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1.
Nat Commun ; 15(1): 181, 2024 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-38185711

RESUMEN

Metazoans use silicon traces but rarely develop extensive silica skeletons, except for the early-diverging lineage of sponges. The mechanisms underlying metazoan silicification remain incompletely understood, despite significant biotechnological and evolutionary implications. Here, the characterization of two proteins identified from hexactinellid sponge silica, hexaxilin and perisilin, supports that the three classes of siliceous sponges (Hexactinellida, Demospongiae, and Homoscleromorpha) use independent protein machineries to build their skeletons, which become non-homologous structures. Hexaxilin forms the axial filament to intracellularly pattern the main symmetry of the skeletal parts, while perisilin appears to operate in their thickening, guiding extracellular deposition of peripheral silica, as does glassin, a previously characterized hexactinellid silicifying protein. Distant hexaxilin homologs occur in some bilaterians with siliceous parts, suggesting putative conserved silicifying activity along metazoan evolution. The findings also support that ancestral Porifera were non-skeletonized, acquiring silica skeletons only after diverging into major classes, what reconciles molecular-clock dating and the fossil record.


Asunto(s)
Poríferos , Dióxido de Silicio , Animales , Biomineralización , Silicio , Vendajes , Poríferos/genética
2.
Adv Clin Chem ; 112: 155-204, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36642483

RESUMEN

Immune checkpoint inhibitors (ICI) are key drugs in systemic therapy for advanced non-small-cell lung cancer (NSCLC) and have recently been incorporated into neoadjuvant and adjuvant settings for surgical resection. Currently, ICI combinations with cytotoxic agents are frequently used in clinical practice, although several ICI clinical trials have failed to produce long-term clinical benefits. Unfortunately, clinical benefit is moderate and limited considering physical and financial burden. Therefore, selecting appropriate patients and regimens for ICI therapy is important, and biomarkers are necessary for their selection. Tumor PD-L1 expression is universally used as a biomarker; however, PD-L1 assays show low analytical validity and reproducibility due to the visual-scoring system by pathologists. Recent tumor immunology studies explore that neoantigens derived from somatic mutations and the collaboration between T and B cells efficiently elicit antitumor responses. This suggests that high tumor mutational burden and T-cell infiltration are predictive biomarkers. However, B cells producing antibody (Ab) remain poorly understood and analyzed as biomarkers. We found that NY-ESO-1 and XAGE1 of cancer-testis antigen frequently elicit spontaneous humoral and cellular immune responses in NSCLC. Serum Ab against these antigens were detected in approximately 25% of NSCLC patients and predicted ICI monotherapy responses. In addition, the Ab levels were decreased with tumor shrinkage after ICI therapy. Thus, NY-ESO-1 and XAGE1 Ab are potentially biomarkers predicting and monitoring response to ICI therapy. For clinical applications, a fully-automated assay system measuring the Ab was developed. Here, we review current ICI therapy, tumor immunology, and biomarkers in NSCLC, and discuss the applicability of the serum biomarkers NY-ESO-1 and XAGE1 Ab.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Inhibidores de Puntos de Control Inmunológico , Neoplasias Pulmonares , Humanos , Masculino , Anticuerpos , Antígenos de Neoplasias , Antígeno B7-H1 , Biomarcadores , Biomarcadores de Tumor , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamiento farmacológico , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Reproducibilidad de los Resultados , Inhibidores de Puntos de Control Inmunológico/uso terapéutico
3.
J Sci Food Agric ; 103(7): 3685-3690, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36321533

