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Chemico-biological Interactions Aug 2019Structure-guided design of novel pharmacologically active molecules relies at least in part on functionally relevant accuracy of macromolecular structures for template...
Structure-guided design of novel pharmacologically active molecules relies at least in part on functionally relevant accuracy of macromolecular structures for template based drug design. Currently, about 95% of all macromolecular X-ray structures available in the PDB (Protein Data Bank) were obtained from diffraction experiments at low, cryogenic temperatures. However, it is known that functionally relevant conformations of both macromolecules and pharmacological ligands can differ at higher, physiological temperatures. We describe in this article development and properties of new human acetylcholinesterase (AChE) crystals of space group P3 and a new unit cell, amenable for room-temperature X-ray diffraction studies. We co-crystallized hAChE in P3 unit cell with the reversible inhibitor 9-aminoacridine that binds at the base of the active center gorge in addition to inhibitors that span the full length of the gorge, donepezil (Aricept, E2020) and AChE specific inhibitor BW284c51. Their new low temperature P3 space group structures appear similar to those previously obtained in the different P321 unit cell. Successful solution of the new room temperature 3.2 Å resolution structure of BW284c51*hAChE complex from large P3 crystals enables us to proceed with studying room temperature structures of lower affinity complexes, such as oxime reactivators bound to hAChE, where temperature-related conformational diversity could be expected in both oxime and hAChE, which could lead to better informed structure-based design under conditions approaching physiological temperature.
Topics: Acetylcholinesterase; Aminacrine; Binding Sites; Cholinesterase Inhibitors; Crystallography, X-Ray; Dimerization; Humans; Molecular Dynamics Simulation; Protein Structure, Quaternary; Protein Structure, Tertiary; Recombinant Proteins; Temperature
PubMed: 31176713
DOI: 10.1016/j.cbi.2019.06.011 -
Journal of Lipid Research Jun 2010Recently, we used the favorable properties of 9-aminoacridine (9-AA) as matrix for the quantitative analysis of acidic metabolites and glycerophospholipids from extracts...
Recently, we used the favorable properties of 9-aminoacridine (9-AA) as matrix for the quantitative analysis of acidic metabolites and glycerophospholipids from extracts of biological materials [Sun, G., Yang, K., Zhao, Z., Guan, S., Han, X., and Gross, R.W. (2007) A shotgun metabolomics approach for rapid analysis of negatively-charged water-soluble cellular metabolites from mouse heart tissue. Anal. Chem. 79: 6629-6640; Sun, G., Yang, K., Zhao, Z., Guan, S., Han, X., and Gross, R.W. (2008) Matrix-assisted laser desorption/ionization-time of flight mass spectrometric analysis of cellular glycerophospholipids enabled by multiplexed solvent dependent analyte-matrix interactions. Anal. Chem. 80: 7576-7585.] by MALDI-MS. Herein, we extend this discovery and identified the selective desorption/ionization of sulfatides over other examined anionic lipids present in lipid extracts of biological samples by MALDI-MS using 9-AA as matrix. Through this approach, a high throughput method for the quantitative analysis of low to very low abundance sulfatide molecular species directly from crude lipid extracts has been developed. This method possessed a linear dynamic range of over 1,000-fold, a detection limit at the high attomole level, and a reproducibility of approximately 10% deviation. Many potential factors that might affect the quantitation of sulfatide species employing the method were examined and their effects were found to be negligible within experimental error. Collectively, these results demonstrate a powerful high throughput method for the measurement of sulfatides directly from extracts of biological samples, facilitating the study of sulfatide metabolism, trafficking, and homeostasis in health and disease.
Topics: Aminacrine; Animals; Cattle; Linear Models; Male; Mice; Phospholipids; Reference Standards; Reproducibility of Results; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Sulfoglycosphingolipids
PubMed: 20124011
DOI: 10.1194/jlr.D004077 -
Molecular and Cellular Biochemistry Oct 2019A series of nine tetrahydroacridine derivatives with iodobenzoic moiety were synthesized and evaluated for their cytotoxic activity against cancer cell lines-A549 (human...
Novel tetrahydroacridine derivatives with iodobenzoic moieties induce G0/G1 cell cycle arrest and apoptosis in A549 non-small lung cancer and HT-29 colorectal cancer cells.
