共查询到20条相似文献,搜索用时 31 毫秒
1.
Yu. V. Malyukin I. A. Borovoi N. S. Kavok A. V. Gerashchenko N. L. Pogrebnyak S. L. Efimova A. N. Lebedenko 《Biophysics》2007,52(4):406-411
A study was made of the inclusion of fluorescent probe H-510 based on 3,3′-dialkyloxacarbocyanine bromide (where alkyl is ethyl, nonyl, or octadecyl) into cells of different types. Alkyl chain length (C2, C9, or C18) was found to largely determine the accumulation dynamics and mechanism. Similar spectral characteristics for all probe types in bone marrow cells were found by microfluorimetry, suggesting insertion of dye molecules irrespective of their lipophilicity into micelle-like structures formed probably by cell phospholipids. Spectroscopy data indicate interaction of 3,3′-diethyloxacarbocyanine bromide (H-510/C2) and 3,3-dinonyloxacarbocyanine bromide (H-510/C9) dyes in hepatocytes with a less polar microenvironment (nonpolar and low-polar lipids that constitute a significant part of the total content of cell lipids). The fluoresccence maximum of long-chain dye H-510/C18 in hepatocytes is shifted to the short-wavelength region and strictly coincides with the fluorescence maximum of the probe in an albumin solution. It is not excluded that inclusion of the probe into cells occurs via endocytosis upon its binding to surface proteins. 相似文献
2.
Maliukin IuV Borovoĭ IA Kavok NS Gerashchenko AV Pogrebniak NL Efimova SL Lebedenko AN 《Biofizika》2007,52(4):667-673
The incorporation of the fluorescent probe 3,3-dialkyloxacarbocyanine bromide H-510 (where alkyl is ethyl- (C2), nonyl- (C9), or octadecyl (C18) groups) into cells of different kind has been explored. It has been revealed that the length of alkyl chains significantly influences the dynamics and mechanisms of accumulation of the probe by the cells. It has been found by microfluorimetry that all probe species have similar spectral characteristics in bone marrow cells, indicating that all probes, independently on their lipophilic properties, are incorporated into micelle-like structures formed probably by cell phospholipids. Spectroscopy experiments have shown that, in hepatocytes, the fluorescent probes 3,3-diethyloxacarbocyanine bromide (H-510/C2) and 3,3-dinonyloxacarbocyanine bromide (H-510/C9) are mainly accumulated in weakly polar media (nonpolar and weakly polar lipids of these cells). The luminescence maximum of the H-510/C18 probe in hepatocytes is blue-shifted and coincides with that in an albumin solution. We suppose that the incorporation of the probe into cells occurs by endocytosis when the probe binds to surface proteins. 相似文献
3.
Yu. V. Malyukin N. S. Kavok I. A. Borovoi A. M. Stepanenko M. Yu. Malyukina P. A. Petrukhin 《Biophysics》2011,56(3):452-456
The resting membrane potential of isolated hepatocytes from 2- and 20-month-old rats and its changes upon activation of cells
by adrenaline have been studied by the method of quantitative microfluorimetry using diethyl derivatives of polymethine probes
(H-510 and D-307). The potential was estimated by the Nernst equation adapted to lipophilic cationic probes. It was shown
using both probes that the transmembrane potential of hepatocytes decreases with age. The microfluorimetry data were confirmed
by the results of spectrofluorimetric measurements in a cell suspension. Changes in fluorescence occurring in adrenaline-activated
single cells and suspensions were unidirectional, the effect of the hormone on the cells of old animals being less pronounced.
The results indicate that the potential of the plasma membrane of individual hepatocytes can be adequately estimated by microfluorimetry,
which can be used in metabolic and toxicologic investigations. 相似文献
4.
