Diffusion of Water Soluble Spin Labels in the Aqueous Phase of Mammalian Cells

1981 ◽  
Author(s):  
Andrea M. Mastro ◽  
Alec D. Keith
Keyword(s):  
Aqueous Phase ◽  
Mammalian Cells ◽  
Water Soluble ◽  
Spin Labels

BODIPY Fluorophores for Membrane Potential Imaging

2019 ◽  
Author(s):  
Jenna Franke ◽  
Benjamin Raliski ◽  
Steven Boggess ◽  
Divya Natesan ◽  
Evan Koretsky ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Water Solubility ◽  
Water Soluble ◽  
Voltage Sensitivity ◽  
Chemical Transformations ◽  
Direct Modification ◽  
Biological Compatibility ◽  
Meso Position ◽  
Ionizable Groups ◽  
Boron Center

Fluorophores based on the BODIPY scaffold are prized for their tunable excitation and emission profiles, mild syntheses, and biological compatibility. Improving the water-solubility of BODIPY dyes remains an outstanding challenge. The development of water-soluble BODIPY dyes usually involves direct modification of the BODIPY fluorophore core with ionizable groups or substitution at the boron center. While these strategies are effective for the generation of water-soluble fluorophores, they are challenging to implement when developing BODIPY-based indicators: direct modification of BODIPY core can disrupt the electronics of the dye, complicating the design of functional indicators; and substitution at the boron center often renders the resultant BODIPY incompatible with the chemical transformations required to generate fluorescent sensors. In this study, we show that BODIPYs bearing a sulfonated aromatic group at the meso position provide a general solution for water-soluble BODIPYs. We outline the route to a suite of 5 new sulfonated BODIPYs with 2,6-disubstitution patterns spanning a range of electron-donating and -withdrawing propensities. To highlight the utility of these new, sulfonated BODIPYs, we further functionalize them to access 13 new, BODIPY-based voltage-sensitive fluorophores. The most sensitive of these BODIPY VF dyes displays a 48% ΔF/F per 100 mV in mammalian cells. Two additional BODIPY VFs show good voltage sensitivity (≥24% ΔF/F) and excellent brightness in cells. These compounds can report on action potential dynamics in both mammalian neurons and human stem cell-derived cardiomyocytes. Accessing a range of substituents in the context of a water soluble BODIPY fluorophore provides opportunities to tune the electronic properties of water-soluble BODIPY dyes for functional indicators.

Thermotropic lipid and protein transitions in Chinese hamster lung cell membranes: relationship to hyperthermic cell killing

1983 ◽  
Vol 61 (6) ◽  
pp. 421-427 ◽  
Author(s):  
James R. Lepock ◽  
Kwan-Hon Cheng ◽  
Hisham Al-Qysi ◽  
Jack Kruuv
Keyword(s):  
Mammalian Cells ◽  
Plasma Membranes ◽  
Chinese Hamster ◽  
Cell Killing ◽  
Water Soluble ◽  
Growth Data ◽  
Protein Fluorescence ◽  
Polar Groups ◽  
Spin Resonance ◽  
Intrinsic Protein Fluorescence

Exposure of mammalian cells to hyperthermic temperatures (ca. 41–45 °C) appears to act as a direct or triggering effect to produce some later response such as cell death, thermotolerance, or heat-shock protein synthesis. The high activation energy of cell killing indicates that the direct effect of hyperthermia might be a thermotropic transition in some cellular component, for this particular response. Both hyperthermic survival and growth data imply that the temperature for the onset of hyperthermic cell killing is 40–41.5 °C for Chinese hamster lung V79 cells. Studies using the electron spin resonance label 2,2-dimethyl-5-dodecyl-5-methyloxazolidine-N-oxide and the fluorescent probe 1,6-diphenyl-1,3,5-hexatriene show the existence of lipid transitions at approximately 7–8 and 23–36 °C (or a broad transition between these temperatures) in mitochondria and whole cell homogenates, that correlate well with changes in growth and hypothermic killing. No lipid transition was detected near 40–41.5 °C that could correlate with hyperthermic killing in either mitochondrial or plasma membranes, but measurements of intrinsic protein fluorescence and protein fluorophore to trans-paranaric acid energy transfer demonstrate the existence of an irreversible transition in protein structure or arrangement above ca. 40 °C in both mitochondrial and plasma membranes. This transition is due to protein rearrangement and (or) unfolding such that there is increased exposure of protein tryptophan and tyrosine residues to polar groups and to paranaric acid. The strength of the transition implies that a significant fraction of total membrane protein is involved in this transition, which may be analogous to the heat-induced denaturation of water-soluble proteins. This alteration in membrane structure above ca. 40 °C could cause many of the observed changes in plasma membrane and mitochondrial function, which may further be involved in cellular responses to hyperthermia.