A series of nine tetrahydroacridine derivatives with iodobenzoic moiety were synthesized and evaluated for their cytotoxic activity against cancer cell lines-A549 (human lung adenocarcinoma), HT-29 (human colorectal adenocarcinoma) and somatic cell line-EA.hy926 (human umbilical vein cell line). All compounds displayed high cytotoxicity activity against A549 (IC 59.12-14.87 µM) and HT-29 (IC 17.32-5.90 µM) cell lines, higher than control agents-etoposide and 5-fluorouracil. Structure-activity relationship showed that the position of iodine in the substituent in the para position and longer linker most strongly enhanced the cytotoxic effect. Among derivatives, 1i turned out to be the most cytotoxic and displayed IC values of 14.87 µM against A549 and 5.90 µM against HT-29 cell lines. In hyaluronidase inhibition assay, all compounds presented anti-inflammatory activity, however, slightly lower than reference compound. ADMET prediction showed that almost all compounds had good pharmacokinetic profiles. 1b, 1c and 1f compounds turned out to act against chemoresistance in cisplatin-resistant 253J B-V cells. Compounds intercalated into DNA and inhibited cell cycle in G0/G1 phase-the strongest inhibition was observed for 1i in A549 and 1c in HT-29. Among compounds, the highest apoptotic effect in both cell lines was observed after treatment with 1i. Compounds caused DNA damage and H2AX phosphorylation, which was detected in A549 and HT-29 cells. All research confirmed anticancer properties of novel tetrahydroacridine derivatives and explained a few pathways of their mechanism of cytotoxic action.
Topics: A549 Cells; Aminacrine; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Survival; Cisplatin; Colorectal Neoplasms; Cytoprotection; DNA; Drug Resistance, Neoplasm; G1 Phase Cell Cycle Checkpoints; HT29 Cells; Histones; Humans; Hyaluronoglucosaminidase; Inhibitory Concentration 50; Iodobenzoates; Lung Neoplasms; Mutagens; Oxidative Stress; Poly(ADP-ribose) Polymerases; Tumor Stem Cell Assay
PubMed: 31313023
DOI: 10.1007/s11010-019-03576-x -
Methods in Molecular Biology (Clifton,... 2013Capillary electrophoresis is a common technique used for glycosaminoglycan-derived disaccharide analysis because of its high resolving power, high separation efficiency,...
Capillary electrophoresis is a common technique used for glycosaminoglycan-derived disaccharide analysis because of its high resolving power, high separation efficiency, high sensitivity, short analysis time, and straightforward operation. CE coupled to laser-induced fluorescence (LIF) detection shows an approximately 100 times higher sensitivity than traditional UV detection at 232 nm. 2-Aminoacridone (AMAC) is a widely used fluorophore for labeling unsaturated disaccharides by deductive amination, which is one of the most important method of derivatization of disaccharides for CE-LIF detection. Outlined in this chapter is a protocol of analyzing glycosaminoglycan-derived disaccharides by CE-LIF with AMAC derivatization.
Topics: Aminacrine; Calibration; Carbohydrate Conformation; Carbohydrate Sequence; Disaccharides; Electrophoresis, Capillary; Glycosaminoglycans; Reference Standards
PubMed: 23386338
DOI: 10.1007/978-1-62703-296-4_7 -
The Biochemical Journal Dec 1981A lysyl-lysine bifunctional derivative of 9-aminoacridine has been synthesized and its DNA-binding capacity established by electron-paramagnetic-resonance study. For...
A lysyl-lysine bifunctional derivative of 9-aminoacridine has been synthesized and its DNA-binding capacity established by electron-paramagnetic-resonance study. For this purpose the binding parameters of a spin-labelled aminoacridine probe were estimated and the affinities of the lysylacridinyl-lysyldiamino-octane dimer and of 9-amino-acridine could be evaluated by competitive assays. The competition study provided quantitative results concerning the dissociation constant (KD) of the dimer. The obtained value was closely similar to the KD of 9-aminoacridine determined by the same method and to the KD previously reported for the anti-tumour and antibiotic bifunctional intercalator quinomycins.
Topics: Aminacrine; Binding Sites; Binding, Competitive; DNA; Electron Spin Resonance Spectroscopy; Intercalating Agents
PubMed: 6280671
DOI: 10.1042/bj1990479 -
The Journal of Biological Chemistry Jul 1989Mg-ATP dependent electrogenic proton transport, monitored with fluorescent acridine orange, 9-aminoacridine, and oxonol V, was investigated in a fraction enriched with... (Comparative Study)
Comparative Study
Mg-ATP dependent electrogenic proton transport, monitored with fluorescent acridine orange, 9-aminoacridine, and oxonol V, was investigated in a fraction enriched with potassium transporting goblet cell apical membranes of Manduca sexta larval midgut. Proton transport and the ATPase activity from the goblet cell apical membrane exhibited similar substrate specificity and inhibitor sensitivity. ATP and GTP were far better substrates than UTP, CTP, ADP, and AMP. Azide and vanadate did not inhibit proton transport, whereas 100 microM N,N'-dicyclohexylcarbodiimide and 30 microM N-ethylmaleimide were inhibitors. The pH gradient generated by ATP and limiting its hydrolysis was 2-3 pH units. Unlike the ATPase activity, proton transport was not stimulated by KCl. In the presence of 20 mM KCl, a proton gradient could not be developed or was dissipated. Monovalent cations counteracted the proton gradient in an order of efficacy like that for stimulation of the membrane-bound ATPase activity: K+ = Rb+ much greater than Li+ greater than Na+ greater than choline (chloride salts). Like proton transport, the generation of an ATP dependent and azide- and vanadate-insensitive membrane potential (vesicle interior positive) was prevented largely by 100 microM N,N'-dicyclohexylcarbodiimide and 30 microM N-ethylmaleimide. Unlike proton transport, the membrane potential was not affected by 20 mM KCl. In the presence of 150 mM choline chloride, the generation of a membrane potential was suppressed, whereas the pH gradient increased 40%, indicating an anion conductance in the vesicle membrane. Altogether, the results led to the following new hypothesis of electrogenic potassium transport in the lepidopteran midgut. A vacuolar-type electrogenic ATPase pumps protons across the apical membrane of the goblet cell, thus energizing electroneutral proton/potassium antiport. The result is a net active and electrogenic potassium flux.
