RESUMEN
An efficient cyclization for the synthesis of 1,2,4,5-tetra-substituted benzenes via copper catalyzed dimerization of γ,δ-unsaturated ketones has been described. This one-pot procedure employs the γ,δ-unsaturated ketones as the sole substrate with multiple C-C bond formation. This protocol features broad substrate scope and provides a facile and robust method to construct polysubstituted benzene derivatives under mild conditions.
RESUMEN
BACKGROUND: The channel-forming protein Pannexin1 (Panx1) has been implicated in both human studies and animal models of chronic pain, but the underlying mechanisms remain incompletely understood. METHODS: Wild-type (WT, n = 24), global Panx1 KO (n = 24), neuron-specific Panx1 KO (n = 20), and glia-specific Panx1 KO (n = 20) mice were used in this study at Albert Einstein College of Medicine. The von Frey test was used to quantify pain sensitivity in these mice following complete Freund's adjuvant (CFA) injection (7, 14, and 21 d). The qRT-PCR was employed to measure mRNA levels of Panx1, Panx2, Panx3, Cx43, Calhm1, and ß-catenin. Laser scanning confocal microscopy imaging, Sholl analysis, and electrophysiology were utilized to evaluate the impact of Panx1 on neuronal excitability and morphology in Neuro2a and dorsal root ganglion neurons (DRGNs) in which Panx1 expression or function was manipulated. Ethidium bromide (EtBr) dye uptake assay and calcium imaging were employed to investigate the role of Panx1 in adenosine triphosphate (ATP) sensitivity. ß-galactosidase (ß-gal) staining was applied to determine the relative cellular expression levels of Panx1 in trigeminal ganglia (TG) and DRG of transgenic mice. RESULTS: Global or neuron-specific Panx1 deletion markedly decreased pain thresholds after CFA stimuli (7, 14, and 21 d; P < 0.01 vs. WT group), indicating that Panx1 was positively correlated with pain sensitivity. In Neuro2a, global Panx1 deletion dramatically reduced neurite extension and inward currents compared to the WT group (P < 0.05), revealing that Panx1 enhanced neurogenesis and excitability. Similarly, global Panx1 deletion significantly suppressed Wnt/ß-catenin dependent DRG neurogenesis following 5 d of nerve growth factor (NGF) treatment (P < 0.01 vs. WT group). Moreover, Panx1 channels enhanced DRG neuron response to ATP after CFA injection (P < 0.01 vs. Panx1 KO group). Furthermore, ATP release increased Ca2+ responses in DRGNs and satellite glial cells surrounding them following 7 d of CFA treatment (P < 0.01 vs. Panx1 KO group), suggesting that Panx1 in glia also impacts exaggerated neuronal excitability. Interestingly, neuron-specific Panx1 deletion was found to markedly reduce differentiation in cultured DRGNs, as evidenced by stunted neurite outgrowth (P < 0.05 vs. Panx1 KO group; P < 0.01 vs. WT group or GFAP-Cre group), blunted activation of Wnt/ß-catenin signaling (P < 0.01 vs. WT, Panx1 KO and GFAP-Cre groups), and diminished cell excitability (P < 0.01 vs. GFAP-Cre group) and response to ATP stimulation (P < 0.01 vs. WT group). Analysis of ß-gal staining showed that cellular expression levels of Panx1 in neurons are significantly higher (2.5-fold increase) in the DRG than in the TG. CONCLUSIONS: The present study revealed that neuronal Panx1 is a prominent driver of peripheral sensitivity in the setting of inflammatory pain through cell-autonomous effects on neuronal excitability. This hyperexcitability dependence on neuronal Panx1 contrasts with inflammatory orofacial pain, where similar studies revealed a prominent role for glial Panx1. The apparent differences in Panx1 expression in neuronal and non-neuronal TG and DRG cells are likely responsible for the distinct impact of these cell types in the two pain models.
Asunto(s)
Conexinas , Proteínas del Tejido Nervioso , Animales , Conexinas/genética , Ratones , Proteínas del Tejido Nervioso/genética , Modelos Animales de Enfermedad , Dolor/fisiopatología , Dolor/etiología , Neuronas/metabolismo , Inflamación/fisiopatología , Ratones Noqueados , MasculinoRESUMEN
Rhodium-catalyzed three-component C-H bond activation of aromatics with amides and aldehydes to synthesize amines was established. The addition of copper was found to be essential to ensure the high reactivity. The mechanistic studies indicated that key intermediates formed by the transmetallization between rhodium and copper could further promote the addition between 2-(pyridin-2-yl)-phenyl-metal species and imines. A series of densely substituted amines could be conveniently prepared by this one-step, three-component procedure from commercially available substrates via C-H bond activation with water as the only by-product.