New water soluble chelating phosphines for aqueous phase catalysis

1997 ◽  
Vol 124 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Hao Ding ◽  
Jianxing Kang ◽  
Brian E. Hanson ◽  
Christian W. Kohlpaintner
Keyword(s):  
Aqueous Phase ◽  
Water Soluble ◽  
Chelating Phosphines ◽  
Aqueous Phase Catalysis

scholarly journals Activity of Indenoisoquinolines against African Trypanosomes

2008 ◽  
Vol 53 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Rahul P. Bakshi ◽  
Dongpei Sang ◽  
Andrew Morrell ◽  
Mark Cushman ◽  
Theresa A. Shapiro
Keyword(s):  
Anticancer Agents ◽  
Mammalian Cells ◽  
Sleeping Sickness ◽  
Water Soluble ◽  
African Trypanosomes ◽  
In Vivo Experiments ◽  
Topoisomerase Ib ◽  
Topoisomerase Poisons

ABSTRACT African trypanosomiasis (sleeping sickness), caused by protozoan Trypanosoma brucei species, is a debilitating disease that is lethal if untreated. Available drugs are antiquated, toxic, and compromised by emerging resistance. The indenoisoquinolines are a class of noncamptothecin topoisomerase IB poisons that are under development as anticancer agents. We tested a variety of indenoisoquinolines for their ability to kill T. brucei. Indenoisoquinolines proved trypanocidal at submicromolar concentrations in vitro. Structure-activity analysis yielded motifs that enhanced potency, including alkylamino substitutions on N-6, methoxy groups on C-2 and C-3, and a methylenedioxy bridge between C-8 and C-9. Detailed analysis of eight water-soluble indenoisoquinolines demonstrated that in trypanosomes the compounds inhibited DNA synthesis and acted as topoisomerase poisons. Testing these compounds on L1210 mouse leukemia cells revealed that all eight were more effective against trypanosomes than against mammalian cells. In preliminary in vivo experiments one compound delayed parasitemia and extended survival in mice subjected to a lethal trypanosome challenge. The indenoisoquinolines provide a promising lead for the development of drugs against sleeping sickness.

scholarly journals Explicit modeling of volatile organic compounds partitioning in the atmospheric aqueous phase

2013 ◽  
Vol 13 (2) ◽  
pp. 1023-1037 ◽  
Author(s):  
C. Mouchel-Vallon ◽  
P. Bräuer ◽  
M. Camredon ◽  
R. Valorso ◽  
S. Madronich ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Water Content ◽  
Gas Phase ◽  
Aqueous Phase ◽  
Water Soluble ◽  
Chemical Mechanism ◽  
Organic Species ◽  
Cloud Water Content ◽  
Isoprene Oxidation

Abstract. The gas phase oxidation of organic species is a multigenerational process involving a large number of secondary compounds. Most secondary organic species are water-soluble multifunctional oxygenated molecules. The fully explicit chemical mechanism GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere) is used to describe the oxidation of organics in the gas phase and their mass transfer to the aqueous phase. The oxidation of three hydrocarbons of atmospheric interest (isoprene, octane and α-pinene) is investigated for various NOx conditions. The simulated oxidative trajectories are examined in a new two dimensional space defined by the mean oxidation state and the solubility. The amount of dissolved organic matter was found to be very low (yield less than 2% on carbon atom basis) under a water content typical of deliquescent aerosols. For cloud water content, 50% (isoprene oxidation) to 70% (octane oxidation) of the carbon atoms are found in the aqueous phase after the removal of the parent hydrocarbons for low NOx conditions. For high NOx conditions, this ratio is only 5% in the isoprene oxidation case, but remains large for α-pinene and octane oxidation cases (40% and 60%, respectively). Although the model does not yet include chemical reactions in the aqueous phase, much of this dissolved organic matter should be processed in cloud drops and modify both oxidation rates and the speciation of organic species.

