loss of antioxidant activity compared with the sugar conjugation at C-3' of B-ring. The 3'-glucoside also showed higher potential to alleviate intracellular reactive oxygen species (ROS) levels and to boost REDOX activity. The toxicity of EGCG and its monoglucosides was tested in human SH-S5Y5 neurons, RAW 264.7 macrophages, MRC5 fibroblasts, and HT-29 colon cancer cells. Interestingly, the 3'-O-α-D-glucoside increased the viability of neural cells in vitro (2.75-fold at 100 µM) in the presence of H2O2, whilst EGCG gave rise only to a 1.7-fold enhancement. In conclusion, the α-glucoside of EGCG at C-3' has a great potential for nutraceutical, cosmetic and biomedical applications.
RESUMEN
The glycosylation of plant polyphenols may modulate their solubility and bioavailability and protect these molecules from oxygen, light degradation, and during gastrointestinal transit. In this work, the synthesis of various α-glucosyl derivatives of (-)-epigallocatechin gallate, the predominant catechin in green tea, was performed in water at 50 °C by a transglycosylation reaction catalyzed by cyclodextrin glycosyltransferase from Thermoanaerobacter sp. The molecular weight of reaction products was determined by high-performance liquid chromatography coupled to mass spectrometry. Using hydrolyzed potato starch as a glucosyl donor, two main monoglucosides were obtained with conversion yields of 58 and 13%, respectively. The products were isolated and chemically characterized by combining two-dimensional nuclear magnetic resonance methods. The major derivative was epigallocatechin gallate 3'- O-α-d-glucopyranoside (1), and the minor derivative was epigallocatechin gallate 7- O-α-d-glucopyranoside (2).
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Proteínas Bacterianas/química , Catequina/análogos & derivados , Glucosiltransferasas/química , Thermoanaerobacter/enzimología , Biocatálisis , Catequina/química , Cromatografía Líquida de Alta Presión , Glicosilación , Espectrometría de MasasRESUMEN
Carbohydrate fatty acid esters have a broad spectrum of applications in the food, cosmetic, and pharmaceutical industries. The enzyme-catalyzed acylation is significantly more selective than the chemical process and is carried out at milder conditions. Compared with mono- and disaccharides, the acylation of trisaccharides has been less studied. However, trisaccharide esters display notable bioactive properties, probably due to the higher hydrophilicity of the sugar head group. In this chapter, we describe the acylation of two trisaccharides, maltotriose and 1-kestose, catalyzed by different immobilized lipases, using vinyl esters as acyl donors. To illustrate the potential of such compounds, the antitumor activity of 6â³-O-palmitoyl-maltotriose is shown.
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Ésteres/metabolismo , Ácidos Grasos/metabolismo , Lipasa/metabolismo , Trisacáridos/metabolismo , Acilación , Catálisis , Línea Celular , Cromatografía Líquida de Alta Presión , Ésteres/química , Ácidos Grasos/química , Humanos , Espectrometría de Masas , Trisacáridos/químicaRESUMEN
RATIONALE, AIMS AND OBJECTIVES: Differences in the performance of medical care may be due to variation in the introduction and diffusion of medical innovations. The objective of this paper is to compare seven European countries (United Kingdom, the Netherlands, West Germany, France, Spain, Estonia and Sweden) with regard to the year of introduction of six specific pharmaceutical innovations (antiretroviral drugs, cimetidine, tamoxifen, cisplatin, oxalaplatin and cyclosporin) that may have had important population health impacts. METHODS: We collected information on introduction and further diffusion of drugs using searches in the national and international literature, and questionnaires to national informants. We combined various sources of information, both official years of registration and other indicators of introduction (clinical trials, guidelines, evaluation reports, sales statistics). RESULTS AND CONCLUSIONS: The total length of the period between first and last introduction varied between 8 years for antiretroviral drugs and 22 years for cisplatin. Introduction in Estonia was generally delayed until the 1990s. The average time lags were smallest in France (2.2 years), United Kingdom (2.8 years) and the Netherlands (3.5 years). Similar rank orders were seen for year of registration suggesting that introduction lags are not only explained by differences in the process of registration. We discuss possible reasons for these between-country differences and implications for the evaluation of medical care.