Topics: Adenosine Triphosphatases; Adenosine Triphosphate; Aminacrine; Animals; Biological Transport, Active; Cations, Monovalent; Cell Membrane; Dicyclohexylcarbodiimide; Ethylmaleimide; Fluorescent Dyes; Hydrogen-Ion Concentration; Ion Channels; Isoxazoles; Larva; Lepidoptera; Membrane Potentials; Moths; Nucleotides; Potassium; Potassium Chloride; Protons; Vacuoles
PubMed: 2472389
DOI: No ID Found -
The Journal of General Physiology Apr 1985The time-, frequency-, and voltage-dependent blocking actions of several cationic drug molecules on open Na channels were investigated in voltage-clamped, internally...
The time-, frequency-, and voltage-dependent blocking actions of several cationic drug molecules on open Na channels were investigated in voltage-clamped, internally perfused squid giant axons. The relative potencies and time courses of block by the agents (pancuronium [PC], octylguanidinium [C8G], QX-314, and 9-aminoacridine [9-AA]) were compared in different intracellular ionic solutions; specifically, the influences of internal Cs, tetramethylammonium (TMA), and Na ions on block were examined. TMA+ was found to inhibit the steady state block of open Na channels by all of the compounds. The time-dependent, inactivation-like decay of Na currents in pronase-treated axons perfused with either PC, 9-AA, or C8G was retarded by internal TMA+. The apparent dissociation constants (at zero voltage) for interaction between PC and 9-AA with their binding sites were increased when TMA+ was substituted for Cs+ in the internal solution. The steepness of the voltage dependence of 9-AA or PC block found with internal Cs+ solutions was greatly reduced by TMA+, resulting in estimates for the fractional electrical distance of the 9-AA binding site of 0.56 and 0.22 in Cs+ and TMA+, respectively. This change may reflect a shift from predominantly 9-AA block in the presence of Cs+ to predominantly TMA+ block. The depth, but not the rate, of frequency-dependent block by QX-314 and 9-AA is reduced by internal TMA+. In addition, recovery from frequency-dependent block is not altered. Elevation of internal Na produces effects on 9-AA block qualitatively similar to those seen with TMA+. The results are consistent with a scheme in which the open channel blocking drugs, TMA (and Na) ions, and the inactivation gate all compete for a site or for access to a site in the channel from the intracellular surface. In addition, TMA ions decrease the apparent blocking rates of other drugs in a manner analogous to their inhibition of the inactivation process. Multiple occupancy of Na channels and mutual exclusion of drug molecules may play a role in the complex gating behaviors seen under these conditions.
Topics: Aminacrine; Animals; Axons; Cations, Monovalent; Cesium; Decapodiformes; Electrophysiology; Guanidines; Ion Channels; Pancuronium; Quaternary Ammonium Compounds; Sodium; Time Factors
PubMed: 2409221
DOI: 10.1085/jgp.85.4.603 -
International Journal of Molecular... May 2024While edible algae might seem low in fat, the lipids they contain are crucial for good health and preventing chronic diseases. This study introduces a binary matrix to...
While edible algae might seem low in fat, the lipids they contain are crucial for good health and preventing chronic diseases. This study introduces a binary matrix to analyze all the polar lipids in both macroalgae (Wakame-, Dulse-, and Nori- spp.) and microalgae (Spirulina-, and Chlorella-) using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). The key lies in a new dual matrix made by combining equimolar amounts of 1,5-diaminonaphthalene (DAN) and 9-aminoacridine (9AA). This combination solves the limitations of single matrices: 9AA is suitable for sulfur-containing lipids and acidic phospholipids, while DAN excels as an electron-transfer secondary reaction matrix for intact chlorophylls and their derivatives. By employing the equimolar binary matrix, a wider range of algal lipids, including free fatty acids, phospholipids, glycolipids, pigments, and even rare arsenosugarphospholipids were successfully detected, overcoming drawbacks related to ion suppression from readily ionizable lipids. The resulting mass spectra exhibited a good signal-to-noise ratio at a lower laser fluence and minimized background noise. This improvement stems from the binary matrix's ability to mitigate in-source decay effects, a phenomenon often encountered for certain matrices. Consequently, the data obtained are more reliable, facilitating a faster and more comprehensive exploration of algal lipidomes using high-throughput MALDI-MS/MS analysis.
