Chemistry / Kimya

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Access type: Open accessInstitution Author: search.filters.institutionAuthor.Şanlı Mohamed, Gülşah

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  • Article
    Citation - WoS: 1
    Citation - Scopus: 2
    Evaluation of in Vivo Biological Activity Profiles of Isoindole-1,3 Derivatives: Cytotoxicity, Toxicology, and Histopathology Studies
    (Amer Chemical Soc, 2023) Köse, Aytekin; Kaya, Meltem; Tomruk, Canberk; Uyanıkgil, Yiğit; Kıshalı, Nurhan; Kara, Yunus; Şanlı Mohamed, Gülşah
    The anticancer activity of N-benzylisoindole-1,3-dione derivatives was evaluated against adenocarcinoma (A549 Luc). First, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide activity assay studies of two isoindole-1,3-dione derivatives were performed against A549 cell lines. Both compounds showed inhibitory effects on the viability of A549 cells. Then, we explored the potential of these compounds as active ingredients by in vivo studies. Nude mice were given A549-luc lung cancer cells, and tumor growth was induced with a xenograft model. Then, nude mice were divided into three groups: the control group, compound 3 group, and compound 4 group. After application of each compound to the mice, tumor sizes, their survival, and weight were determined for 60 days. Furthermore, toxicological studies were performed to examine the effects of the drugs in mice. In addition to toxicological studies, histopathological analyses of organs taken from mice were performed, and the results were evaluated. The obtained results showed that both N-benzylisoindole derivatives are potential anticancer agents.
  • Article
    Citation - WoS: 21
    Citation - Scopus: 23
    Engineering of Xylanases for the Development of Biotechnologically Important Characteristics
    (Wiley, 2023) Sürmeli, Yusuf; Şanlı Mohamed, Gülşah
    Xylanases are the main biocatalysts used for the reduction of the xylan backbone from hemicellulose, randomly splitting off β-1,4-glycosidic linkages between xylopyranosyl residues. Xylanase market has been annually estimated at 500 million US Dollars and they are potentially used in broad industrial process ranges such as paper pulp biobleaching, xylo-oligosaccharide production, and biofuel manufacture from lignocellulose. The highly stable xylanases are preferred in the downstream procedure of industrial processes because they can tolerate severe conditions. Almost all native xylanases can not endure adverse conditions thus they are industrially not proper to be utilized. Protein engineering is a powerful technology for developing xylanases, which can effectively work in adverse conditions and can meet requirements for industrial processes. This study considered state-of-the-art strategies of protein engineering for creating the xylanase gene diversity, high-throughput screening systems toward upgraded traits of the xylanases, and the prediction and comprehensive analysis of the target mutations in xylanases by in silico methods. Also, key molecular factors have been elucidated for industrial characteristics (alkaliphilic enhancement, thermal stability, and catalytic performance) of GH11 family xylanases. The present review explores industrial characteristics improved by directed evolution, rational design, and semi-rational design as protein engineering approaches for pulp bleaching process, xylooligosaccharides production, and biorefinery & bioenergy production.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Structural and Functional Analyses of Gh51 Alpha-L of Geobacillus Vulcani Gs90 Reveal Crucial Residues for Catalytic Activity and Thermostability
    (Wiley, 2022) Sürmeli, Yusuf; Şanlı Mohamed, Gülşah
    Alpha-L-arabinofuranosidase (Abf) is of big interest in various industrial areas. Directed evolution is a powerful strategy to identify significant residues underlying Abf properties. Here, six active variants from GH51 Abf of Geobacillus vulcani GS90 (GvAbf) by directed evolution were overproduced, extracted, and analyzed at biochemical and structural levels. According to the activity and thermostability results, the most-active and the least-active variants were found as GvAbf51 and GvAbf52, respectively. GvAbf63 variant was more active than parent GvAbf by 20% and less active than GvAbf51. Also, the highest thermostability belonged to GvAbf52 with 80% residual activity after 1 h. Comparative sequence and structure analyses revealed that GvAbf51 possessed L307S displacement. Thus, this study suggested that L307 residue may be critical for GvAbf activity. GvAbf63 had H30D, Q90H, and L307S displacements, and H30 was covalently bound to E29 catalytic residue. Thus, H30D may decrease the positive effect of L307S on GvAbf63 activity, preventing E29 action. Besides, GvAbf52 possessed S215N, L307S, H473P, and G476C substitutions and S215 was close to E175 (acid–base residue). S215N may partially disrupt E175 action. Overall effect of all substitutions in GvAbf52 may result in the formation of the C–C bond between C171 and C213 by becoming closer to each other.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 7