Three fluorescent probes, tetramethyl rhodamine ethyl ester (TMRE), 3,3′-dipropylthiacarbocyanine iodide (diS-C3(3)) and 3,3′-dipropyloxacarbocyanine iodide (diO-C3(3)), were tested for their suitability as fluorescent indicators of membrane potential inSaccharomyces cerevisiœ in studies performed by flow cytometry. For all these dyes the intensity of fluorescence of stained cells increased with
probe concentration in the range of 60–3000 nmol/L. The optimum staining period was 15–20 min for diS-C3(3). Depolarization of cells by increased extracellular potassium level and by valinomycin elicited with all probes a drop
in fluorescence intensity. In some yeast batches this depolarization was accompanied by a separation of subpopulations with
different fluorescence properties. 相似文献
5.
Zhang Z Qun J Cao C Wang J Li W Wu Y Du L Zhao P Gong K 《Molecular biology reports》2012,39(4):4445-4454
Circulating endothelial progenitor cells (EPCs) have a critical role in endothelial maintenance and repair. Apolipoprotein
A-I mimetic peptide D-4F has been shown to posses anti-atherogenic properties via sequestration of oxidized phospholipids,
induction of remodeling of high density lipoprotein and promotion of cholesterol efflux from macrophage-derived foam cells.
In this study, we test the effects of D-4F on EPC biology. EPCs were isolated from the peripheral venous blood of healthy
male volunteers and characterized by 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine-labeled acetylated LDL uptake
and ulex europaeus agglutinin binding and flow cytometry. Cell proliferation, migration, adhesion, nitric oxide production
and endothelial nitric oxide synthase (eNOS) expression in the absence and presence of D-4F or simvastatin (as a positive
control), were assayed. We demonstrated that D-4F significantly enhanced EPC proliferation, migration and adhesion in a dose-dependent
manner compared with vehicle. However, all of the favorable effects of D-4F on EPCs were dramatically attenuated by preincubation
with NOS inhibitor L-NAME. Further, D-4F also increased nitric oxide production in culture supernatant and the levels of eNOS
expression and phosphorylation. The stimulatory effects of D-4F (10 μg/ml) on EPC biology were comparable to 0.5 μM simvastatin.
These results suggest that eNOS/NO pathway mediates the functional modulation of EPC biology in response to D-4F treatment
and support the notion that the beneficial role of D-4F on EPCs may be one of the important components of its anti-atherogenic
potential. 相似文献
6.
The role of 3′,5′-cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), protein kinase C (PKC) and phosphatases
in the regulation of the taurine influx via the β-system in Ehrlich ascites tumor cells has been investigated. The taurine
uptake by the β-system in Ehrlich cells is inhibited when PKC is activated by phorbol 12-myristate 13-acetate (PMA) and when
protein phosphatases are inhibited by calyculin A (CLA). On the other hand, taurine uptake by the β-system is stimulated by
an increased level of cAMP or following addition of N6,2′-O-dibutyryl-3′,5′-cyclic adenosine monophosphate (dbcAMP). The effect of dbcAMP is partially blocked by addition of the
protein kinase inhibitor H-89, and suppressed in the presence of CLA. It is proposed that the β-system in the Ehrlich cells
exists in three states of activity: State I, where a PKC phosphorylation site on the transporter or on a regulator is phosphorylated and transport activity is low. State II, where the PKC phosphorylation site is dephosphorylated and transport activity is normal. State III, representing a state with high transport activity, induced by an elevated cellular cAMP level. Apparently, cAMP preferentially
stimulates taurine transport when the β-system is in State II.
Received: 8 September/Revised: 9 November 1995 相似文献
7.
