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131.
Mike Friedrich Revaz Nozadze Qiang Gan Vladimir Ermolayev Gregory S. Harms 《Biochemical and biophysical research communications》2009,390(3):722-8
Single-molecule detection and tracking is important for observing biomolecule interactions in the microenvironment. Here we report selective plane illumination microscopy (SPIM) with single-molecule detection in living organisms, which enables fast imaging and single-molecule tracking and optical penetration beyond 300 μm. We detected single nanocrystals in Drosophila larvae and zebrafish embryo. We also report our first tracking of single quantum dots during zebrafish development, which displays a transition from flow to confined motion prior to the blastula stage. The new SPIM setup represents a new technique, which enables fast single-molecule imaging and tracking in living systems. 相似文献
132.
Three-phase partitioning of cells was carried out by mixing t-butanol and ammonium sulfate with aqueous suspension of cells. Permeabilized cells formed the interface between aqueous and alcohol layers. A preincubation step in which cells were exposed to just t-butanol was found to tune the selectivity of permeabilized cells of Thermus thermophilus,Saccharomyces cerevisiae, and Escherichia coli. Smaller proteins (green fluorescent protein and lipase with molecular weights of 29 and 34 kDa, respectively) were released with preincubation of 15 min, and penicillin G acylase (∼85 kDa) was released with preincubation of 30 min. The high-molecular-weight proteins (alcohol dehydrogenase from S. cerevisiae and T. thermophilus with molecular weights of 150 and 170 kDa, respectively) were retained even after preincubation of 60 min. The specific activities and electrophoretic analysis of some of the proteins obtained reflected their high purity. 相似文献
133.
Banana streak virus (BSV) is a plant dsDNA pararetrovirus (family Caulimoviridae, genus badnavirus). Although integration is not an essential step in the BSV replication cycle, the nuclear genome of banana (Musa sp.) contains BSV endogenous pararetrovirus sequences (BSV EPRVs). Some BSV EPRVs are infectious by reconstituting a functional
viral genome. Recent studies revealed a large molecular diversity of episomal BSV viruses (i.e., nonintegrated) while others
focused on BSV EPRV sequences only. In this study, the evolutionary history of badnavirus integration in banana was inferred from phylogenetic relationships between BSV and BSV EPRVs. The relative evolution rates
and selective pressures (dN/dS ratio) were also compared between endogenous and episomal viral sequences. At least 27 recent independent integration events
occurred after the divergence of three banana species, indicating that viral integration is a recent and frequent phenomenon.
Relaxation of selective pressure on badnaviral sequences that experienced neutral evolution after integration in the plant
genome was recorded. Additionally, a significant decrease (35%) in the EPRV evolution rate was observed compared to BSV, reflecting
the difference in the evolution rate between episomal dsDNA viruses and plant genome. The comparison of our results with the
evolution rate of the Musa genome and other reverse-transcribing viruses suggests that EPRVs play an active role in episomal BSV diversity and evolution. 相似文献
134.
Shang-Te Danny Hsu Caroline Behrens Lisa D. Cabrita Christopher M. Dobson 《Biomolecular NMR assignments》2009,3(1):67-72
We present here the backbone and side-chain NMR assignments of YFP Venus, a 238-residue protein that emits yellow fluorescence
in its native state. Venus is a variant of the green fluorescent protein (GFP), which has improved chromophore maturation
and brightness, and the photochemistry and photophysics of which are insensitive to experimental conditions, such as the pH
value and buffer content, making it a favourable biomarker. 相似文献
135.
Pivotal brain functions, such as neurotransmission, cognition, and memory, decline with advancing age and, especially, in neurodegenerative conditions associated with aging, such as Alzheimer's disease (AD). Yet, deterioration in structure and function of the nervous system during aging or in AD is not uniform throughout the brain. Selective neuronal vulnerability (SNV) is a general but sometimes overlooked characteristic of brain aging and AD. There is little known at the molecular level to account for the phenomenon of SNV. Functional genomic analyses, through unbiased whole genome expression studies, could lead to new insights into a complex process such as SNV. Genomic data generated using both human brain tissue and brains from animal models of aging and AD were analyzed in this review. Convergent trends that have emerged from these data sets were considered in identifying possible molecular and cellular pathways involved in SNV. It appears that during normal brain aging and in AD, neurons vulnerable to injury or cell death are characterized by significant decreases in the expression of genes related to mitochondrial metabolism and energy production. In AD, vulnerable neurons also exhibit down-regulation of genes related to synaptic neurotransmission and vesicular transport, cytoskeletal structure and function, and neurotrophic factor activity. A prominent category of genes that are up-regulated in AD are those related to inflammatory response and some components of calcium signaling. These genomic differences between sensitive and resistant neurons can now be used to explore the molecular underpinnings of previously suggested mechanisms of cell injury in aging and AD. 相似文献
136.