RESUMEN

BACKGROUND: Vitamin B12 is an essential vitamin that is absent in plant-derived foods such as fruits and vegetables. This can result in an increased risk of developing vitamin B12 deficiency in strict vegetarians (vegans). There are several studies that have aimed to enhance nutrients in food crops. The purpose of the present study was to fortify tomato fruits with vitamin B12 (or cyanocobalamin). RESULTS: Tomato plants were grown for 70 days in hydroponic culture pots and treated with 5 µm of cyanocobalamin on days 1-24 after the fruiting, and then harvested for tomato fruits. The ripened tomato fruits contained 4.0 × 10-7  g of cyanocobalamin per 100 g of dry weight and showed a significant increase in glucose and lycopene levels. CONCLUSION: The present study highlights the use of a cyanocobalamin-supplementation system for the production of B12 fortified tomato fruits that can help prevent B12 deficiency in vegetarians. © 2022 Society of Chemical Industry.


Asunto(s)
Solanum lycopersicum , Hidroponía , Frutas/química , Vitamina B 12/análisis , Vitaminas/análisis
4.
J Biosci Bioeng ; 134(6): 477-483, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36192321

RESUMEN

Glassin is a water-soluble protein from the siliceous skeleton of a marine sponge that adsorbs tightly to silica at pH 7.0-9.0 and accelerates silica particle formation from silicic acid. Glassin comprises three distinct domains: a His and Asp-rich (HD) domain, a Pro-rich (P) domain, and a His and Thr-rich (HT) domain. Here, we investigated the roles of these three domains in silica adsorption by using glutathione S-transferase (GST) fused with glassin or with each domain. GST fused with the HD domain exhibited tight adsorption, equivalent to that of GST fused with the full-length glassin sequence at values above 7.0. The apparent Kd values for the binding of full-length glassin and HD to fumed silica at pH 7.0 were 20.8 and 22.7 nM, respectively, indicating that this domain greatly contributes to the silica adsorption ability of glassin. In addition, no internal cleavage was observed in the HD domain, whereas GST fused with the full-length glassin sequence exhibited internal cleavage. The HD domain adsorbed on silica did not dissociate even at pH 6.0. Given these findings, we concluded that the HD domain has potential as a tag for the immobilization of soluble proteins.


Asunto(s)
Dióxido de Silicio
5.
Anticancer Res ; 41(11): 5469-5475, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34732416

RESUMEN

BACKGROUND/AIM: We evaluated the efficacy of "the tumor immune microenvironment (TIME) classification" for predicting clinical response to immune checkpoint inhibitors (ICIs) in patients with non-small cell lung cancer (NSCLC). In addition, we aimed to evaluate the "modified TIME classification", which adds the vascular endothelial growth factor (VEGF) status to TIME. MATERIALS AND METHODS: Programmed cell death receptor ligand-1 (PD-L1), CD8 T cell tumor-infiltrating lymphocytes (CD8+TILs) count and VEGF expression analyses were performed using immuno - histochemistry in 44 patients who had undergone ICI monotherapy. RESULTS: Regarding TIME classification, type-I (PD-L1 high and CD8+TILs high) had a significantly higher response than the other types. Using the modified TIME classification, type-IA (PD-L1 high, CD8+TILs high, and VEGF low) had a significantly higher response than the other types. CONCLUSION: The modified TIME classification, which adds tumor VEGF expression to "the TIME classification", could be useful in predicting clinical response to ICI monotherapy.


Asunto(s)
Antígeno B7-H1/antagonistas & inhibidores , Linfocitos T CD8-positivos/inmunología , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Neoplasias Pulmonares/tratamiento farmacológico , Linfocitos Infiltrantes de Tumor/inmunología , Factor A de Crecimiento Endotelial Vascular/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Antígeno B7-H1/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Progresión de la Enfermedad , Femenino , Humanos , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Supervivencia sin Progresión , Microambiente Tumoral
6.
Thorac Cancer ; 12(6): 775-782, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33491334

