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91.
Kent Langel Staffan Lindberg Dana Copolovici Piret Arukuusk Rannar Sillard Űlo Langel 《International journal of peptide research and therapeutics》2010,16(4):247-255
Cell-penetrating peptides (CPPs) are able to efficiently internalize into cells and can therefore be used as vectors for non-viral
cellular delivery of different cargoes. Previous studies have shown that hydrophobic modifications of different CPPs can increase
their transfection efficiency dramatically. In this study we have modified the cell penetrating-peptide transportan 10 (TP10)
with a variety of hydrophobic molecules to determine the role of hydrophobicity in the uptake of these molecules. The results
can be used to synthesize more efficient delivery vectors. To evaluate how these constructs are able to transport cargoes
into cells we used 2′-OMe splice correcting oligonucleotides. Non-covalent peptide-cargo complexes were formed and their transfection
efficiency was measured using a luciferase readout system. The hydrophobicity of the novel modifications was correlated with
their biological efficacy. We determined the most efficient range of hydrophobicity for TP10 analogs for delivering oligonucleotides
into cells. In order to assess how the transfection efficacy of these particles is dependent on their size the hydrodynamic
diameter of the formed nanoparticles was measured using dynamic light scattering. These findings will be used to develop highly
efficient non-viral gene therapy vectors. 相似文献
92.
Bj?rn?DueholmEmail authorView authors OrcID profile David?Bruce Philip?Weinstein Susan?Semple Birger?Lindberg?M?ller Jacob?Weiner 《Plant Ecology》2017,218(2):185-196
Root hemiparasitic plants take up resources from the roots of neighbouring plants, which they use for fuelling their own growth. While taking up resources from the hosts below-ground, they may simultaneously compete with the hosts for sunlight. Suppression caused by the parasitism could result in openings in the vegetation structure and increased mortality levels. On the other hand, the root hemiparasites may also be constrained by the hosts, restricting the parasites to a limited number of locations within a community. These vegetation alterations and location restrictions can be referred to as spatial signatures of the root hemiparasites. In order to search for such spatial signatures, we investigated a population of a predominant Acacia species in Australia co-occurring with established root hemiparasitic shrubs, using intensity estimates of the Acacia and dead shrubs to be indicators of parasite populations. We find evidence that the root hemiparasitic shrubs, like herbaceous root hemiparasites, prefer growing at distances from neighbouring plants that fulfil resource requirements both below-ground and above-ground. Assuming that root hemiparasites are limited by their hosts, we present an optimal host density and distance to host hypothesis (‘Goldilocks hypothesis’) to account for such a vegetation pattern. Although mortality appeared to primarily result from intraspecific competition and shoot parasitism, the root parasitism could explain some of the mortality in open areas. It is likely that both processes occur simultaneously. In spite of differing annual and perennial life strategies among root hemiparasites, root parasitism across systems may follow these two general processes in the formation of vegetation patterns. 相似文献
93.
Transformation of Staphylococcus aureus cells with circular duplex deoxyribonucleic acid prepared from plasmid-carrying strains by alkali denaturation and selective renaturation or by dye-buoyant density centrifugation is reported. In all of the transformants tested, the transformed markers became established as autonomous plasmids that were biologically and physically indistinguishable from those carried by the donor strains. Transformation with bulk deoxyribonucleic acid from a strain carrying the penicillinase plasmid, PI(258), gave rise to transformants in which the erythromycin locus, the only plasmid marker transformed, was shown to be integrated into the host chromosome. 相似文献
94.
Cloning and expression of the gene for a fibronectin-binding protein from Staphylococcus aureus. 总被引:31,自引:3,他引:31 下载免费PDF全文
J I Flock G Frman K Jnsson B Guss C Signs B Nilsson G Raucci M Hk T Wadstrm M Lindberg 《The EMBO journal》1987,6(8):2351-2357
The gene encoding the fibronectin-binding protein (FNBP) from Staphylococcus aureus strain 8325-4 was isolated from a gene bank in pBR322. The original clone, containing a 6.5-kb insert, gave a functional product present in the periplasm of Escherichia coli. Analysis of polypeptides isolated after affinity chromatography on fibronectin-Sepharose followed by ion-exchange chromatography revealed two gene products, 87 and 165 kd in mol. wt. The amino acid compositions of these two polypeptides and a native FNBP from S. aureus strain Newman were very similar. Antibodies raised against the native FNBP from strain Newman precipitated the 125I-labelled 165-kd polypeptide, and unlabeled 165- and 87-kd polypeptides as well as native FNBP inhibited the immunoprecipitation reactions. The region of the fnbp-gene encoding the fibronectin-binding activity has been identified and subcloned in an expression vector based on the staphylococcal protein A gene. The resulting product in E. coli is an extracellular fusion protein consisting of two IgG-binding domains of protein A followed by a fibronectin-binding region. The fusion protein binds to fibronectin and completely inhibits the binding of fibronectin to intact cells of S. aureus. 相似文献
95.
96.