RESUMEN
BACKGROUND: Cerebral venous sinus thrombosis (CVST) is typically associated with a prothrombotic state of the blood, with its causative factors varying widely. Prior research has not reported the simultaneous occurrence of CVST and dural arteriovenous fistulas (DAVFs) as potentially resulting from genetic mutations. In this case report, we introduce a unique occurrence wherein a patient with a heterozygous mutation of the low-density lipoprotein receptor (LDLR) gene presented with CVST in conjunction with DAVFs. CASE: Presentation: A male patient, aged 51, sought treatment at our facility due to a consistent decline in cognitive functions accompanied by recurrent headaches. Comprehensive evaluations were administered, including neurological examinations, laboratory tests, magnetic resonance imaging, digital subtraction angiography, and whole exome sequencing. Digital subtraction angiography identified DAVFs in the patient's right sigmoid sinus and an occlusion within the left transverse sinus. The whole exome sequencing of blood samples pinpointed a heterozygous mutation in the LDLR gene (NM_000527:exon12:c.C1747T:p.H583Y). Following the confirmed diagnosis of CVST and DAVFs, the patient underwent anticoagulant therapy combined with endovascular procedures - these comprised embolization of the arteriovenous fistula in the right sigmoid sinus and balloon dilation with stent implantation in the left transverse sinus. A six-month follow-up indicated a significant abatement in the patient's symptoms. CONCLUSIONS: This report marks the first documented case of an LDLR gene mutation that could be associated with the onset of CVST and DAVFs. The mutation in the LDLR gene might foster a prothrombotic environment, facilitating the gradual emergence of CVST and the subsequent genesis of DAVFs.
Asunto(s)
Malformaciones Vasculares del Sistema Nervioso Central , Embolización Terapéutica , Trombosis de los Senos Intracraneales , Humanos , Masculino , Malformaciones Vasculares del Sistema Nervioso Central/complicaciones , Malformaciones Vasculares del Sistema Nervioso Central/diagnóstico por imagen , Malformaciones Vasculares del Sistema Nervioso Central/genética , Angiografía Cerebral , Senos Craneales , Embolización Terapéutica/métodos , Trombosis de los Senos Intracraneales/complicaciones , Trombosis de los Senos Intracraneales/diagnóstico por imagen , Trombosis de los Senos Intracraneales/genética , Persona de Mediana EdadRESUMEN
Bicyclic boronates play critical roles in the discovery of functional materials and antibacterial agents, especially against deadly bacterial pathogens. Their practical and convenient preparation is in high demand but with great challenge. Herein, we report an efficient strategy for the preparation of bicyclic boronates through metal-free heteroatom-directed alkenyl sp2-CâH borylation. This synthetic approach exhibits good functional group compatibility, and the corresponding boronates bearing halides, aryls, acyclic and cyclic frameworks are obtained with high yields (43 examples, up to 95% yield). Furthermore, a gram-scale experiment is conducted, and downstream transformations of the bicyclic boronates are pursued to afford natural products, drug scaffolds, and chiral hemiboronic acid catalysts.
RESUMEN
The coronavirus disease (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged as a major public health crisis, posing a significant threat to human well-being. Despite the availability of vaccines, COVID-19 continues to spread owing to the emergence of SARS-CoV-2 mutants. This highlights the urgent need for the discovery of more effective drugs to combat COVID-19. As an important target for COVID-19 treatment, 3C-like protease (3CLpro) plays a crucial role in the replication of SARS-CoV-2. In our previous research, we demonstrated the potent inhibitory activities of compound A1, which contains a 2-sulfonyl-1,3,4-oxadiazole scaffold, against SARS-CoV-2 3CLpro. Herein, we present a detailed investigation of structural optimization of A1 and conduct a study on the structure-activity relationship. Among the various compounds tested, sulfoxide D6 demonstrates a potent irreversible inhibitory activity (IC50 = 0.030 µM) against SARS-CoV-2 3CLpro, as well as a favorable selectivity towards host cysteine proteases such as cathepsin B and cathepsin L. Utilizing mass spectrometry-based peptide profiling, we found that D6 covalently binds to Cys145 of SARS-CoV-2 3CLpro. Some representative compounds, namely C11, D9 and D10 also demonstrates antiviral activity against SARS-CoV-2 in Vero E6 cells. Overall, the investigation of the 2-sulfoxyl-1,3,4-oxadiazole scaffold as a novel cysteine reactive warhead would provide valuable insights into the design of potent covalent 3CLpro inhibitors for COVID-19 treatment.
Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Tratamiento Farmacológico de COVID-19 , Proteasas 3C de CoronavirusRESUMEN
In nature, cyclopropylcarbinyl cation is often involved in cationic cascade reactions catalyzed by natural enzymes to produce a great number of structurally diverse natural substances. However, mimicking this natural process with artificial organic catalysts remains a daunting challenge in synthetic chemistry. We report a small molecule-catalyzed asymmetric rearrangement of cyclopropylcarbinyl cations, leading to a series of chiral homoallylic sulfide products with good to excellent yields and enantioselectivities (up to 99% enantiomeric excess). In the presence of a chiral SPINOL-derived N-triflyl phosphoramide catalyst, the dehydration of prochiral cyclopropylcarbinols occurs rapidly to generate symmetrical cyclopropylcarbinyl cations, which are subsequently trapped by thione-containing nucleophiles. A subgram-scale experiment and multiple downstream transformations of the sulfide products are further pursued to demonstrate the synthetic utility. Notably, a few heteroaromatic sulfone derivatives could serve as "covalent warhead" in the enzymatic inhibition of severe acute respiratory syndrome coronavirus 2 main protease.
RESUMEN
OBJECTIVE: To analyze the characteristics and prognosis of acute leukemia(AL) with SET-NUP214 fusion gene. METHODS: The clinical data of 17 patients over 14 years old newly diagnosed with SET-NUP214 positive AL admitted in Institute of Hematology and Blood Diseases Hospital from August 2017 to May 2021 were analyzed retrospectively. RESULTS: Among the 17 SET-NUP214 positive patients, 13 cases were diagnosed as T-ALL (ETP 3 cases, Pro-T-ALL 6 cases, Pre-T-ALL 3 cases, Medullary-T-ALL 1 case), AML 3 cases (2 cases M5, 1 case M0) and ALAL 1 case. Thirteen patients presented extramedullary infiltration at initial diagnosis. All 17 patients received treatment, and a total of 16 cases achieved complete remission (CR), including 12 cases in patients with T-ALL. The total median OS and RFS time were 23 (3-50) months and 21 (0-48) months, respectively. Eleven patients received allogeneic hematopoietic stem cell transplantation(allo-HSCT), with median OS time of 37.5 (5-50) months and median RFS time of 29.5 (5-48) months. The median OS time of 6 patients in chemotherapy-only group was 10.5 (3-41) months, and median RFS time of 6.5 (3-39) months. The OS and RFS of patients with transplantation group were better than those of chemotherapy-only group (P=0.038). Among the 4 patients who relapsed or refractory after allo-HSCT, the SET-NUP214 fusion gene did not turn negative before transplantation. While, in the group of 7 patients who have not relapsed after allo-HSCT till now, the SET-NUP214 fusion gene expression of 5 patients turned negative before transplantation and other 2 of them were still positive. CONCLUSION: The fusion site of SET-NUP214 fusion gene is relatively fixed in AL patients, often accompanied by extramedullary infiltration. The chemotherapy effect of this disease is poor, and allo-HSCT may improve its prognosis.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Leucemia-Linfoma de Células T del Adulto , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Adolescente , Estudios Retrospectivos , Leucemia Mieloide Aguda/terapia , Enfermedad Aguda , Pronóstico , Leucemia-Linfoma de Células T del Adulto/terapia , Proteínas de Complejo Poro NuclearRESUMEN
A non-noble Cu-catalyzed transfer aza-benzyl Michael addition via the C-C bond cleavage of aza-benzyl alcohols has been disclosed. The unstrained C(sp3)-C(sp3) bond of an alcohol was selectively cleaved. This aza-benzyl transfer strategy provides a selective and environmentally benign approach for the C-alkylation of α,ß-unsaturated carbonyl compounds that employs readily available alcohols as carbon nucleophiles and is characterized by a wide range of substrates and good to excellent yields.