RESUMEN

BACKGROUND: Immune checkpoint inhibitors targeting the programmed cell death-1 (PD-1)/PD-1 ligand 1 (PD-L1) axis have shown promising results in patients with nonsmall cell lung cancer (NSCLC). One major PD-L1 inducer is IFNγ, which is secreted by T cells and NK cells. Importantly, IFNγ-induced PD-L1 is one of the major mechanisms by which cancer cells escape host immunity. METHODS: Here, we found that the NSCLC cell line, LC-2/ad, has a unique character; the PD-L1 expression in these cells is up-regulated by both IFNγ and epidermal growth factor (EGF). RESULTS: Comparative analysis of the cell signaling pathway showed that IFNγ activates STAT1 signaling, while EGF activates AKT, MAPK, and ribosomal protein S6 kinase in LC-2/ad cells. IFNγ-induced PD-L1, but not EGF-induced PD-L1, was clearly blocked by the JAK-STAT inhibitor tofacitinib. Interestingly, IFNγ decreased the expression of NK cell-activating ligands while increasing the expression of MHC class I molecules, resulting in a phenotype that can easily escape from NK cells, theoretically. Finally, we showed that IFNγ stimuli attenuated NK cell-mediated cytotoxicity in LC-2/ad cells, which was, however, blocked by tofacitinib. CONCLUSIONS: Taken together, our study shows that tofacitinib blocks the IFNγ-induced transformation from an NK cell-sensitive phenotype to an NK cell-resistant one in IFNγ-reacted LC-2/ad cells, thereby implicating that tofacitinib may be a promising agent to overcome IFNγ-induced tumor immune escape, although it may be adapted to the limited number of NSCLC patients.


Asunto(s)
Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Interferón gamma/efectos adversos , Células Asesinas Naturales/inmunología , Fragmentos de Péptidos/efectos adversos , Piperidinas/uso terapéutico , Inhibidores de Proteínas Quinasas/uso terapéutico , Pirimidinas/uso terapéutico , Humanos , Piperidinas/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/farmacología
7.
Mar Biotechnol (NY) ; 22(6): 739-747, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32291549

RESUMEN

Glassin, a protein occluded in biosilica of the hexactinellid sponge Euplectela, promotes silica formation from silicic acid at room temperature and neutral pH and is characterized by its primary structure which consists of a tandem repeat carrying three distinct domains, histidine and aspartic acid-rich (HD) domain, proline-rich (P) domain, and histidine and threonine-rich (HT) domain. The present study aims to clarify the domain responsible for the promotion of silica formation and to demonstrate usefulness of glassin and its domain as a tag for purification and immobilization of recombinant proteins. When each domain was mixed with silicic acid at neutral pH, silica was formed with HD domain as well as glassin, or a single repeat, but not with P or HT domain. Neither of amino or carboxy-terminal half of HD domain induced silica formation. The amount of silica formed with HD domain was significantly lower than that of glassin or a single repeat. HD domain fused with HT domain raised the amount of silica formed, while a HD domain fused with P domain, a mixture of HD and P domains, or a mixture of HD and HT domains has little effect on the promotion of silica formation. Collectively, a minimum sequence for promotion of silica formation is HD domain, whose activity can be enhanced by HT domain through a topological effect. In addition, practicality of glassin and HD domain was demonstrated by fusion of these sequences to green fluorescent protein which was successfully purified with Ni affinity chromatography and immobilized on silica.


Asunto(s)
Poríferos/química , Proteínas/química , Dióxido de Silicio/química , Secuencia de Aminoácidos , Animales , Escherichia coli/genética , Glutatión Transferasa , Histidina/química , Proteínas Recombinantes/química , Ácido Silícico
8.
FEMS Microbiol Lett ; 367(7)2020 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-32239207

