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排序方式: 共有328条查询结果,搜索用时 31 毫秒
31.
T. Amanda Strom Serdar Durdagi Suha Salih Ersoz Ramin Ekhteiari Salmas Claudiu T. Supuran Andrew R. Barron 《Journal of peptide science》2015,21(12):862-870
A series of Fmoc‐Phe(4‐aza‐C60)‐OH of fullerene amino acid derived peptides have been prepared by solid phase peptide synthesis, in which the terminal amino acid, Phe(4‐aza‐C60)‐OH, is derived from the dipolar addition to C60 of the Fmoc‐Nα‐protected azido amino acids derived from phenylalanine: Fmoc‐Phe(4‐aza‐C60)‐Lys3‐OH ( 1 ), Fmoc‐Phe(4‐aza‐C60)‐Pro‐Hyp‐Lys‐OH ( 2 ), and Fmoc‐Phe(4‐aza‐C60)‐Hyp‐Hyp‐Lys‐OH ( 3 ). The inhibition constant of our fullerene aspartic protease PRIs utilized FRET‐based assay to evaluate the enzyme kinetics of HIV‐1 PR at various concentrations of inhibitors. Simulation of the docking of the peptide Fmoc‐Phe‐Pro‐Hyp‐Lys‐OH overestimated the inhibition, while the amino acid PRIs were well estimated. The experimental results show that C60‐based amino acids are a good base structure in the design of protease inhibitors and that their inhibition can be improved upon by the addition of designer peptide sequences. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
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Sam S Kucukasik F Yenigun O Nicolaus B Oner ET Yukselen MA 《Bioresource technology》2011,102(2):1788-1794
This study reports the first systematic investigation of the flocculation dynamics of exopolysaccharides (EPSs) produced by a halophilic bacterial strain grown on pretreated molasses as fermentation substrate. The potential use of these EPSs as an easily biodegradable, natural alternative for synthetic polyelectrolytes which are widely used and contain toxic and carcinogenic monomers was investigated. Flocculating activities of the EPS samples in synthetic water, synthetic sea water and natural sea water media which were used as model raw waters were monitored via the Photometric Dispersion Analyser (PDA 2000) instrument and removals were determined by measuring residual turbidities. One of the six EPS specimens, which formed the largest flocs thus performed highest turbidity removal, exhibited flocculation performance and particle removal efficiency comparable with commercial cationic, nonionic and anionic synthetic polyelectrolytes. 相似文献
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Durdagi S Şentürk M Ekinci D Balaydın HT Göksu S Küfrevioğlu Öİ Innocenti A Scozzafava A Supuran CT 《Bioorganic & medicinal chemistry》2011,19(4):1381-1389
Carbonic anhydrases (CAs, EC 4.2.1.1) are inhibited by sulfonamides, inorganic anions, phenols, coumarins (acting as prodrugs) and polyamines. A novel class of CA inhibitors (CAIs), interacting with the CA isozymes I, II (cytosolic) and IX, XII (transmembrane, tumor-associated) in a different manner, is reported here. Kinetic measurements allowed us to identify hydroxy-/methoxy-substituted benzoic acids as well as di-/tri-methoxy benzenes as submicromolar-low micromolar inhibitors of the four CA isozymes. Molecular docking studies of a set of such inhibitors within CA I and II allowed us to understand the inhibition mechanism. This new class of inhibitors binds differently compared to all other classes of inhibitors known to date: they were found between the phenol-binding site and the coumarin-binding site, filling thus the middle of the enzyme cavity. They exploit different interactions with amino acid residues and water molecules from the CA active site compared to other classes of inhibitors, offering the possibility to design CAIs with an interesting inhibition profile compared to the clinically used sulfonamides/sulfamates. 相似文献
34.
Serdar Oztora Osman Korkmaz Nezih Dagdeviren Yahya Celik Ayse Caylan Mehmet S Top Talip Asil 《BMC neurology》2011,11(1):103
Background
Migraine is a significant health problem, especially for the young people, due to its frequency and accompanying morbidity, causing disability and loss of performance. In this study, our aim was to determine the prevalence of migraine headaches among university students in Edirne, a Turkish city. 相似文献35.
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The flow of information through the epidermal growth factor receptor (EGFR) is shaped by molecular interactions in the plasma membrane. The EGFR is associated with lipid rafts, but their role in modulating receptor mobility and subsequent interactions is unclear. To investigate the role of nanoscale rafts in EGFR dynamics, we used single-molecule fluorescence imaging to track individual receptors and their dimerization partner, human epidermal growth factor receptor 2 (HER2), in the membrane of human mammary epithelial cells. We found that the motion of both receptors was interrupted by dwellings within nanodomains. EGFR was significantly less mobile than HER2. This difference was likely due to F-actin because its depolymerization led to similar diffusion patterns between the EGFR and HER2. Manipulations of membrane cholesterol content dramatically altered the diffusion pattern of both receptors. Cholesterol depletion led to almost complete confinement of the receptors, whereas cholesterol enrichment extended the boundaries of the restricted areas. Interestingly, F-actin depolymerization partially restored receptor mobility in cholesterol-depleted membranes. Our observations suggest that membrane cholesterol provides a dynamic environment that facilitates the free motion of EGFR and HER2, possibly by modulating the dynamic state of F-actin. The association of the receptors with lipid rafts could therefore promote their rapid interactions only upon ligand stimulation. 相似文献
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Alessio Innocenti Serdar Durdagi Nadjmeh Doostdar T. Amanda Strom Andrew R. Barron Claudiu T. Supuran 《Bioorganic & medicinal chemistry》2010,18(8):2822-2828
We investigated a series of derivatized fullerenes possessing alcohol, amine, and amino acid pendant groups as inhibitors of the zinc enzymes carbonic anhydrases (CAs, EC 4.2.1.1). We discovered that fullerenes bind CAs with submicromolar—low micromolar affinity, despite the fact that these compounds do not possess moieties normally associated with CA inhibitors such as the sulfonamides and their isosteres, or the coumarins. The 13 different mammalian CA isoforms showed a diverse inhibition profile with these compounds. By means of computational methods we assessed the inhibition mechanism as being due to occlusion of the active site entrance by means of the fullerene cage (possessing dimension of the same order of magnitude as the opening of the enzyme cavity, of 1 nm). The pendant moieties to the fullerene cage make interactions with amino acid residues from the active site, among which His64, His94, His96, Val121, and Thr200. Fullerenes thus represent a totally new class of nanoscale CA inhibitors which may show applications for targeting physiologically relevant isoforms, such as the dominant CA II and the tumor-associated CA IX. 相似文献
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