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11.
Summary The sequence homology in the single copy DNA of sea stars has been measured. Labeled single copy DNA fromPisaster ochraceus was reannealed with excess genomic DNA fromP. brevispinus, Evasterias troschelii, Pycnopodia helianthoides, Solaster stimpsoni, andDermasterias imbricata. Reassociation reactions were performed under two criteria of salt and temperature. The extent of reassociation and thermal denaturation characteristics of hybrid single copy DNA molecules follow classical taxonomic lines.P. brevispinus DNA contains essentially all of the sequences present inP. ochraceus single copy tracer whileEvasterias andPycnopodia DNAs contain 52% and 46% of such sequences respectively. Reciprocal reassociation reactions with labeledEvasterias single copy DNA confirm the amount and fidelity of the sequence homology. There is a small definite reaction of uncertain homology betweenP. ochraceus single copy DNA andSolaster orDermasterias DNA. SimilarlySolaster DNA contains sequences homologous to approximately 18% ofDermasterias unique DNA. The thermal denaturation temperatures of heteroduplexes indicate that the generaPisaster andEvasterias diverged shortly after the divergence of the subfamilies Pycnopodiinae and Asteriinae. The twoPisaster species diverged more recently, probably in the most recent quarter of the interval since the separation of the generaPisaster andEvasterias. 相似文献
12.
J. Sherrod DeVerse Keith A. Bailey Greg A. Foster Vaishali Mittal Stuart M. Altman Scott I. Simon Anthony G. Passerini 《Journal of visualized experiments : JoVE》2012,(65)
Atherogenesis is potentiated by metabolic abnormalities that contribute to a heightened state of systemic inflammation resulting in endothelial dysfunction. However, early functional changes in endothelium that signify an individual''s level of risk are not directly assessed clinically to help guide therapeutic strategy. Moreover, the regulation of inflammation by local hemodynamics contributes to the non-random spatial distribution of atherosclerosis, but the mechanisms are difficult to delineate in vivo. We describe a lab-on-a-chip based approach to quantitatively assay metabolic perturbation of inflammatory events in human endothelial cells (EC) and monocytes under precise flow conditions. Standard methods of soft lithography are used to microfabricate vascular mimetic microfluidic chambers (VMMC), which are bound directly to cultured EC monolayers.1 These devices have the advantage of using small volumes of reagents while providing a platform for directly imaging the inflammatory events at the membrane of EC exposed to a well-defined shear field. We have successfully applied these devices to investigate cytokine-,2 lipid-3, 4 and RAGE-induced5 inflammation in human aortic EC (HAEC). Here we document the use of the VMMC to assay monocytic cell (THP-1) rolling and arrest on HAEC monolayers that are conditioned under differential shear characteristics and activated by the inflammatory cytokine TNF-α. Studies such as these are providing mechanistic insight into atherosusceptibility under metabolic risk factors. 相似文献
13.
Kristina M. Obom Andrew Magno Patrick J. Cummings 《Journal of visualized experiments : JoVE》2013,(79)
Fermentation systems are used to provide an optimal growth environment for many different types of cell cultures. The ability afforded by fermentors to carefully control temperature, pH, and dissolved oxygen concentrations in particular makes them essential to efficient large scale growth and expression of fermentation products. This video will briefly describe the advantages of the fermentor over the shake flask. It will also identify key components of a typical benchtop fermentation system and give basic instruction on setup of the vessel and calibration of its probes. The viewer will be familiarized with the sterilization process and shown how to inoculate the growth medium in the vessel with culture. Basic concepts of operation, sampling, and harvesting will also be demonstrated. Simple data analysis and system cleanup will also be discussed. 相似文献
14.