RESUMEN

Cellulosimicrobium sp. NTK2 (NTK2 strain) was isolated as a chitinolytic bacterium from mature compost derived from chitinous waste. The growth of the NTK2 strain was enhanced by supplementation of the culture medium with 2% crystalline chitin. Approximately 70% of the supplemented crystalline chitin was degraded during cultivation. Whole genome analysis of the NTK2 strain identified eight chitinases and two chitin-binding proteins. The NTK2 strain secreted two bacterial extracellular solute-binding proteins, three family 18 glycosyl hydrolases and one lytic polysaccharide monooxygenase specifically in the presence of crystalline chitin. A chitinolytic enzyme with a molecular mass of 29 kDa on SDS-PAGE under native conditions was also secreted. This chitinolytic enzyme exhibited the largest band upon zymography but could not be identified. In an attempt to identify all the chitinases secreted by the NTK2 strain, we expressed recombinant versions of the proteins exhibiting chitinolytic activity in Escherichia coli. Our results suggest that the 29 kDa protein belonging to family 19 glycosyl hydrolase was expressed specifically in the presence of 2% crystalline chitin.


Asunto(s)
Actinomycetales , Quitinasas , Actinomycetales/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Quitina/metabolismo , Quitinasas/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Oxigenasas de Función Mixta/genética
9.
Oncotarget ; 10(63): 6805-6815, 2019 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-31827723

RESUMEN

UL16-binding protein (ULBP) 1-6 and MHC class I chain-related molecule A and B (MICA/B) are NK group 2, member D (NKG2D) ligands, which are specifically expressed in infected or transformed cells and are recognized by NK cells via NKG2D-NKG2D ligand interactions. We previously reported that MICA/B overexpression predicted improved clinical outcomes in patients with resected non-small cell lung cancer (NSCLC). However, the clinicopathological features and prognostic significance of ULBPs in NSCLC remain unclear. Here,ULBP1-6 expression was evaluated based on immunohistochemistry of 91 NSCLC samples from patients following radical surgery. ULBPs were expressed by the majority of NSCLC. Either ULBP1 or ULBP2/5/6 overexpression was associated with squamous-cell carcinoma histology, whereas ULBP4 overexpression was associated with younger age and adenocarcinoma histology. Although overexpression of ULBP1-6 did not impact clinical outcomes in NSCLC patients, integrative profiling with cluster analysis classified patients into 3 subgroups based on the expression pattern of NKG2D ligands. The subgroup characterized by ULBP1 or ULBP2/5/6 high expressing but ULBP4 low expressing tumors showed poor overall survival. Taken together with previous results, NSCLC histological subtype strongly correlates with NKG2D ligands expression pattern. NKG2D ligands expression levels assessed by multiple immune parameters could predict clinical outcomes of patients with NSCLC.

10.
J Thorac Oncol ; 14(12): 2071-2083, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31449889

RESUMEN

INTRODUCTION: Programmed cell death-1 (PD-1) inhibitors effectively treat NSCLC and prolong survival. Robust biomarkers for predicting clinical benefits of good response and long survival with anti-PD-1 therapy have yet to be identified; therefore, predictive biomarkers are needed to select patients with benefits. METHODS: We conducted a prospective study to explore whether serum antibody against NY-ESO-1 and/or XAGE1 cancer-testis antigens predicted primarily good clinical response and secondarily long survival with anti-PD-1 therapy for NSCLC. The serum antibody was detected by enzyme-linked immunosorbent assay, and tumor immune microenvironment and mutation burden were analyzed by immunohistochemistry and next-generation sequencing. RESULTS: In the discovery cohort (n = 13), six antibody-positive NSCLC cases responded to anti-PD-1 therapy (two complete and four partial responses), whereas seven antibody-negative NSCLC cases did not. Antibody positivity was associated with good response and survival, regardless of tumor programmed death ligand 1 (PD-L1) expression, mutation burden, and CD8+ T-cell infiltration. In the validation cohort (n = 75), 17 antibody-positive NSCLC cases responded well to anti-PD-1 therapy as compared with 58 negative NSCLC cases (objective response rate 65% versus 19%, p = 0.0006) and showed significantly prolonged progression-free survival and overall survival. Antibody titers highly correlated with tumor reduction rates. In the multivariate analysis, response biomarkers were tumor programmed death ligand 1 expression and antibody positivity, and only antibody positivity was a significantly better predictive biomarker of progression-free survival (hazard ratio = 0.4, p = 0.01) and overall survival (hazard ratio = 0.2, p = 0.004). CONCLUSIONS: Our results suggest that NY-ESO-1 and/or XAGE1 serum antibodies are useful biomarkers for predicting clinical benefits in anti-PD-1 therapy for NSCLC and probably for other cancers.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Anciano , Carcinoma de Pulmón de Células no Pequeñas/microbiología , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Humanos , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Análisis de Supervivencia
11.
Oncol Rep ; 42(2): 839-848, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31173242