RESUMEN
Being the rate-limiting enzyme within the serine biosynthesis pathway, phosphoglycerate dehydrogenase (PHGDH) is abnormally overexpressed in numerous malignant tumor cells and is a promising target for cancer treatment. Here, we report a series of novel PHGDH inhibitors using a focused compound screening and structural optimization approach. The lead compound D8 displayed good enzymatic inhibitory activity (IC50 = 2.8 ± 0.1 µM), high binding affinity (Kd = 2.33 µM), and sensitivity to the cell lines with the PHGDH gene amplification or overexpression. Furthermore, D8 was proven to restrict the de novo serine synthesis from glucose within MDA-MB-468 cells. X-ray crystallographic analysis, molecular dynamics simulations, and mutagenesis experiments on PHGDH revealed the binding site at D175 inside the NAD+-binding pocket. Finally, D8 exhibited excellent in vivo pharmacokinetic properties (F = 82.0%) and exerted evident antitumor efficacy in the PC9 xenograft mouse model.
Asunto(s)
Neoplasias , Fosfoglicerato-Deshidrogenasa , Humanos , Animales , Ratones , Línea Celular Tumoral , Serina , Simulación de Dinámica Molecular , Sitios de Unión , Neoplasias/tratamiento farmacológicoRESUMEN
Recent studies have indicated that suppressing oxidative stress and ferroptosis can considerably improve the prognosis of intracerebral hemorrhage (ICH). Withaferin A (WFA), a natural compound, exhibits a positive effect on a number of neurological diseases. However, the effects of WFA on oxidative stress and ferroptosis-mediated signaling pathways to ICH remain unknown. In this study, we investigated the neuroprotective effects and underlying mechanism for WFA in the regulation of ICH-induced oxidative stress and ferroptosis. We established a mouse model of ICH by injection of autologous tail artery blood into the caudate nucleus and an in vitro cell model of hemin-induced ICH. WFA was injected intracerebroventricularly at 0.1, 1 or 5 µg/kg once daily for 7 days, starting immediately after ICH operation. WFA markedly reduced brain tissue injury and iron deposition and improved neurological function in a dose-dependent manner 7 days after cerebral hemorrhage. Through in vitro experiments, cell viability test showed that WFA protected SH-SY5Y neuronal cells against hemin-induced cell injury. Enzyme-linked immunosorbent assays in vitro and in vivo showed that WFA markedly decreased the level of malondialdehyde, an oxidative stress marker, and increased the activities of anti-oxidative stress markers superoxide dismutase and glutathione peroxidase after ICH. Western blot assay, quantitative polymerase chain reaction and immunofluorescence results demonstrated that WFA activated the nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling axis, promoted translocation of Nrf2 from the cytoplasm to nucleus, and increased HO-1 expression. Silencing Nrf2 with siRNA completely reversed HO-1 expression, oxidative stress and protective effects of WFA. Furthermore, WFA reduced hemin-induced ferroptosis. However, after treatment with an HO-1 inhibitor, the neuroprotective effects of WFA against hemin-induced ferroptosis were weakened. MTT test results showed that WFA combined with ferrostatin-1 reduced hemin-induced SH-SY5Y neuronal cell injury. Our findings reveal that WFA treatment alleviated ICH injury-induced ferroptosis and oxidative stress through activating the Nrf2/HO-1 pathway, which may highlight a potential role of WFA for the treatment of ICH.
RESUMEN
A regio- and chemoselective sulfonylation of propargyl alcohols with sulfinamides in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) was developed. It provided straightforward and mild access to multi-substituted allenyl sulfones by using sulfinamides as the sulfonyl sources. This transformation was promoted by HFIP and did not require any catalysts or oxidants, which allowed for the successful conversion of various tertiary and secondary propargyl alcohols into allenyl sulfones in high yields.
RESUMEN
The isomerization of allylic alcohols to the corresponding carbonyl compounds is a well-established reaction in organic synthesis. However, 1,3-carbon migration is a quite challenging field, and thus transformation has remained elusive until now. Herein, we present the ruthenium-catalyzed intramolecular 1,3-aryl migrative isomerization, which provides a mild and environmentally friendly method to synthesize various ketones with high step- and atom-economy and broad substrate scope. Meanwhile, the Ru(III)-catalyzed C(sp3)-C(aryl) bond cleavage of unactivated allylic alcohols may serve as a heuristic paradigm for transition-metal-catalyzed C-C activation.
RESUMEN
Carbon migration of alkenyl alcohols has been recognized as an increasingly viable methodology in organic synthesis. Herein, we disclose a silver-catalyzed 1,3-aza-benzyl migration of allyl alcohols by utilizing chelation-assisted selective cleavage of an unstrained C(sp3)-C(sp3) bond. This approach provides an available, efficient, high atom-economic, and environmentally benign procedure, leading to alkylation products with broad substrate scopes and excellent yields. The migration proceeds via a one-pot, two-step process involving a free-state alkyl metal species.