《Bioorganic & medicinal chemistry letters》2014,24(22):5330-5336
Free fatty acid receptor 1 (FFAR1) is a member of a previously characterized cluster of orphan G protein-coupled receptors (GPCRs). Later, this orphan receptor was identified as a target of medium- to long-chain free fatty acids in β-cells of the pancreas. Administration of FFAR1 agonists has been proved to potentiate glucose-stimulated insulin secretion from pancreatic β-cells. It was reported that some thiazolidinediones (TZDs), the best studied PPARγ agonists, are also able to stimulate FFAR1 in a dose-dependent manner. In the present study, a homology model of the human FFAR1 was constructed and inserted into a pre-equilibrated DPPC/TIP3P membrane system. This system was then simulated for 20 ns in complex with the FFAR1 agonist GW9085, as well as rosiglitazone and pioglitazone. We noticed that the salt bridge between Glu172 and Arg258 and the H bond between Glu145 and His153 could be responsible for the stabilization of the receptor in the inactive state. Moreover, we described for the first time the binding mode of TZDs in the binding site of FFAR1. The thiazolidinedione head forms a hydrogen bonding network with the critical polar residues in the binding site, Arg258 and Asn244, while the rest of the molecule is embedded into the receptor hydrophobic pocket. Based on this modeling study, we arrived at a proposal of the pharmacophore required for binding to both PPARγ and FFAR1. Insights gained from this investigation should provide future directions for the design of novel dual acting antidiabetic agents. 相似文献
15.
Dicoumarol derivatives were synthesized in the InCl3 catalyzed pseudo three-component reactions of 4-hydroxycoumarin with aromatic aldehydes in excellent yields. The reactions were performed in water under microwave irradiation. All synthesized compounds were characterized using NMR, IR, and UV–Vis spectroscopy, as well as with TD-DFT. Obtained dicoumarols were subjected to evaluation of their in vitro lipid peroxidation and soybean lipoxygenase inhibition activities. It was shown that five of ten examined compounds (3e, 3h, 3b, 3d, 3f) possess significant potential of antilipid peroxidation (84–97%), and that compounds 3b, 3e, 3h provided the highest soybean lipoxygenase (LOX-Ib) inhibition (IC50 = 52.5 µM) and 3i somewhat lower activity (IC50 = 55.5 µM). The bioactive conformations of the best LOX-Ib inhibitors were obtained by means of molecular docking and molecular dynamics. It was shown that, within the bioactive conformations interior to LOX-Ib active site, the most active compounds form the pyramidal structure made of two 4-hydroxycoumarin cores and a central phenyl substituent. This form serves as a spatial barrier which prevents LOX-Ib Fe2+/Fe3+ ion activity to generate the coordinative bond with the C13 hydroxyl group of the α-linoleate. It is worth pointing out that the most active compounds 3b, 3e, 3h and 3i can be candidates for further examination of their in vitro and in vivo anti-inflammatory activity and that molecular modeling study results provide possibility to screen bioactive conformations and elucidate the mechanism of dicoumarols anti-LOX activity. 相似文献
16.
A series of thirty (30) thiazole analogs were prepared, characterized by 1H NMR, 13C NMR and EI-MS and evaluated for Acetylcholinesterase and butyrylcholinesterase inhibitory potential. All analogs exhibited varied butyrylcholinesterase inhibitory activity with IC50 value ranging between 1.59 ± 0.01 and 389.25 ± 1.75 μM when compared with the standard eserine (IC50, 0.85 ± 0.0001 μM). Analogs 15, 7, 12, 9, 14, 1, 30 with IC50 values 1.59 ± 0.01, 1.77 ± 0.01, 6.21 ± 0.01, 7.56 ± 0.01, 8.46 ± 0.01, 14.81 ± 0.32 and 16.54 ± 0.21 μM respectively showed excellent inhibitory potential. Seven analogs 15, 20, 19, 24, 28, 30 and 25 exhibited good acetylcholinesterase inhibitory potential with IC50 values 21.3 ± 0.50, 35.3 ± 0.64, 36.6 ± 0.70, 44.81 ± 0.81, 46.36 ± 0.84, 48.2 ± 0.06 and 48.72 ± 0.91 μM respectively. All other analogs also exhibited well to moderate enzyme inhibition. The binding mode of these compounds was confirmed through molecular docking. 相似文献
17.