    Regio- and Stereo-Chemical Ring-Opening Reactions of the 2,3-Epoxy Alcohol Derivative With Nucleophiles: Explanation of the Structures and C-2 Selectivity Supported by Theoretical Computations
    (Elsevier, 2022) Gündoğdu, Özlem; Atalay, Abdurrahman; Çelebioğlu, Neslihan; Anıl, Barış; Şahin, Ertan; Şanlı Mohamed, Gülşah; Bozkaya, Uğur; Kara, Yunus
    The ring-opening reactions of (1aS,2S,6bR)-5-ethyl-2-hydroxyhexahydro-4H-oxireno[2,3-e]isoindole-4,6(5H)-dione were investigated under very mild and nonchelated conditions. C-2 selective ring-opening products were obtained with nucleophilic additions such as Cl−, Br− and N3−. The exact configuration of (3aS,4R,5R,6S,7aS)-5-chloro-2-ethyl-4,6-dihydroxyhexahydro-1H-isoindole-1,3(2H)-dione was determined by X-Ray diffraction analysis which was obtained from the reaction of epoxy alcohol with HCl. On the other hand, theoretical computations were carried out to explain the regioselectivity in the ring opening reaction of epoxy alcohols. The results showed that the ring-opening reaction of both epoxy alcohols proceeds in a kinetically controlled manner and regioselectivity occurs depending on the transition state.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 8
    Thermoalkalophilic Recombinant Esterase Entrapment in Chitosan/Calcium Beads and Its Characterization
    (Wiley, 2021) Tercan, Cisem; Sürmeli, Yusuf; Şanlı Mohamed, Gülşah
    BACKGROUND Esterases (EC 3.1.1.1), a class of hydrolases, degrade the ester bonds of lipids into alcohol and carboxylic acids and synthesize carboxylic ester bonds. They are used in a variety of biotechnological, industrial, environmental, and pharmaceutical applications due to their many valuable properties. Particularly, extremophilic esterases with many superior properties are of great interest for various reactions. Immobilization of enzymes may provide some advantages over free enzymes not only to improve the properties of enzymes but also to increase the reusability of biocatalyst in industrial applications. Therefore, many different immobilization applications for enzymes have been reported in various studies. To our knowledge, a thermophilic esterase has not so far been immobilized by entrapment using chitosan/calcium/alginate-blended beads. Here, we reported the immobilization of thermoalkalophilic recombinant esterase by entrapment using chitosan/calcium/alginate-blended beads, and then the entrapped esterase was characterized biochemically in details. RESULTS In the present study, a thermophilic recombinant esterase was immobilized by entrapment in chitosan/calcium/alginate-blended beads for the first time. The 0.5 mg mL(-1) purified recombinant esterase was entrapped in 1% chitosan, 2% alginate, and 0.7 M CaCl2 blended beads. The results showed that immobilization yield and entrapment efficiency of the entrapped esterase were 69.5% and 80.4%, respectively. SEM micrograph showed that the surface of the beads resembled a mesh and very compact structures. Chitosan/calcium/alginate-blended beads exhibited an 18.8% swelling ratio and had a moderate porous structure. The entrapment technique highly enhanced the thermostability of the esterase and shifted its optimum temperature from 65 to 80 degrees C. The immobilized esterase was very stable in a wide range of pH (8.5-11) displaying maximum activity at pH 9. ZnCl2 slightly increased the activity of immobilized esterase whereas several metal ions reduced the enzyme activity. When the enzyme was immobilized in chitosan/calcium/alginate-blended beads, its K-m increased about 2 times and V-max value decreased almost 1.5 times. Immobilization allowed repeated uses of the esterase having good operational stability in a continuous process. CONCLUSION The results revealed that the immobilization of a thermophilic recombinant esterase by entrapment in chitosan/calcium/alginate-blended beads exhibited considerably better compared to other immobilization processes with various entrapment strategies. (c) 2021 Society of Chemical Industry (SCI).