RESUMEN

Platinum­based chemotherapy improves the clinical outcome of patients with non­small cell lung cancer (NSCLC), although tumors often become refractory after treatment. Immunohistochemical staining was performed to investigate the expression levels of natural killer group 2 member D (NKG2D) ligands, programmed cell death­1 ligand 1 (PD­L1), and human leucocyte antigen (HLA)­class I in tissue samples collected from 10 NSCLC patients who received platinum­based chemotherapy followed by surgery. Additionally, the effects of repeated exposure to cisplatin on the expression of NKG2D ligands, PD­L1 and HLA­class I in NSCLC cell lines were assessed by flow cytometry. We found upregulation of PD­L1 or downregulation of NKG2D ligands in 5 of the 10 NSCLC cases, leading to the attenuation of NK cell­mediated tumor cell death. Moreover, upregulation of PD­L1 or downregulation of HLA­class I were observed in 6 cases, supporting tumor escape from T cell immunity. An in vitro assay showed that repeated exposure to cisplatin enhanced the expression of PD­L1 and NKG2D ligands in NSCLC cell lines. Notably, interferon gamma (IFNγ) stimuli enhanced PD­L1 expression while attenuated that of NKG2D ligands in NSCLC cell lines, which mimicked the results of the clinical study. Both IFNγ­induced upregulation of PD­L1 and downregulation of NKG2D ligands were blocked by the JAK­STAT inhibitor tofacitinib. These findings suggested that the expression levels of NKG2D ligands, PD­L1 and HLA­class I in residual tumors after chemotherapy were affected by host immunity, resulting in an immunoescape phenotype. Blocking IFNγ­induced tumor immunoescape by a JAK­STAT inhibitor might be a promising treatment strategy for NSCLC.


Asunto(s)
Antígeno B7-H1/metabolismo , Biomarcadores de Tumor/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Cisplatino/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Antígenos de Histocompatibilidad Clase I/metabolismo , Subfamilia K de Receptores Similares a Lectina de Células NK/metabolismo , Anciano , Antineoplásicos/farmacología , Apoptosis , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/patología , Proliferación Celular , Citotoxicidad Inmunológica/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Proteínas Ligadas a GPI/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Quinasas Janus/antagonistas & inhibidores , Células Asesinas Naturales/efectos de los fármacos , Ligandos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Piperidinas/farmacología , Pronóstico , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/farmacología , Pirroles/farmacología , Factores de Transcripción STAT/antagonistas & inhibidores , Células Tumorales Cultivadas
12.
Ther Clin Risk Manag ; 15: 605-612, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31118648