Selective Transport of Water-Soluble Proteins from Aqueous to Ionic Liquid Phase via a Temperature-Sensitive Phase Change of These Mixtures

2012 ◽  
Vol 65 (11) ◽  
pp. 1548 ◽  
Author(s):  
Yuki Kohno ◽  
Nobuhumi Nakamura ◽  
Hiroyuki Ohno
Keyword(s):  
Phase Change ◽  
Aqueous Phase ◽  
Selective Dissolution ◽  
Selective Extraction ◽  
Soluble Proteins ◽  
Water Soluble ◽  
Temperature Sensitive ◽  
Salting Out ◽  
Key Factor ◽  
The Difference

Mixtures of some ionic liquids (ILs) and water show reversible phase change between a homogeneous mixture and phase-separated state by a small change in temperature. Some water-soluble proteins have been migrated from the aqueous to the IL phase. When tetrabutylphosphonium 2,4,6-trimethylbenzenesulfonate was used as an IL, cytochrome c (Cyt.c) was found to be extracted from the water phase to the IL phase. Conversely, both horseradish peroxidase (HRP) and azurin remained in the aqueous phase. This selective extraction was comprehended to be due to the difference in solubility of these proteins in both phases. The separated aqueous phase contained a small amount of IL, which induced the salting-out of Cyt.c. On the other hand, condensed IL phase promoted the salting-in of Cyt.c. As a result, Cyt.c was preferably dissolved in the hydrated IL phase rather than aqueous phase. In the case of HRP, there was only a salting-out profile upon increasing the concentration of IL, which induced selective dissolution of HRP in the aqueous phase. These results clearly suggest that the profile of salting-out and salting-in for proteins is the key factor to facilitate the selective extraction of proteins from aqueous to the IL phase.

scholarly journals The activity of superoxide-dismutase in animal cell culture CHO-K1 after treatment with fullerenol and mytomicine C

2009 ◽  
Vol 63 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Visnja Bogdanovic ◽  
Marija Slavic ◽  
Jasminka Mrdjanovic ◽  
Slavica Solajic ◽  
Aleksandar Djordjevic
Keyword(s):  
Superoxide Dismutase ◽  
Mammalian Cells ◽  
Animal Cell ◽  
Water Soluble ◽  
Cytotoxic Agents ◽  
Antioxidant Defenses ◽  
Free Radical Scavengers ◽  
Sod Activity

Eukaryotic cell survives in predominantly reduced conditions. Homeostasis of cellular redox system is an imperative of cell surviving and its normal metabolism. ROS are well recognized for playing a dual role as both deleterious and beneficial species, since they can be either harmful or beneficial to living systems. These species are mutagenic compounds known to lead to DNA damage, favor cell transformation, and contribute to the development of a variety of malignant diseases. All the effects of oxidants are influenced by the cellular antioxidant defenses. This multilayer system consists of low molecular weight components and several antioxidant enzymes. Superoxide dismutases (SODs) are the only enzymes dismuting superoxide radicals. Mitomycin C, a cross-linking agent, demonstrated genotoxicity in all in vitro and in vivo test systems in mammalian cells and animals. Water-soluble fullerenes are well known as cytotoxic agents for many cell lines in vitro. At the other side, fullerenols are good free radical scavengers and antioxidants both in vitro and in vivo. This paper investigates the effects of fullerenol on survival and fullerenol/ /mytomicine (MMC) treatment on superoxide-dismutase (SOD) activity in CHO-K1 cells. Samples were treated 3 and 24 h with fullerenol (C60(OH)24) at concentration range 0.01-0.5 mg/mL and survival was monitored with dye exclusion test (DET). The activity of total SOD was estimated in samples treated with chosen concentrations of fullerenol and MMC (0.5 and 0.1 mg/mL) after 3 and 24 h of cell incubation. Increasing of C60(OH)24 concentration leads to decreasing of percent of surviving cells 3 and 24 h after incubation. The activity of total SOD enhanced with higher concentration of fullerenol, while decreased in the highest concentration at both experimental points. In samples treated with MMC, as well as in samples treated with fullerenol (0.0625 mg/mL) + MMC was noticed boost in total SOD activity in comparison with controls. Treatment with fullerenol decreased SOD activity in rest of samples treated with MMC. Decreased activity of superoxide-dismutase in almost all samples treated with fullerenol and MMC might be contributed to antioxidative properties of fullerenol. Increased enzyme level at concentration of 0.0625 mg/mL may be due to its prooxidative activity.

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