RESUMEN
The silver-catalyzed alkynyl borrowing amination of secondary propargyl alcohols via C(sp3)-C(sp) bond cleavage has been developed. This new strategy was based on the ß-alkynyl elimination of propargyl alcohols and alkynyl as the borrowing subject. This alkynyl borrowing amination featured high atom economy, wide functional group tolerance, and high efficiency.
Asunto(s)
Alcoholes , Plata , Alcoholes/química , Aminación , Catálisis , Plata/químicaRESUMEN
A highly regioselective and catalyst-free sulfonation of allylic alcohols with sulfinyl amides has been realized. Such a mix-and-go procedure provides a convenient approach to synthetically various allylic sulfones under mild reaction conditions. Furthermore, this novel reaction shows ample substrate scope and outstanding functional group tolerance and could also be scaled-up. Meanwhile, it is the first example that sulfinyl amides act as a powerful sulfur nucleophile in the reactions. 1,1,1,3,3,3-Hexafluoro-2-propanol (HFIP) as a solvent plays a critical role in allylic sulfonation.
RESUMEN
BACKGROUND: This study aimed to investigate the clinical outcome and related risk factors of fetal lateral ventriculomegaly (VM). METHODS: A retrospective analysis was performed on 255 cases diagnosed as fetal VM. Prenatal imaging examination was carried out. The pregnancy outcomes were investigated through follow-up. According to the prognosis of children, they were divided into case group and control group. Multivariate logistic regression was used to analyze the factors influencing the prognosis of hydrocephalus. RESULTS: After excluding the cases with either loss of follow-up or incomplete information, 102 cases were followed up. Twelve cases with poor prognosis were set as the case group. According to the maternal age, gestational age, gender of children, and follow-up time, 3 cases were selected from the other 90 cases for each child in the case group, respectively, and selected as the control group. Paired comparative analysis was performed on 48 cases. Using prognosis as a dependent variable, multivariate logistic regression analysis of the statistically significant factors indicated that the change speed of width ratio (CSWR) and maximum lateral ventricular width (MW) were associated with fetal prognosis. CONCLUSIONS: Our results suggested that CSWR and MW may have the value of predicting fetal prognosis.
Asunto(s)
Hidrocefalia , Ultrasonografía Prenatal , Niño , Femenino , Humanos , Hidrocefalia/diagnóstico por imagen , Hidrocefalia/epidemiología , Imagen por Resonancia Magnética , Embarazo , Pronóstico , Estudios Retrospectivos , Factores de RiesgoRESUMEN
Tripartite motif-containing 44 (TRIM44) was reported to be involved in the tumorigenesis of several tumors, but its function in laryngeal squamous cell carcinoma has not been investigated yet. In the present study, we aimed to elucidate the function of TRIM44 in laryngeal squamous cell carcinoma, and identify the compounds which could inhibit TRIM44 expression. Our results showed that TRIM44 was upregulated in tumor tissues and cell lines of laryngeal squamous cell carcinoma. Knockdown of TRIM44 significantly inhibited cell growth of laryngeal squamous cell carcinoma by suppressing TLR4, phosphorylated AKT and phosphorylated NF-κB p65 expression in vitro. Moreover, TRIM44 knockdown inhibited tumor growth in nude mice, which further suggested that TRIM44 exerted oncogenic activity in laryngeal squamous cell carcinoma. Interestingly, it was found that nuciferine significantly inhibited the mRNA levels of TRIM44 after screening a small natural compound library. Our further studies showed nuciferine markedly downregulated the protein levels of TRIM44 and its substrate TLR4 in a concentration-dependent manner in laryngeal squamous cell carcinoma cells. Moreover, the activation of downstream kinases of TLR4 such as AKT signaling pathway was also inhibited by nuciferine. Additionally, nuciferine markedly inhibited cell survival of laryngeal squamous cell carcinoma in a concentration-dependent manner. In contrast, TRIM44 overexpression significantly reduced the cytotoxicity of nuciferine in laryngeal squamous cell carcinoma cells. In conclusion, this study indicated that inhibiting TRIM44 would be a useful strategy for the treatment of laryngeal squamous cell carcinoma, and nuciferine could be a potential chemical applicated in the therapy of laryngeal squamous cell carcinoma.