RESUMEN

Introduction: Numerous studies conducted until date have reported that the chemotherapy regimen could affect the programmed cell death ligand 1 (PD-L1) expression status in patients with non-small cell lung cancer (NSCLC). Materials and methods: A total of 36 NSCLC patients for whom both the surgically resected specimens of the primary tumors and re-biopsy specimens of the recurrent tumors were available were enrolled in this study. The PD-L1 expression status and tumor-infiltrating CD8-positive T lymphocytes (CD8+TILs) count were measured in paired samples by immunohistochemistry. The concordance rate in the tumor immune microenvironment (TIME) classification based on the PD-L1 expression status and CD8+TILs count was analyzed. Results: While the PD-L1 expression levels were similar between the surgical and re-biopsy specimens in 77.8% of cases, in 16.7% of cases, the expression levels were higher in the re-biopsy specimens. When the analysis was confined to patients who had received platinum-based chemotherapy, the percentage increased to 42.9%. The TIME classification changed in the re-biopsy specimens as compared to the surgical specimens in one-third of the patients, especially in those who had received chemotherapy previously. The TIME classification in the re-biopsy specimens more closely resembled that in the metastatic lymph nodes as compared to that in the primary tumor. Conclusion: In patients with recurrent NSCLC, especially those who have received chemotherapy previously, a recent re-biopsy sample is required to determine whether PD-1/PD-L1 inhibitors should be used for treatment or not.

13.
AME Case Rep ; 2: 43, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30506035

RESUMEN

Here, we report a patient with deciduoid type malignant pleural mesothelioma (MPM), which rapidly progressed. A 55-year-old man who might have been exposed to asbestos a few decades ago had severe back pain. The chest X-ray scanning and computed tomography (CT) revealed pleural thickness on his right thoracic space, without the presence of a lung mass. A pleural biopsy was performed and the patient was histologically diagnosed with deciduoid type MPM. Although he received two cycles of chemotherapy, his disease rapidly progressed and he died within two months of the diagnosis of deciduoid type MPM.

15.
Anticancer Res ; 38(8): 4637-4644, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30061230

RESUMEN

BACKGROUND/AIM: There is no clear evidence in the literature regarding the regulation of programmed cell death-ligand 1 (PD-L1) expression by cyclo-oxygenase-2 (COX2). In this study, whether PD-L1 expression was regulated by COX2 activity was examined in vitro. MATERIALS AND METHODS: Resected lung cancer specimens were analyzed for PD-L1 and COX2 expression by immunohistochemical analysis. Next, co-localization of PD-L1 and COX2 expression was analyzed by double-fluorescence staining. Lastly, the effect of COX2 inhibition on the expression of PD-L1 was examined using lung cancer cell lines. RESULTS: PD-L1 expression was significantly correlated with COX2 expression in the resected specimens. The majority of cancer cells that expressed PD-L1 also co-expressed COX2. However, treatment of lung cancer cell lines with a COX2 inhibitor had no impact on PD-L1 expression. CONCLUSION: Our results suggest that COX2 inhibition might have no effect on the usage of immune checkpoint inhibitors in lung cancer treatment.


Asunto(s)
Antígeno B7-H1/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Inhibidores de la Ciclooxigenasa 2/farmacología , Ciclooxigenasa 2/metabolismo , Neoplasias Pulmonares/tratamiento farmacológico , Células A549 , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Neoplasias Pulmonares/metabolismo
16.
Mol Biotechnol ; 60(9): 690-697, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30051300

RESUMEN

D-Stereospecific amidohydrolase (DAH) from Streptomyces sp. 82F2 has potential utility for the synthesis of D/L configuration dipeptides by an aminolysis reaction. Structural comparison of DAH with substrate-bound D-amino acid amidase revealed that three residues located in the active site pocket of DAH (Thr145, Ala267, and Gly271) might be involved in interactions with D-phenylalanine substrate. We substituted Ala267 and Gly271, which are located at the bottom of the hydrophobic pocket of DAH, with Phe and observed changes in the stereoselectivity and specific activity toward the free and acetylated forms of D/L-Phe-methyl esters. In contrast, the mutation of Thr145, which likely supplies negative charge for recognition of the amino group of the substrate, hardly affected the stereoselectivity of the enzyme. A similar effect was observed in an investigation of hydrolysis and aminolysis reactions using the acetylated forms of D/L-Phe-methyl esters and 1,8-diaminooctane as an acyl-donor and acyl-acceptor, respectively. Substrate binding by DAH was disrupted by the mutation of Ala267 to Val or Trp and kinetic analysis showed that the hydrophobicity of the bottom of the active site pocket (Ala267 and Gly271) is important for both stereoselectivity and recognition of hydrophobic substrates.


