PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Citation - WoS: 17Citation - Scopus: 15Antiproliferative and Apoptotic Effects of Olive Leaf Extract Microcapsules on Mcf-7 and A549 Cancer Cells(American Chemical Society, 2023) Bal, Yıldız; Sürmeli, Yusuf; Şanlı Mohamed, GülşahAlginate microcapsules are a talented means for the delivery of broad curative biomacromolecules. In this study, we immobilized olive leaf extract (OLE) by calcium alginate (CA) and chitosan-coated CA (CCA) and characterized the OLE-loaded CA and CCA. The cytotoxic effect, the cell cycle arrest, and the apoptotic effect of OLE and its microcapsules were investigated against breast adenocarcinoma (MCF-7) and lung carcinoma (A549). As a result, the loading capacity of OLE-CA and OLE-CCA was found to be 80 and 99%, respectively, in optimal conditions. Also, OLE-CA and OLE-CCA were characterized by unique FTIR peaks and morphological display relative to the empty CCA microcapsules. The cytotoxicity analysis showed that the IC50 values of OLE-CA and OLE-CCA were determined to be 312 and 0.94 μg mL-1 against A549, respectively, whereas these were found to be 865.4 and 425.5 μg mL-1 for MCF-7 cells. On the other hand, the OLE microcapsules did not possess in any concentration of cytotoxic influence on the BEAS 2B healthy cell line. Also, the exposure of OLE-CCA to MCF-7 and A549 resulted in the arrest of more MCF-7 and A549 cells at the G0/G1 phase compared to the OLE. A549 and MCF-7 cells were predominantly found in the late apoptosis phase and necrosis phase, respectively. Optical microscopy images confirmed that OLE microcapsules were more effective against MCF-7 and A549 than free OLE. The present work suggested that the OLE microcapsules might be administered as nutrition supplements for cancer therapy. © 2023 The Authors. Published by American Chemical Society.Article Citation - WoS: 2Citation - Scopus: 6Immobilization of Olive Leaf Extract With Chitosan Nanoparticles as an Adjunct To Enhance Cytotoxicity(American Chemical Society, 2023) Özdamar, Burcu; Sürmeli, Yusuf; Şanlı Mohamed, GülşahWe immobilized the olive leaf extract (OLE) with chitosannanoparticles(CNPs) by optimizing the effect of various immobilization conditions,and OLE-loaded CNPs (OLE-CNPs) were then elaborately characterizedphysicochemically by scanning electron microscopy (SEM), Fourier transforminfrared (FT-IR) spectroscopy, dynamic light scattering (DLS), andatomic force microscopy (AFM). Under optimal conditions, CNPs wereable to accommodate the OLE with a loading capacity of 97.5%. Theresulting OLE-CNPs had a spherical morphology, and their average diameterwas approximately 100 nm. The cytotoxic influence, cell cycle distribution,and apoptosis stage of OLE and OLE-CNPs were analyzed on lung carcinoma(A549) and breast adenocarcinoma (MCF-7) cell lines. In an in vitrocytotoxic assay, IC50 values of OLE-CNPs were determinedto be 540 & mu;g/mL for A549 and 810 & mu;g/mL for MCF-7. Thetreatment of both A549 and MCF-7 with OLE-CNPs caused the highestcell arrest in G0/G1 in a dose-independent manner. OLE-CNPs affectedcell cycle distribution in a manner different from free OLE treatmentin both cancer cells. A549 and MCF-7 cells were predominantly foundin the late apoptosis and necrosis phases, respectively, upon treatmentof 1000 & mu;M OLE-CNPs. Our results suggest that CNPs enhance theutility of OLEs as nutraceuticals in cancer and that OLE-CNPs canbe utilized as an adjunct to cancer therapy.Article Citation - WoS: 16Citation - Scopus: 18A Novel Thermostable Xylanase From Geobacillus Vulcani Gs90: Production, Biochemical Characterization, and Its Comparative Application in Fruit Juice Enrichment(Wiley, 2021) Algan, Müge; Sürmeli, Yusuf; Şanlı Mohamed, GülşahXylanases have great attention to act as a potential role in agro-industrial processes. In this study, production, characterization, and fruit juice application of novel xylanase from thermophilic Geobacillus vulcani GS90 (GvXyl) were performed. GvXyl was purified via acetone precipitation and gel-filtration chromatography. The results showed that GvXyl had 1,671.4 U/mg of specific activity and optimally worked at pH 8 and 55 degrees C. It was also active in a wide pH (3-9) and temperature (30-90oC) ranges. GvXyl was highly stable at 90oC and relatively stable at pH 3-9. The kinetic parameters of GvXyl were obtained as K-m, V-max, and k(cat); 10.2 mg/ml, 4,104 mu mol min(-1) mg(-1), and 3,542.6 s(-1), respectively. GvXyl had higher action than commercial xylanase in fruit juice enrichment. These results revealed that GvXyl might possess a potential influence in fruit juice processing because of its high specific activity and great thermal stability. Practical applications Polysaccharides include starch, pectin, and hemicellulose create problems by lowering fruit juice quality in beverages. To overcome this problem, various clarification processes might be applied to natural fruit juices. Even though chemicals are widely used for this purpose, recently enzymes including xylanases are preferred for obtaining high-quality products. In this study, we reported the production and biochemical characterization of novel thermostable xylanase from thermophilic G. vulcani GS90 (GvXyl). Also, apple and orange juice enrichment