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Difusión de Innovaciones , Aprobación de Drogas , Preparaciones Farmacéuticas , Europa (Continente) , Humanos , Calidad de la Atención de Salud , Encuestas y Cuestionarios , Factores de TiempoRESUMEN
BACKGROUND: Factor V leiden and the -G20210A variant of prothrombin gene are associated to a higher risk of deep venous thrombosis. AIM: To assess the frequency of factor V Leiden (G1691A) and prothrombin -G20210A alleles in patients with deep venous thrombosis (DVT) and in the general population from Spain. MATERIAL AND METHODS: Factor V Leiden (g1691a) and prothrombin-g20210a alleles were genotyped in 493 individuals from the Spanish general populations and in 131 patients with DVT. The presence of DVT was confirmed by phlebography. Allelic frequencies and the DVT risk associated with these variants were estimated. RESULTS: Allelic frequencies for the factor V Leiden (G1691A) allele were 0.019 in patients with DVT and 0.010 in the general population (p=0.235). The frequencies for the prothrombin-G20210A allele were 0.027 and 0.026 (p=0.975). After adjustment for age and gender, the odds ratio for DVT, associated with the presence of G1691A allele was 2.41, but not statistically significant (95% confidence intervals 0.63-9.19). CONCLUSIONS: Prothrombin-G20210A allele was more prevelant than factor V Leiden (G1691A) allele in the Spanish population. However, the magnitude of the association between the G20210A and DVT risk is very low. On the contrary, the G1691A allele is associated by itself with a two fold increase in DVT risk in this population although without reaching statistical significance due to its low frequency.
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Factor V/genética , Frecuencia de los Genes/genética , Protrombina/genética , Trombosis de la Vena/genética , Femenino , Marcadores Genéticos , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Análisis Multivariante , Factores de Riesgo , EspañaRESUMEN
BACKGROUND: Leprosy is a chronic infectious disease that is considered to be declining, though it still remains prevalent in many parts of the world. A study was made to explore the health and socioeconomic factors that most influenced the trend of the disease in a typical Mediterranean country. MATERIALS AND METHODS: An ecological study was conducted, investigating possible social, economic and health factors related to the evolution of leprosy incidence. The time period considered was 50 years--the second half of the twentieth century in Spain. RESULTS: The variables showing the strongest correlation to evolution of the incidence of the disease were employment, the number of physicians, and the gross domestic product (GDP), with negative coefficients--while tuberculosis showed a positive coefficient. However, the GDP showed the highest coefficient (0.5). The model that best explained the evolution of leprosy over the last 50 years comprised a 6-year lag period between the socioeconomic factors and the incidence of leprosy--explaining 57% of the data obtained. The annual decrease in leprosy incidence was 1.6%. CONCLUSIONS: Socioeconomic development, assessed in terms of the GDP, was the most important factor in explaining the evolution of leprosy incidence.
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Lepra/epidemiología , Empleo , Humanos , Incidencia , Lepra/economía , Estudios Longitudinales , Médicos/provisión & distribución , Factores Socioeconómicos , España/epidemiologíaRESUMEN
Background: Factor V leiden and the -G20210A variant of prothrombin gene are associated to a higher risk of deep venous thrombosis. Aim: To assess the frequency of factor V Leiden (G1691A) and prothrombin -G20210A alleles in patients with deep venous thrombosis (DVT) and in the general population from Spain. Material and methods: Factor V Leiden (g1691a) and prothrombin-g20210a alleles were genotyped in 493 individuals from the Spanish general populations and in 131 patients with DVT. The presence of DVT was confirmed by phlebography. Allelic frequencies and the DVT risk associated with these variants were estimated. Results: Allelic frequencies for the factor V Leiden (G1691A) allele were 0.019 in patients with DVT and 0.010 in the general population (p=0.235). The frequencies for the prothrombin-G20210A allele were 0.027 and 0.026 (p=0.975). After adjustment for age and gender, the odds ratio for DVT, associated with the presence of G1691A allele was 2.41, but not statistically significant (95% confidence intervals 0.63-9.19). Conclusions: Prothrombin-G20210A allele was more prevelant than factor V Leiden (G1691A) allele in the Spanish population. However, the magnitude of the association between the G20210A and DVT risk is very low. On the contrary, the G1691A allele is associated by itself with a two fold increase in DVT risk in this population although without reaching statistical significance due to its low frequency.