Asunto(s)
Amidohidrolasas/química , Secuencia de Aminoácidos/genética , Estereoisomerismo , Alanina/química , Amidohidrolasas/genética , Sustitución de Aminoácidos/genética , Sitios de Unión , Dominio Catalítico/genética , Hidrólisis , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Mutación , Fenilalanina/química , Especificidad por Sustrato
17.
Methods Enzymol ; 605: 429-455, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29909834

RESUMEN

Silicatein, a silica-synthesizing, catalytic triad hydrolase, was discovered in the silica spicules comprising the skeletons of certain marine sponges. Sequence similarity is closest to that of the mammalian cathepsin L, a catalytic triad hydrolase and protease. Genetic substitutions of residues in the catalytic triad, the predictive activities of polymeric and small-molecule analogs of the enzyme, and the wide range of structures accepted as substrates all support a reaction mechanism closely analogous to that established for the classical catalytic triad hydrolases. In this mechanism, hydrogen bonding of residues in the catalytic site is required to enhance nucleophilic attack and consequent hydrolysis of silicon alkoxide (and a wide range of other precursors), enabling subsequent polycondensation. Experimental and computational analyses revealed a novel pathway of self-assembly, in which the silicatein subunits first form a fractally patterned intermediate before entropic rearrangement to the hexagonally close-packed, macroscopic filament that serves both as the catalyst of silica synthesis in the sponge, and as a template guiding the deposition and emergent structure of the macroscopic silica filaments that form the sponge skeleton. Silicatein also proves capable of catalyzing the synthesis of organic silicones, metal oxides, metal phosphates, polylactides, and polymeric materials composed of organic metal compounds from their corresponding precursors, suggesting an evolutionary relaxation of structural substrate specificity that may have been necessary to accommodate the organic adducts of silicic acid suggested to comprise the natural precursor of the biogenic silica. Methods for purification, characterization, assay, and multiple uses of the enzyme are described.


Asunto(s)
Organismos Acuáticos/metabolismo , Catepsinas/metabolismo , Pruebas de Enzimas/métodos , Poríferos/metabolismo , Dióxido de Silicio/metabolismo , Animales , Biocatálisis , Biotecnología/métodos , Dominio Catalítico , Catepsinas/química , Catepsinas/aislamiento & purificación , Pruebas de Enzimas/instrumentación , Polímeros/metabolismo , Dominios Proteicos , Especificidad por Sustrato
18.
J Biosci Bioeng ; 126(3): 293-300, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29628267

RESUMEN

d-Stereospecific amidohydrolase from Streptomyces sp. 82F2 (DAH) recognizes d-amino acyl ester derivatives as substrates and catalyzes hydrolysis and aminolysis to yield d-amino acids and d-amino acyl peptides or amide derivatives, respectively. Crystallographic analysis has revealed that DAH possesses a large cavity with a small pocket at the bottom. Because the pocket is close to the catalytic center and is thought to interact with substrates, we examined the function of the eight residues that form the pocket in terms of substrate recognition and aminolysis via mutational analysis. Formation of the acyl-enzyme intermediate and catalysis of aminolysis by DAH were changed by substitutions of selected residues with Ala. In particular, I338A DAH exhibited a significant increase in the condensation product of Ac-d-Phe methyl ester and 1,8-diaminooctane (Ac-d-Phe-1,8-diaminooctane) compared with the wild-type DAH. A similar effect was observed by the mutation of Ile338 to Gly and Ser. The pocket shapes and local flexibility of the mutants I338G, I338A, and I338S are thought to resemble each other. Thus, changes in the shape and local flexibility of the pocket of DAH by mutation presumably alter substrate recognition for aminolysis.