Parham Taslimi Sabiya Osmanova İlhami Gulçin Sabira Sardarova Vagif Farzaliyev Afsun Sujayev Ruya Kaya Fatma Koc Sukru Beydemir Saleh H. Alwasel Omer Irfan Kufrevioglu 《Journal of biochemical and molecular toxicology》2017,31(9)
Compounds containing nitrogen and sulfur atoms can be widely used in various fields, including industry, medicine, biotechnology, and chemical technology. Among them, amides of acids and heterocyclic compounds have an important place. These amides and thiazolidine‐4‐ones showed good inhibitory action against butyrylcholinesterase (BChE), acetylcholinesterase (AChE), and human carbonic anhydrase isoforms. AChE exists at high concentrations in the brain and red blood cells. BChE is an important enzyme that is plentiful in the liver, and it is released into the blood in a soluble form. They were demonstrated to have effective inhibition profiles with Ki values of 23.76–102.75 nM against hCA I, 58.92–136.64 nM against hCA II, 1.40–12.86 nM against AChE, and 9.82–52.77 nM against BChE. On the other hand, acetazolamide showed Ki value of 482.63 ± 56.20 nM against hCA I, and 1019.60 ± 163.70 nM against hCA II. Additionally, Tacrine inhibited AChE and BChE, showing Ki values of 397.03 ± 31.66 and 210.21 ± 15.98 nM, respectively. 相似文献
137.
İlhami Gulçin Malahat Abbasova Parham Taslimi Zübeyir Huyut Leyla Safarova Afsun Sujayev 《Journal of enzyme inhibition and medicinal chemistry》2017,32(1):1174-1182
Compounds containing nitrogen and sulfur atoms can be widely used in various fields such as industry, medicine, biotechnology and chemical technology. Therefore, the reactions of aminomethylation and alkoxymethylation of mercaptobenzothiazole, mercaptobenzoxazole and 2-aminothiazole were developed. Additionally, the alkoxymethyl derivatives of mercaptobenzoxazole and 2-aminothiazole were synthesized by a reaction with hemiformals, which are prepared by the reaction of alcohols and formaldehyde. In this study, the inhibitory effects of these molecules were investigated against acetylcholinesterase (AChE), butyrylcholinesterase (BChE) enzymes and carbonic anhydrase I, and II isoenzymes (hCA I and II). Both hCA isoenzymes were significantly inhibited by the recently synthesized molecules, with Ki values in the range of 58–157?nM for hCA I, and 81–215?nM for hCA II. Additionally, the Ki parameters of these molecules for BChE and AChE were calculated in the ranges 23–88 and 18–78?nM, respectively. 相似文献
138.
The objective of the present study was to develop a new selective, differential and cost-effective medium (Kim and Rhee — KR-medium) for the isolation of Cronobacter spp. In this new medium, which contained salicin as a differential agent, Cronobacter spp. generated typical colonies with characteristic violet-colored centers surrounded by a transparent to opalescent border, and the growth of other microorganisms (40 strains) was inhibited or produced visually distinguishable colonies. Using healthy and heat- and desiccation-injured cells, the quantity of nutrients was adjusted to determine the optimal recovery rate, selectivity, differentiation and cost-effectiveness. Peptone and salicin concentrations were established as 10 and 8 g/L, respectively. The KR medium was then validated using salicin fermenting organisms, including Cronobacter spp. (52 strains), Enterobacter cloacae (50 strains) and Klebsiella pneumonia (10 strains) isolated from clinical and food specimens. All strains of Cronobacter spp. produced typical colonies and other salicin fermenting organisms were easily distinguishable from Cronobacter spp. with the exception of 2 E. cloacae strains. The verification of KR medium was carried out in powdered infant formula artificially inoculated with healthy, heat-injured, and desiccation-injured Cronobacter spp. and the expected typical colonies were appeared. The KR medium had a high specificity (98%) and sensitivity (100%), with no false-negative results. Moreover, we show that the cost of the KR medium is much lower than that of other selective and differential media. The use of the KR medium for the selective isolation of Cronobacter spp. in laboratories and food industry settings may therefore lessen the financial burden of Cronobacter spp. detection. 相似文献
139.
Thomas Trancart Patrick Lambert Françoise Daverat Julien Coustillas 《Journal of experimental marine biology and ecology》2011,399(2):120-129
Swimming activity of thinlip mullet Liza ramada in response to water current reversal was investigated experimentally. A total of 130 young of the year thinlip mullet ranging in size from 22 to 36 mm were entered in trials with four different conditions over three weeks. The fish were subjected to current reversal (6.2/6.2 h) and a Light-Dark cycle (12/12 h). Swimming direction (with or against the current) was video-recorded throughout the experiments. The mullet showed an effective synchronisation of their swimming activity to water current reversal and Light-Dark cycle. This synchronisation could demonstrate the existence of a diurnal selective tidal-stream transport in the natural environment as observed in the two other European catadromous species. 相似文献
140.
《Bioorganic & medicinal chemistry letters》2014,24(18):4504-4510
To develop potent and selective nNOS inhibitors, a new series of double-headed molecules with chiral linkers that derive from natural amino acid derivatives have been designed and synthesized. The new structures integrate a thiophenecarboximidamide head with two types of chiral linkers, presenting easy synthesis and good inhibitory properties. Inhibitor (S)-9b exhibits a potency of 14.7 nM against nNOS and is 1134 and 322-fold more selective for nNOS over eNOS and iNOS, respectively. Crystal structures show that the additional binding between the aminomethyl moiety of 9b and propionate A on the heme and tetrahydrobiopterin (H4B) in nNOS, but not eNOS, contributes to its high selectivity. This work demonstrates the advantage of integrating known structures into structure optimization, and it should be possible to more readily develop compounds that incorporate bioavailability with these advanced features. Moreover, this integrative strategy is a general approach in new drug discovery. 相似文献