Reduction of nitro-substituted compounds, 1,4-benzodiazepine-2-ones, dibenzo[b,f]-1,4-diaz-epines, quinolones, and quinoxalinones,
byEscherichia coli cells was studied. Physicochemical methods demonstrated the formation of corresponding amines. 4-(p-Nitrophenyl)-1H-6-R-quinolones-2 were nor reduced byEscherichia coli cells. Regiospecific reduction of 2,4-dinitro-5H-l l-(p-R-phenyl)-dibenzo[b,f]-1,4-diazepines and 4-(2′-R-3′,5′-dinitro)-benzoyl-3,4-dihydroquinoxalinones-2 was shown to result
in the formation of 2-nitro-4-amino-5H-11-(p-R-phenyl)-dibenzo[b,f]-1,4-diazepines and 4-(2′-R-3′-nitro-5′-amino)-benzoyl-3,4-dihydroquinoxalinones-2,
respectively. Methods for microbiological reduction of nitro compounds and immobilization ofEscherichia coli cells into carrageenan and its modified forms were elaborated. 相似文献
8.
Matteucci E Ghimenti M Consani C Masoni MC Giampietro O 《Cell biochemistry and biophysics》2011,59(2):121-126
Proper cellular function requires the maintenance of mitochondrial membrane potential (MMP) sustained by the electron transport
chain. Mitochondrial dysfunction is believed to play a role in the development of diabetes and diabetic complications possibly
because of the active generation of free radicals. Since MMP can be investigated in clinical settings using fluorescent probes
and living whole blood cells, mitochondrial membrane alterations have been observed in some chronic disorders. We have used
the mitochondrial indicator 5,5′,6,6′-tetra chloro-1,1′,3,3′-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) in conjunction
with flow cytometry to measure the MMP in peripheral blood granulocytes from type 1 diabetes (T1D) families. The intracellular
ROS levels and the respiratory burst activity were also measured. Leukocyte MMP was elevated in 20 T1D patients and their
20 non-diabetic siblings compared with 25 healthy subjects without family history of T1D. Fasting plasma glucose was the only
correlate of MMP. If confirmed by further observations, the functional implications of mitochondrial hyperpolarisation (probably
different among different cells) will require extensive investigation. 相似文献
9.
Summary. Ratiometric fluorescent dyes are often used to monitor free ion concentrations in vivo, especially in cells that are recalcitrant
to transformation with genetically encoded fluorescent markers. Although intracellular dye distributions are often found to
be cytosolic, dye localisation has often not been examined in detail. We began exploring the use of BCECF (2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein)
to monitor pH in the giant alga Chara australis and discovered that younger leaf cells could be loaded using the acetoxymethyl ester of BCECF. However, we were puzzled to
find in microphotometric measurements that the fluorescence ratio appeared insensitive to manipulations affecting cytosolic
pH. Confocal imaging of C. australis cells loaded with BCECF showed an accumulation of the dye in two locations: (1) on the outside of the chloroplasts in irregularly
shaped stationary bodies; (2) within 1–1.5 μm structures that moved rapidly with the pericellular cytoplasmic streaming. Together
with the streaming cytoplasm, these organelles were rendered stationary with 50 μM cytochalasin D. Rhodamine 123, a mitochondrionspecific
dye, highlighted organelles outside of the chloroplasts, similar to those shown by BCECF in location 1. We conclude that in
the cytoplasmic compartment, BCECF was sequestered within cytoplasmic mitochondria in immature and fast-growing cells and
within the cortical mitochondrial system in older and slowly growing cells. Thus, BCECF-AM is unsuitable for reporting changes
in cytosolic pH in C. australis but might be employed in future to study pH changes in the mitochondria.
Correspondence: M. J. Beilby, Biophysics, School of Physics, University of New South Wales, Sydney 2052, Australia. 相似文献
10.