  • Article
    Citation - WoS: 39
    Citation - Scopus: 44
    Identification and Characterization of Novel Thermostable Alpha-Amylase From Geobacillus Sp. Gs33
    (Elsevier, 2020) Burhanoğlu, Tülin; Sürmeli, Yusuf; Şanlı Mohamed, Gülşah
    In 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: 8
    Citation - Scopus: 10
    Trypsin-Immobilized Silica: a Novel Adsorbent for V(iv) and V(v) Removal From Water
    (Water Environment Federation, 2018) Erdem Yayayürük, Aslı; Shahwan, Talal; Şanlı Mohamed, Gülşah; Eroğlu, Ahmet Emin
    In the present study, trypsin-immobilized silica was employed for the removal of V(IV) and V(V) ions from water. The synthesized sorbent was first characterized and then investigated for the removal of V(IV) and V(V) under various experimental conditions. The adsorption performance of the sorbent was tested as a function of pli, sorbent amount, initial vanadium concentration, contact time, and temperature. The sorption process was then investigated, both from a kinetic perspective and also in terms of isotherm models. The Langmuir adsorption isotherm was the best model to describe the sorption process. Sorption thermodynamics were spontaneous and exothermic. The proposed method was successfully applied to real samples for the removal of V(IV)and V(V) with sufficient accuracy and precision.
  • Article
    Citation - WoS: 15
    Citation - Scopus: 17
    Improved 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, Gülşah
    alpha-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.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 13
    Synthesis and Biological Evaluation of New Chloro/Acetoxy Substituted Isoindole Analogues as New Tyrosine Kinase Inhibitors
    (Academic Press, 2020) Köse, Aytekin; Kaya, Meltem; HorasanKishalı, Nurhan; Akdemir, Atilla; Şahin, Ertan; Kara, Yunus; Şanlı Mohamed, Gülşah
    We have developed a versatile synthetic approach for the synthesis of new isoindole derivatives via the cleavage of ethers from tricyclic imide skeleton compounds. An exo-cycloadduct prepared from the Diels-Alder reaction of furan and maleic anhydride furnished imide derivatives. The epoxide ring was opened with Ac2O or Ac2O/AcCl in the presence of a catalytic amount of H2SO4 in order to yield new isoindole derivatives 8a-d and 9a-d. The anticancer activity of these compounds was evaluated against the HeLa cell lines. The synthesized compounds showed inhibitory effects on the viability of HeLa cells and the degree of cytotoxicity was increased with the level of bigger branched isoindole derivatives. To better understand the acting mechanism of these molecules, western blot analysis was performed with using mTOR and its downstream substrates. In addition, human mTOR and ribozomal S6 kinase beta 1 (RS6K beta 1) have been investigated with molecular modelling studies as possible targets for compound series 8 and 9.
  • Article
    Citation - WoS: 18
    Citation - Scopus: 23
    A Thermophilic ?-L From Geobacillus Vulcani Gs90: Heterologous Expression, Biochemical Characterization, and Its Synergistic Action in Fruit Juice Enrichment
    (Springer, 2018) İlgü, Hüseyin; Sürmeli, Yusuf; Şanlı Mohamed, Gülşah
    α-l-Arabinofuranosidases with an orchestral action of xylanolytic enzymes degrades the xylan in plant cell wall. In this study, heterologous expression, biochemical characterization, and synergistic action of α-l-Arabinofuranosidase from previously identified.Geobacillus vulcani GS90 (GvAbf) was investigated. The recombinant α-l-Arabinofuranosidase was overexpressed in Escherichia coli BL21 (λDE) and purified via His-tag Ni-affinity and size-exclusion chromatography. Optimum activity of the purified α-l-Arabinofuranosidase was obtained at pH 5 and at 70 °C. The GvAbf was active in a broad pH and temperature ranges; pH 4–9 and 30–90 °C, respectively. In addition, it retained most of its activity after an hour incubation at 70 °C and remained relatively stable at pH 3–6. GvAbf was quite stable against various metal ions. The kinetic parameters of GvAbf was obtained as Vmax and Km; 200 U/mg and 0.2 mM with p-nitrophenyl-α-l-arabinofuranoside and 526 U/mg and 0.1 mM with sugar beet arabinan, respectively. The synergistic action of GvAbf was studied with commercially available xylanase on juice enrichment of apples, grapes, oranges, and peaches. The best juice enrichment in terms of clarity, reducing sugar content, and yield, was achieved with GvAbf and xylanase together compared to treatment with xylanase and GvAbf alone in all fruits. The treatment with GvAbf and xylanase together lead to an increased juice yield by 26.56% (apple), 30.88% (grape), 40.00% (orange) and 32.20% (peach) as well as having a significant effect on juice clarity by an increase of % transmittance 47.26, 25.98, 41.77, and 44.97, respectively. The highest reducing sugar level of fruit juices also obtained with GvAbf and xylanase together compared to treatment with xylanase and GvAbf alone in all types of fruits. GvAbf and xylanase together as simultaneous synergistic manner may have an exciting potential for application in fruit juice processing.