were performed with the novel xylanase to increase the quality in terms of yield, clarity, and reducing sugar substance. The improved quality features of apple and orange juices with GvXyl was then compared to commercially available beta-1,4-xylanase. The results revealed that GvXyl might possess a potential influence in fruit juice processing because of its high specific activity and great thermal stability.Article Citation - WoS: 11Citation - Scopus: 16Purification and Biochemical Characterization of a Novel Thermostable Serine Protease From Geobacillus Sp. Gs53(Springer, 2021) Şanlı Mohamed, Gülşah; Güracar Baykara, Seden; Sürmeli, YusufProteases account for approximately 60% of the enzyme market in the world, and they are used in various industrial applications including the detergent industry. In this study, production and characterization of a novel serine protease of thermophilic Geobacillus sp. GS53 from Balcova geothermal region, Izmir, Turkey, were performed. The thermostable protease was purified through ammonium sulfate precipitation and anion-exchange chromatography. The results showed that the protease had 137.8 U mg(-1) of specific activity and optimally worked at 55 C-o and pH 8. It was also active in a broad pH (4-10) and temperature (25-75 degrees C) ranges. The protease was highly stable at 85 degrees C and demonstrated relative stability at pH 4, 7, and 10. Also, the enzyme had high stability against organic solvents and surfactants; enzyme relative activity did not decrease below 81% upon preincubation for 10 min. Ca2+, Cu2+, and Zn2+ ions slightly induced protease activity. The protease was highly specific to casein, skim milk, Hammerstein casein, and BSA substrates. These results revealed that the protease might have a potential effect in a variety of industrial fields, especially the detergent industry, because of its high thermostability and stability to surfactants.Article Citation - WoS: 39Citation - Scopus: 44Identification and Characterization of Novel Thermostable Alpha-Amylase From Geobacillus Sp. Gs33(Elsevier, 2020) Burhanoğlu, Tülin; Sürmeli, Yusuf; Şanlı Mohamed, GülşahIn this study, the heterologous expression and biochemical characterization of a thermostable alpha-amylase from Geobacillus sp. GS33 was investigated. The recombinant alpha-amylase was overexpressed in Escherichia coli BL21 (lambda DE) and purified via anion exchange and size-exclusion chromatography. The purified alpha-amylase had a molecular weight of about 60 kDa, and was active in a broad range of pH 3-10 and temperature (40-90 degrees C) withmaximumactivity at pH 7-8 and 60 degrees C. The enzyme retained 50% residual activity at 65 degrees C, but only 20% at 85 degrees C after 16 h. At pH 9 and pH 7, the residual activity at 65 degrees C was 50% and 30%, respectively. The enzymewas remarkably activated by Co2+, Ca2+, Mg2+, PMSF, DTT, and Triton X-100, but partially inhibited by Cu2+, methanol, hexane, ethanol, acetone, SDS, and Tween 20. A molecular phylogeny analysis showed that the enzyme's amino acid sequence had the closest connection with an alpha-amylase from Geobacillus thermoleovorans subsp. stromboliensis nov. 3D-structure-based amino acid sequence alignments revealed that the three catalytic residues (D217, E246, D314) and the four Ca2+ ion coordination residues (N143, E177, D186, H221) were conserved in alpha-amylase from Geobacillus sp. GS33. The temperature stability and neutral pH optimum suggest that the enzyme may be useful for industrial applications. (C) 2020 Elsevier B.V. All rights reserved.Article Citation - WoS: 15Citation - Scopus: 17Improved Activity of Alpha-L From Geobacillus Vulcani Gs90 by Directed Evolution: Investigation on Thermal and Alkaline Stability(John Wiley and Sons Inc., 2019) Sürmeli, Yusuf; İlgü, Hüseyin; Şanlı Mohamed, Gülşahalpha-L-Arabinofuranosidase (Abf) is a potential enzyme because of its synergistic effect with other hemicellulases in agro-industrial field. In this study, directed evolution was applied to Abf from Geobacillus vulcani GS90 (GvAbf) using one round error-prone PCR and constructed a library of 73 enzyme variants of GvAbf. The activity screening of the enzyme variants was performed on soluble protein extracts using p-nitrophenyl alpha-L-arabinofuranoside as substrate. Two high activity displaying variants (GvAbf L307S and GvAbf Q90H/L307S) were selected, purified, partially characterized, and structurally analyzed. The specific activities of both variants were almost 2.5-fold more than that of GvAbf. Both GvAbf variants also exhibited higher thermal stability but lower alkaline stability in reference to GvAbf. The structural analysis of GvAbf model indicated that two mutation sites Q90H and L307S in both GvAbf variants are located in TIM barrel domain, responsible for catalytic action in many Glycoside Hydrolase Families including GH51. The structure of GvAbf model displayed that the position of L307S mutation is closer to the catalytic residues of GvAbf compared with Q90H mutation and also L307S mutation is conserved in both variants of GvAbf. Therefore, it was hypothesized that L307S amino acid substitution may play a critical role in catalytic activity of GvAbf. (C) 2018 International Union of Biochemistry and Molecular Biology, Inc.