Synergistic multivalent interactions can amplify desired chemical or biological molecular recognitions. We report a new class of multicarboxylate-containing carbocyanine dye constructs for use as optical scaffolds that not only serve as fluorescent antennas but also participate in structural assembly of the multivalent molecular construct. Three generations of carboxylate-terminating multivalent near-infrared carbocyanine probes from a dicarboxylic acid precursor dye (cypate) were prepared via its imino diacetic acid derivatives. Conjugation of the probes with D-(+)-glucosamine afforded dendritic arrays of the carbohydrates on an inner NIR chromophore core. All the multicarboxylate probes and their glucosamine conjugates have similar NIR spectral properties because conjugation occurred at distal positions to the inner chromophore core, thereby providing consistent and predictable spectral properties for their biological applications. Although light-induced photodamage equally affected the precursor dye, multicarboxylate probes, and their glucosamine derivatives, we observed that octacarboxylcypate (multivalent probe) was remarkably stable in different mediums at physiologically relevant temperatures relative to cypate, especially in basic mediums. Biodistribution studies in tumor-bearing nude mice show that all the glucosamine conjugates localized in the tumor but cypate was almost exclusively retained in the liver at 24 h postinjection. The tumor uptake does not correlate with the number of glucosamine tether on the multicarboxylate probe. Overall, the triglucosamine derivative appears to offer the best balance between high tumor uptake and low retention in nontarget tissues. These results suggest that multivalent molecular beacons are useful for assessing the beneficial effects of multivalency and for optimizing the biological and chemical properties of tissue-specific molecular probes. 相似文献
11.
12.
Interferons (IFNs) induce a 2′,5′-oligoadenylate (2-5A)-dependent ribonuclease L (RNase L) following virus-infection of mammalian
cells. RNase L degrades both viral and cellular RNAs and restricts virus-proliferation. We have studied organization of RNase
L gene in genomic DNA from the mouse liver by Southern blot analysis. Several BamHI, BglII, EcoRI, HincII, HindIII, NcoI, PstI, SacI, and XbaI restriction fragments hybridized to 32P-labeled mouse RNase L cDNA and the 5′-proximal exon probes. Mouse RNase L gene exists as a single copy (>16 kb DNA) gene.
A 5 kb HindIII and a 2.5 kb EcoRI DNA were detected as 5′-upstream DNA of the gene which may contain mouse RNase L promoter. Our results will help studying
mouse RNase L gene promoter in further details. 相似文献
13.
Hong Lu Jiti Zhou Jing Wang Guangfei Liu Lihong Zhao 《World journal of microbiology & biotechnology》2008,24(7):1147-1152
Sphingomonas xenophaga QYY from sludge samples could effectively decolorize 1-aminoanthraquinone-2-sulfonic acid (ASA-2), one kind of anthraquinone
dye intermediate, under aerobic conditions. More than 98% of ASA-2 could be removed within 120 h at the dye concentration
from 200 mg l−1 to 1,000 mg l−1 due to oxidative degradation. The strain converted ASA-2 to 2-(2′-hydroxy-3′-amino-4′-sulfo-benzoyl)-benzoic acid, 2-(2′-amino-3′-sulfo-6′-hydroxy-benzoyl)-benzoic
acid, o-phthalic acid and 2-amino-3-hydroxy-benzenesulfonic acid, which were identified using HPLC-MS and NMR. A possible
initial decolorization pathway was proposed according to these metabolites. The decolorization of ASA-2 by cells in the basal
salt medium was induced by ASA-2, and was due to soluble cytosolic enzymes. Combined initial decolorization pathway and the
analysis of decolorization enzyme(s), the major enzyme responsible for ASA-2 decolorization was a NADH-dependent oxygenase. 相似文献
14.