Topics: Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Lipids; Seaweed; Microalgae; 2-Naphthylamine; Aminacrine; Pigments, Biological; Spirulina
PubMed: 38892117
DOI: 10.3390/ijms25115919 -
Journal of Applied Physiology... May 2003The purpose of the present investigation was to establish a method for estimating intracellular Ca(2+) concentrations ([Ca(2+)](i)) in isolated rat epitrochlearis...
The purpose of the present investigation was to establish a method for estimating intracellular Ca(2+) concentrations ([Ca(2+)](i)) in isolated rat epitrochlearis muscles. Epitrochlearis muscles excised from 4-wk-old male Sprague-Dawley rats were loaded with a fluorescent Ca(2+) indicator, fura 2-AM, for 60-90 min at 35 degrees C in oxygenated Krebs-Henseleit buffer. After fura 2 loading and subsequent 20-min incubation, the intensities of 500-nm fluorescence, induced by 340- and 380-nm excitation lights (F(total)340 and F(total)380), were measured. The fluorescences specific to fura-2 (F(fura 2)340 and F(fura 2)380) were calculated by subtracting the non-fura 2-specific component from F(total)340 and F(total)380, respectively. The ratio of F(fura 2)340 to F(fura 2)380 was calculated as R, and the change in the ratio from the baseline value (DeltaR) was used as an index of the change in [Ca(2+)](i). In resting muscle, DeltaR was stable for 60 min. Incubation for 20 min with caffeine (3-10 mM) significantly increased DeltaR in a concentration-dependent manner. Incubation with hypoxic Krebs-Henseleit buffer for 10-60 min significantly elevated DeltaR, depending on the duration of the incubation. Incubation with 50 microM N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide for 20 min significantly elevated DeltaR (P < 0.05). No significant increases in DeltaR were observed during incubation for 20 min with 2 mM 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside or with 2 mU/ml insulin. These results demonstrated that, by using the fura 2-AM fluorescence method, the changes in [Ca(2+)](i) can be monitored in the rat epitrochlearis muscle and suggest that the method can be utilized to observe quantitative information regarding [Ca(2+)](i) that may be involved in contraction- and hypoxia-stimulated glucose transport activity in skeletal muscle.
Topics: Aminacrine; Animals; Biological Transport; Caffeine; Calcium; Dantrolene; Fura-2; Glucose; Hypoxia; Ionomycin; Ionophores; Male; Muscle Contraction; Muscle, Skeletal; Phosphodiesterase Inhibitors; Rats; Rats, Sprague-Dawley; Stimulation, Chemical; Sulfonamides
PubMed: 12547839
DOI: 10.1152/japplphysiol.00780.2002 -
Cytometry. Part a : the Journal of the... Jan 2003Successful automated chromosome analysis requires the development of new techniques to increase and standardize chromosome length and improve banding patterns. (Comparative Study)
Comparative Study
BACKGROUND
Successful automated chromosome analysis requires the development of new techniques to increase and standardize chromosome length and improve banding patterns.
METHODS
Human and plant cells were pretreated with the DNA intercalator 9-aminoacridine (9-AMA), and chromosomes were stained with GTG and aceto-orcein banding techniques and investigated by an image analysis system.
RESULTS
The human optimal chromosome spreads with the 850 G-band resolution level, suitable for image analysis, were obtained by 9-AMA pretreatment for 1 h at a final concentration of 0.5-1 microg/ml, as compared with 600-700 bands after ethidium bromide treatment and about 400 bands without pretreatment. The best results for plant chromosomes were obtained after pretreatment with 1-2 microg/ml of 9-AMA for 12-24 h. The chromosomes elongated approximately 1.5-fold, and the resolution of chromosome banding patterns increased, reaching approximately 140 bands per haploid set in the case of camomile.
CONCLUSIONS
9-AMA is an efficient reagent for the standardization and increasing the resolution of chromosome banding patterns in human and plant chromosomes. It is extremely important for chromosome investigation in small plants.
Topics: Aminacrine; Cells, Cultured; Chromosome Banding; Chromosomes; DNA, Plant; Ethidium; Humans; Image Processing, Computer-Assisted; Lymphocytes; Reproducibility of Results
PubMed: 12500305
DOI: 10.1002/cyto.a.10002