《Harmful algae》2014
Species of the PST producing planktonic marine dinoflagellate genus Alexandrium have been intensively scrutinised, and it is therefore surprising that new taxa can still be found. Here we report a new species, Alexandrium diversaporum nov. sp., isolated from spherical cysts found at two sites in Tasmania, Australia. This species differs in its morphology from all previously reported Alexandrium species, possessing a unique combination of morphological features: the presence of 2 size classes of thecal pores on the cell surface, a medium cell size, the size and shape of the 6″, 1′, 2⁗ and Sp plates, the lack of a ventral pore, a lack of anterior and posterior connecting pores, and a lack of chain formation. We determined the relationship of the two strains to other species of Alexandrium based on an alignment of concatenated SSU-ITS1, 5.8S, ITS2 and partial LSU ribosomal RNA sequences, and found A. diversaporum to be a sister group to Alexandrium leei with high support. A. leei shares several morphological features, including the relative size and shapes of the 6″, 1′, 2⁗ and Sp plates and the fact that some strains of A. leei have two size classes of thecal pores. We examined A. diversaporum strains for saxitoxin production and found them to be non-toxic. The species lacked sequences for the domain A4 of sxtA, as has been previously found for non-saxitoxin producing species of Alexandrium. 相似文献
18.
Dissipative particle dynamics (DPD) was carried out to study systems containing gold atoms, organic ether (oligohydroquinonyl ether terminated with a thiol group) and organic solvents. The components in the simulated system are very different in size and chemical nature. Our simulation showed that the reproduction of the macroscopic experimental phase separation, properly dividing the polymeric molecule into beads, selecting the size of gold bead, and choosing the appropriate interaction parameters between beads are crucial. In addition, the solvent effect was the dominant factor for the formation of spherical aggregates of Au atoms and organic ether molecules. We report the interaction strengths between the solvent and gold clusters. Our work has demonstrated that DPD methods can be applied to the study of complex meso-scale systems. 相似文献
19.
Analysis of the patterns and levels of diversity in duplicate gene not only traces evolutionary history of polyploids, but also provides insight into how the evolutionary process differs between lineages and between homoeologous loci within lineages. Elymus sensu lato is a group of allopolyploid species, which share a common St genome and with the different combinations of H, Y, P, and W genomes. To estimate the evolutionary process of the rbcL gene in species of Elymus s. l. and its putative dioploid relatives, 74 sequences were obtained from 21 species of Elymus s. l. together with 24 diploid taxa representing 19 basic genomes in Triticeae. Phylogeny and sequence diversity pattern analysis suggested that (1) species of Pseudoroegneria (Nevski) Á. Löve might serve as the maternal donor of the species of Elymus s. l; (2) differentiation of St genome were shown in the species of Elymus s. l. following polyploidy event; (3) divergences within the species might associate with geographic diversity and morphological variability; (4) differences in the levels and patterns of nucleotide diversity of the rbcL gene implied that the St genome lineages in the species of Elymus s. l. have differently evolutionary potentials. 相似文献
20.
Inhibition of α-glucosidase is an effective strategy for controlling the post-prandial hyperglycemia in diabetic patients. For the identification of new inhibitors of this enzyme, a series of new (R)-1-(2-(4-bromo-2-methoxyphenoxy) propyl)-4-(4-(trifluoromethyl) phenyl)-1H-1,2,3-triazole derivatives were synthesized (8a–d and 10a–e). The structures were confirmed by NMR, mass spectrometry and, in case of compound 8a, by single crystal X-ray crystallography. The α-glucosidase inhibitory activities were investigated in vitro. Most derivatives exhibited significant inhibitory activity against α-glucosidase enzyme. Their structure-activity relationship and molecular docking studies were performed to elucidate the active pharmacophore against this enzyme. Compound 10b was the most active analogue with IC50 value of 14.2 µM, while compound 6 was found to be the least active having 218.1 µM. A preliminary structure-activity relationship suggested that the presence of 1H-1,2,3-triazole ring in 1H-1,2,3-triazole derivatives is responsible for this activity and can be used as anti-diabetic drugs. The molecular docking studies of all active compounds were performed, in order to understand the mode of binding interaction and the energy of this class of compounds. 相似文献