Antonini I Polucci P Magnano A Cacciamani D Konieczny MT Paradziej-Łukowicz J Martelli S 《Bioorganic & medicinal chemistry》2003,11(3):399-405
A series of potential DNA-binding antitumor agents, 3-[omega-(alkylamino)alkyl]-6-nitro-thiadiazino[3,4,5-kl]acridines 12 and 1,3-di[omega-(alkylamino)alkyl]-6-nitro-thiadiazino[3,4,5-kl]acridines 13, has been prepared by cyclization with SOCl(2) of 1-[[omega-(alkylamino)alkyl]amino]-9-imino-4-nitro-9,10-dihydroacridines 16 or 1-[[omega-(alkylamino)alkyl]amino]-9-[omega-(alkylamino)alkyl]imino-4-nitro-9,10-dihydroacridines 17, respectively. The non-covalent DNA-binding properties of 12, 13 have been examined using a fluorometric technique. In vitro cytotoxic potencies of these derivatives toward six tumor cell lines, including human colon adenocarcinoma (HT29) and human ovarian carcinoma (A2780 sensitive, A2780cisR cisplatin-resistant, CH1, CH1cisR cisplatin-resistant, and SKOV-3) cells, are described and compared to that of reference drugs. In vivo antitumor activity of some selected derivatives, endowed with relevant cytotoxic activity against murine leukemia P388 are reported. The 3-[2-(dimethylamino)ethyl]-6-nitro-2,7-dihydro-3H-2 lambda(4)-thiadiazino[3,4,5-kl]acridin-2-one (12d) has been identified as a new lead in the development of anticancer tetracyclic acridine derivatives. 相似文献
15.
Sialyl oligosaccharides have long been considered to be the sole receptors for influenza virus. However, according to [1]
some viruses are able to grow in sialic-free MDCK cells. Here we attempted to reveal a possible second, non-sialic receptor,
hypothesizing the involvement of additional carbohydrate lectin recognition in influenza virus reception process, first of
all in situations when a lectin of the host cell could recognize the viral carbohydrate ligand. We tested the presence of
galactose- and sialic acid-binding lectins, as well as mannoside- and sulfo-N-acetyllactosamine-recognizing properties of MDCK and Vero cells using polyacrylamide neoglycoconjugates and antibodies. MDCK
cells bind galactoside probes stronger than Vero cells, whereas Vero cells bind preferentially sialoside, mannoside and various
sulfo-oligosaccharide probes. The probing of viruses with the neoglycoconjugates revealed specific 6′-HSO 3 LacNAc (but not other sulfated oligosaccharides) binding property of A and B human strains. Affinity of 6′-HSO 3 LacNAc probe was comparable with affinity of 6′-SiaLac probe but the binding was not inhibited by the sialooligosaccharide. 相似文献
16.
H. Ardag Akdogan A. Demircali C. Aydemir N. Pazarlioglu F. Karci 《Applied Biochemistry and Microbiology》2011,47(5):538-542
In this study; sub-tropical white rot fungi, Trametes versicolor was investigated for its ability to degrade 4-(3′-methyl-4′-(4″-nitrophenyl)azo-1′H-pyrazol-5′-ylazo)-3-methyl-1H-pyrazol-5-on
in the mediums containing glucose and different concentrations of degrade dye in batch systems. This dye was synthetized at
Pamukkale Universtiy of Organic Chemistry research laboratory. Samples were collected on 10 days, and was detected by Shimadzu
UV-1600A spectrophotometry. Decolorization study showed that this disazo dye was removed by more than 70% in 10 days. Laccase
enzyme activity was detected in samples and then last sample was analyzed by GC-MS. Metabolites weren’t showed in GC-MS result.
It was concluded that T. versicolor could achieve the biodegradation of this new disazo dye. 相似文献
17.
Takayasu Motoyama Yutaka Okumoto Takatoshi Tanisaka Shigeru Utsumi Nobuyuki Maruyama 《Transgenic research》2010,19(5):819-827
A transgenic rice that produces both the α′ and β subunits of β-conglycinin has been developed through the crossing of two
types of transgenic rice. Although the accumulation level of the α′ subunit in the α′β-transgenic rice was slightly lower
than that in the transgenic rice producing only the α′ subunit, the accumulation level of the β subunit in the α′β-transgenic
rice was about 60% higher than that in the transgenic rice producing only the β subunit. Results from sequential extraction
and gel-filtration experiments indicated that part of the β subunit formed heterotrimers with the α′ subunit in a similar
manner as in soybean seeds and that the heterotrimers interacted with glutelin via cysteine residues. These results imply
that the accumulation level of the β subunit in the α′β-transgenic rice increases by an indirect interaction with glutelin.