Mohammed A. Kader Sylvia Lindberg Thorsten Seidel Dortje Golldack Vladislav Yemelyanov 《Physiologia plantarum》2007,130(1):99-111
Perception of salt stress in plant cells induces a change in the free cytosolic Ca2+, [Ca2+]cyt, which transfers downstream reactions toward salt tolerance. Changes in cytosolic H+ concentration, [H+]cyt, are closely linked to the [Ca2+]cyt dynamics under various stress signals. In this study, salt‐induced changes in [Ca2+]cyt, and [H+]cyt and vacuolar [H+] concentrations were monitored in single protoplasts of rice (Oryza sativa L. indica cvs. Pokkali and BRRI Dhan29) by fluorescence microscopy. Changes in cytosolic [Ca2+] and [H+] were detected by use of the fluorescent dyes acetoxy methyl ester of calcium‐binding benzofuran and acetoxy methyl ester of 2′, 7′‐bis‐(2‐carboxyethyl)‐5‐(and‐6) carboxyfluorescein, respectively, and for vacuolar pH, fluorescent 6‐carboxyfluorescein and confocal microscopy were used. Addition of NaCl induced a higher increase in [Ca2+]cyt in the salt‐tolerant cv. Pokkali than in the salt‐sensitive cv. BRRI Dhan29. From inhibitor studies, we conclude that the internal stores appear to be the major source for [Ca2+]cyt increase in Pokkali, although the apoplast is more important in BRRI Dhan29. The [Ca2+]cyt measurements in rice also suggest that Na+ should be sensed inside the cytosol, before any increase in [Ca2+]cyt occurs. Moreover, our results with individual mesophyll protoplasts suggest that ionic stress causes an increase in [Ca2+]cyt and that osmotic stress sharply decreases [Ca2+]cyt in rice. The [pH]cyt was differently shifted in the two rice cultivars in response to salt stress and may be coupled to different activities of the H+‐ATPases. The changes in vacuolar pH were correlated with the expressional analysis of rice vacuolar H+‐ATPase in these two rice cultivars. 相似文献
97.
Shishova M Yemelyanov V Rudashevskaya E Lindberg S 《Journal of plant physiology》2007,164(10):1323-1330
The auxin-induced changes in cytosolic concentrations of Ca(2+) and H(+) ions were investigated in protoplasts from maize coleoptile cells at 3rd, 4th and 5th day of development of etiolated seedlings. The shifts in [Ca(2+)](cyt) and [H(+)](cyt) were detected by use of fluorescence microscopy in single protoplasts loaded with the tetra[acetoxymethyl]esters of the fluorescent calcium binding Fura 2, or pH-sensitive carboxyfluorescein, BCECF, respectively. Both the auxin-induced shifts in the ion concentrations were specific to the physiologically active synthetic auxin, naphthalene-1-acetic acid (1-NAA), and not to the non-active naphthalene-2-acetic acid (2-NAA). Regardless of the age of the seedlings, the rise in [Ca(2+)](cyt) was prior to the acidification in all investigated cases. The maximal acidification coincided with the highest amplitude of [Ca(2+)](cyt) change, but not directly depended on the concentration of 1-NAA. Within aging of the seedlings the amplitude of auxin-induced [Ca(2+)](cyt) elevation decreased. The shift in auxin-induced acidification was almost equal at 3rd and 4th day, but largely dropped at 5th day of development. The acidification was related to changes in the plasma membrane H(+)-ATPase activity, detected as phosphate release. The decrement in amplitude of both the tested auxin-triggered reactions well coincided with the end of the physiological function of the coleoptile. Hence the primary auxin-induced increase in [Ca(2+)](cyt), which is supposed to be an important element of hormone signal perception and transduction, can be used as a test for elucidation of plant cell sensitivity to auxin. 相似文献
98.
Giordanetto F Karlsson O Lindberg J Larsson LO Linusson A Evertsson E Morgan DG Inghardt T 《Bioorganic & medicinal chemistry letters》2007,17(15):4232-4241
We herein report the optimization of cyclopentane- and cyclohexane-1,3-diamine derivatives as novel and potent MCH-R1 antagonists. Structural modifications of the 2-amino-quinoline and thiophene moieties found in the initial lead compound served to improve its metabolic stability profile and MCH-R1 affinity, and revealed unprecedented SAR when compared to other 2-amino-quinoline-containing MCH-R1 antagonists. 相似文献
99.
The complex evolutionary history of the Eurasian gastropod lineage Theodoxus reflects the evolution of marine basins following the breakup of the Tethys Sea. Today, this clade inhabits the lakes, rivers, streams, and estuaries of Europe, southwestern Asia, and North Africa. Here we present the first phylogenetic hypothesis for this clade. Based upon extensive geographic and taxonomic sampling, portions of the mitochondrial genes for cytochrome c oxidase subunit I and 16S rRNA were sequenced and analysed using maximum likelihood and maximum parsimony methods. Results from bootstrap analyses, Bayesian analysis, and sensitivity analyses lend support to six deep phylogenetic subdivisions within Theodoxus. These major clades are geographically associated with the major post-Tethyan marine basins. Estimates of divergence times using a penalized likelihood approach indicate that divergence of these major lineages occurred during the Miocene, simultaneous with the breakup of the Mediterranean and Paratethys Seas. The resulting major subclades later diversified during the Pliocene, primarily within geographic regions associated with the eastern and western Mediterranean Sea, the Pannonian Basin, and the Black Sea, thus producing the extant species assemblages. Finally, these phylogenetic results imply that much of the current taxonomy is flawed, therefore we offer recommendations for revising the classification of Theodoxus species based on phylogenetic systematics. 相似文献
100.
Robert Linder Eva R?nmark Jamshid Pourazar Annelie Behndig Anders Blomberg Anne Lindberg 《Respiratory research》2015,16(1)