Asunto(s)
Aporfinas , Neoplasias de Cabeza y Cuello , Péptidos y Proteínas de Señalización Intracelular , Animales , Carcinogénesis , Proteínas Portadoras , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Ratones , Ratones Desnudos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Receptor Toll-Like 4 , Proteínas de Motivos Tripartitos/metabolismoRESUMEN
Inhibition of tumor angiogenesis is a highly effective strategy for cancer treatment. Human antigen R (HuR), an RNA-binding protein, is overexpressed in many cancers and regulates the mRNAs of multiple angiogenic factors by binding to the adenylate-uridylate-rich element in their 3' untranslated region. HuR protein has been demonstrated to be an important regulatory factor in macrophage-mediated angiogenesis, a process in which macrophages are critical for tumor progression. Muscone is a synthetic equivalent of musk, and recent studies have shown that it has a regulatory effect on angiogenesis. In this study, we synthesized five series of muscone derivatives and discovered that compound ZM-32 was effective in preventing HuR RRM1/2-Vegf-a mRNA complex formation. ZM-32 bound to HuR RRM1/2 protein with a KD value of 521.7 nmol/L. Furthermore, ZM-32 inhibited endothelial cell proliferation, migration, and tubule formation, and suppressed the VEGF/VEGFR2/ERK1/2 signaling axis mediated by macrophages in vitro. We also demonstrated that ZM-32 effectively prevented the proliferation and migration of breast cancer cells and inhibited the growth and angiogenesis of MDA-MB-231 xenograft tumors without any obvious toxicity in vivo. Mechanistically, exposure to ZM-32 influenced the mRNA stability of Vegf-a and Mmp9 in a HuR-dependent manner in both macrophages and MDA-MB-231 cells. Thus, in this study we identified a new muscone derivative, ZM-32, with anti-angiogenesis effects mediated via targeting HuR in breast cancer, that may become a potentially valuable lead compound for anti-cancer angiogenesis.
Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Cicloparafinas/farmacología , Proteína 1 Similar a ELAV/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Neovascularización Patológica , Factor A de Crecimiento Endotelial Vascular/metabolismo , Animales , Neoplasias de la Mama/enzimología , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Proteína 1 Similar a ELAV/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Metaloproteinasa 9 de la Matriz/genética , Ratones , Ratones Desnudos , Células RAW 264.7 , Estabilidad del ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal , Factor A de Crecimiento Endotelial Vascular/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The traditional strategy to improve the efficiency of an entire coupled enzyme system relies on separate direction of the evolution of enzymes involved in their respective enzymatic reactions. This strategy can lead to enhanced single-enzyme catalytic efficiency but may also lead to loss of coordination among enzymes. This study aimed to overcome such shortcomings by executing a directed evolution strategy on multiple enzymes in one combined group that catalyzes the asymmetric biosynthesis of l-phosphinothricin. The genes of a glutamate dehydrogenase from Pseudomonas moorei (PmGluDH) and a glucose dehydrogenase from Exiguobacterium sibiricum (EsGDH), along with other gene parts (promoters, ribosomal binding sites (RBSs), and terminators) were simultaneously evolved. The catalytic efficiency of PmGluDH was boosted by introducing the beneficial mutation A164G (from 1.29 s-1mM-1 to 183.52 s-1mM-1), and the EsGDH expression level was improved by optimizing the linker length between the RBS and the start codon of gdh. The total turnover numbers of the bioreaction increased from 115 (GluDH WTNADPH) to 5846 (A164GNADPH coupled with low expression of EsGDH), and to 33950 (A164GNADPH coupled with high expression of EsGDH). The coupling efficiency was increased from â¼30% (GluDH_WT with low expression of GDH) to 83.3% (GluDH_A164G with high expression of GDH). In the batch production of l-phosphinothricin utilizing whole-cell catalysis, the strongest biocatalytic reaction exhibited a high space-time yield (6410 g·L-1·d-1) with strict stereoselectivity (>99% enantiomeric excess).Importance: The traditional strategy to improve multienzyme-catalyzed reaction efficiency may lead to enhanced single-enzyme catalytic efficiency but may also result in loss of coordination among enzymes. We describe a directed evolution strategy of an entire coupled enzyme system to simultaneously enhance enzyme coordination and catalytic efficiency. The simultaneous evolution strategy was applied to a multienzyme-catalyzed reaction for the asymmetric synthesis of l-phosphinothricin, which not only enhanced the catalytic efficiency of GluDH but also improved the coordination between GluDH and GDH. Since this strategy is enzyme-independent, it may be applicable to other coupled enzyme systems for chiral chemical synthesis.