Immunoelectron microscopy revealed that the α′ and β subunits are localized in a low electron-dense region of protein body-II
(PB-II) and that α′ homotrimers in the α′β-transgenic rice seeds seem to accumulate outside of this low electron-dense region. 相似文献
18.
M. F. Kasakin T. V. Abramova V. N. Silnikov 《Russian Journal of Bioorganic Chemistry》2011,37(6):752-757
A simple and efficient method has been developed for the preparation of 2′-aminomethylmorpholino-4′-carboxymethyl nucleoside
analogues and their 2′-N-Boc-modified derivatives as synthons for obtaining oligomers by peptide synthesis methods. 相似文献
19.
Ciesielska E Studzian K Wasowska M Oszczapowicz I Szmigiero L 《Cell biology and toxicology》2005,21(3-4):139-147
Daunorubicin (DRB) and its two analogues containing a trisubstituted amidino group at the C-3′ position of the daunosamine
moiety have been compared regarding their cytotoxic activity, cellular uptake, subcellular localization and DNA damaging properties.
An analogue containing in the amidino group a morpholine moiety (DRBM) as well as an analogue with a hexamethyleneimine moiety
(DRBH), tested against cultured L1210 cells, exhibited lower cytotoxicity then DRB. The decrease of cytotoxic activity was
not related to cellular uptake and subcellular localization of drugs. Although all tested drugs were active in the induction
of DNA breaks and DNA–protein crosslinks, they differed in the mechanism of induction of DNA lesions. DRB produced DNA breaks
mediated solely by topoisomerase II, whereas DRBM and DRBH induced two types of DNA breaks by two separate processes. The
first is related to the inhibition of topoisomerase II and the second presumably reflects a covalent binding of drug metabolites
to DNA. It is hypothesized that the replacement of the primary amino group (–NH2) at the C-3′ position of the daunosamine moiety by a trisubstituted amidino group (–N=CH–NRR) may be a route to the synthesis
of anthracycline derivatives with enhanced ability to form covalent adducts to DNA. 相似文献
20.
N.-J. L. Liu Deborah E. Isaksen C. M. Smith D. A. Weisblat 《Development genes and evolution》1998,208(3):117-127
At the four-cell stage, embryos of glossiphoniid leeches comprise identified blastomeres A, B, C and D. Subsequent cleavages
of the A, B and C quadrants yield three large, yolk-rich endodermal precursor cells, macromeres A′′′, B′′′ and C′′′. Eventually,
these cells generate the epithelial lining of the gut via cellularization of a multinucleate syncytium. Meanwhile, cleavage
in the D quadrant generates ten teloblasts that give rise to segmental mesoderm and ectoderm via stem cell divisions. Here
we show that, during cleavage, macromeres A′′′, B′′′ and C′′′ shift clockwise relative to the D quadrant, while C′′′ comes
to envelop the nascent teloblasts. During gastrulation, derivatives of the teloblasts undergo epibolic movements over the
surface of the A′′′, B′′′ and C′′′ macromeres to form the germinal plate, from which segmental tissues arise. We find that
the three macromeres fuse in a stepwise manner to initiate formation of the multinucleate syncytium; cell C′′′ fuses about
25 h after the fusion of A′′′ and B′′′, and the teloblasts fuse with the macromere-derived syncytium later still. When macromeres
are biochemically arrested by microinjecting them with the A chain of ricin, a further difference among the macromeres is
revealed. Biochemical arrest of A′′′ or B′′′ slightly retards the rate of germinal plate formation, but arrest of C′′′ frequently
accelerates this process.
Received: 14 October 1997 / Accepted: 4 February 1998 相似文献