Asunto(s)
Amidohidrolasas/química , Amidohidrolasas/metabolismo , Aminas/metabolismo , Dominio Catalítico , Streptomyces/enzimología , Aminas/química , Sitios de Unión , Catálisis , Dominio Catalítico/fisiología , Hidrólisis , Cinética , Estereoisomerismo , Streptomyces/metabolismo , Especificidad por Sustrato
19.
Biosci Biotechnol Biochem ; 82(7): 1107-1115, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29623768

RESUMEN

Family S9 prolyl oligopeptidases (POPs) are of interest as pharmacological targets. We recently found that an S9 POP from Pleurotus eryngii showed altered substrate specificity following H2O2 treatment. Oxidation of Met203 on the non-catalytic ß-propeller domain resulted in decreased activity toward non-aromatic aminoacyl-para-nitroanilides (pNAs) while maintaining its activity toward aromatic aminoacyl-pNAs. Given that the other Met residues should also be oxidized by H2O2 treatment, we constructed mutants in which all the Met residues were substituted with other amino acids. Analysis of the mutants showed that Met570 in the catalytic domain is another potent residue for the altered substrate specificity following oxidation. Met203 and Met570 lie on the surfaces of two different domains and form part of a funnel from the surface to the active center. Our findings indicate that the funnel forms the substrate pathway and plays a role in substrate recognition.


Asunto(s)
Metionina/metabolismo , Pleurotus/enzimología , Serina Endopeptidasas/metabolismo , Dominio Catalítico , Peróxido de Hidrógeno/química , Cinética , Mutagénesis Sitio-Dirigida , Oxidación-Reducción , Prolil Oligopeptidasas , Serina Endopeptidasas/química , Serina Endopeptidasas/genética , Especificidad por Sustrato
20.
Bioinspir Biomim ; 13(4): 041003, 2018 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-29620530

RESUMEN

Silk produced by the silkworm Bombyx mori is an attractive material because of its luster, smooth and soft texture, conspicuous mechanical strength, good biocompatibility, slow biodegradation, and carbon neutral synthesis. Silkworms have been domesticated and bred for production of better quality and quantity of silk, resulting in the development of sericulture and the textile industry. Silk is generally white, so dyeing is required to obtain colored fiber. However, the dyeing process involves harsh conditions and generates a large volume of waste water, which have environmentally and economically negative impacts. Although some strains produce cocoons that contain pigments derived from the mulberry leaves that they eat, the pigments are distributed in the sericin layer and are lost during gumming. In trials for production of colored silk by feeding silkworms on diets containing dyes, only limited species of dye molecules were incorporated into the silk threads. A method for the generation of transgenic silkworm was established in conjunction with the discovery of green fluorescent protein (GFP), and silkworms carrying the GFP gene spun silk threads that formed cocoons that glowed bright green and still retained the original properties of silk. A wide range of color variation of silk threads has been obtained by replacing the GFP gene with the genes of other fluorescent proteins chosen from the fluorescent protein palette. The genetically modified silk with photonic properties can be processed to form various products including linear threads, 2D fabrics, and 3D materials. The transgenic colored silk could be economically advantageous due to addition of a new value to silk and reduction of cost for water waste, and environmentally preferable for saving water. Here, I review the literature regarding the production methods of fluorescent silk from transgenic silkworms and present examples of genetically modified color silk.


Asunto(s)
Seda/química , Seda/genética , Animales , Animales Modificados Genéticamente , Materiales Biomiméticos/química , Biotecnología , Bombyx/química , Bombyx/genética , Color , Ingeniería Genética , Proteínas Fluorescentes Verdes/química , Proteínas Fluorescentes Verdes/genética , Proteínas Luminiscentes/química , Proteínas Luminiscentes/genética , Fenómenos Ópticos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética
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