Disease relevance of Pyranine

• The experimental system selected for testing the accuracy of this concept was the reversible dissociation of a proton from a single pyranine molecule (8-hydroxypyrene-1,2,3-trisulfonate) bound by electrostatic forces inside the PhoE ionic channel of the Escherichia coli outer membrane [1].

High impact information on Pyranine

• The kinetics of proton release into the water phase was observed with the optical pH indicator pyranine [2].
• The pyranine study is complemented by the use of vibronic side band luminescence from the gadolinium cation that directly exposes the changes in hydrogen bonding between first and second shell waters as a function of added osmolytes [3].
• Additional evidence that the Ca2+ pump of sarcoplasmic reticulum operated as a Ca2(+)-H+ countertransport was provided by measurements of ATP-dependent intraliposomal alkalinization using entrapped 8-hydroxyl-1,3,6-pyrene trisulfonate (pyranine) and accumulation of the weak acid acetate [4].
• We have investigated the permeability of protein-free myelin lipid liposomes to inorganic lead by using the fluorescent probes fura-2, oxonol V, pyranine, and carboxyfluorescein [5].
• We also study the methoxy derivative of pyranine (MPTS), which is similar in electronic structure but does not have the photoacidity property [6].

Biological context of Pyranine

• Endocytosis and intracellular fate of liposomes using pyranine as a probe [7].
• Time resolved fluorimetry was employed to monitor the geminate recombination between proton and excited pyranine anion locked, together with less than 30 water molecules, inside the heme binding site of Apomyoglobin (sperm whale) [8].
• In this study, membrane potential (V(m)) and pH(i) were measured simultaneously in chemosensitive locus coeruleus (LC) neurons from neonatal rat brain stem slices using whole cell pipettes and the pH-sensitive fluorescent dye pyranine [9].
• We tested the hypothesis that oxidative stress stimulates SC neurons by a mechanism independent of intracellular pH (pH(i)). pH(i) was measured by using ratiometric fluorescence imaging microscopy, utilizing either the pH-sensitive fluorescent dye BCECF or, during whole cell recordings, pyranine in SC neurons in brain stem slices from rat pups [10].
• The paracellular permeability characteristics were determined in terms of changes in the permeability to the polar acid pyranine (Ppyr) and as changes in the transendothelial electrical resistance (RTE) [11].

Anatomical context of Pyranine

• The membranes were pulsed by protons discharged from photoexcited pyranine [Nachliel, E., Gutman, M., Kiryati, S., and Dencher, N.A. (1996) Proc. Nat Acad. Sci. U.S.A. 93, 10747-10752) [12].
• The excited-state proton emitter, pyranine (8-hydroxypyrene-1,3,6-trisulfonate), was introduced into the inner aqueous space of inside-out submitochondrial particles (SMP) [13].
• (iv) Pyranine introduced by electroporation seemed to be located in the cytoplasm and to avoid the vacuole, and therefore it probably measured actual cytoplasmic pH [14].
• In the rabbit eye, pyranine in the cornea and anterior chamber was observed to undergo easily measurable changes in fluorescent ratios associated with lid closure and contact lens wear, indicating its sensitivity to mild changes in pH [15].
• With the latter, we found that either impalement with microelectrodes or electrophoretic microinjection of two dyes, Lucifer Yellow CH or pyranine , into the inner space have no effect on the phosphorylative capacity of mitochondria or mitoplasts [16].

Associations of Pyranine with other chemical compounds

• Similar rates of desorption are observed for the transfer of oleic acid from the three donors to pyranine-containing EPC vesicles with rate constants k(1) ranging from 0.4 to 1.3 s(-1) [17].
• Na+ accumulation was assayed with 22Na+; deltapsi generation was detected by recording absorption changes of oxonol VI; H+ efflux was monitored as an increase in fluorescence intensity of the pH indicator pyranine loaded into the vesicles [18].
• Initiation of respiration upon the addition of 20 microM ubiquinone-1 to proteoliposomes loaded with the pH-sensitive dye pyranine resulted in an immediate alkalization of the vesicle lumen by an average pH change of 0.11 unit [19].
• Purified wild-type M2 protein and an amantadine-resistant mutant M2 (M2 delta) with a deletion in the trans-membrane domain (amino acids 28 to 31) were incorporated into lipid vesicles, which were loaded with the fluorescent pH indicator pyranine [20].
• We now show that the pH probes pyranine and quinacrine behave similarly to NPN [21].

Gene context of Pyranine

• The reconstituted enzyme catalyzed CaM-stimulated 45Ca(2+) accumulation and H(+) ejection, monitored by the increase of fluorescence of the pH probe pyranine entrapped in the liposomal lumen during reconstitution [22].
• METHODS: Cervical cells (ECE16-1, Caski, and HT3) were grown on filters, and transepithelial electrical conductance (GT) and the permeability to pyranine (PPyr) were determined [23].
• Proteoliposomes containing cytochrome c oxidase and an internally trapped fluorescent pH probe (pyranine) were used to monitor respiration-dependent internal alkalinization and membrane potential formation [24].
• We describe a strategy for intracellular delivery of pyranine based on the reversible activation of purinergic P2x7 receptors, which allow permeation of the dye into otherwise intact cells [25].
• Liposomes of egg PC/PG (8:2, mol/mol) were multilabelled with PBFI, pyranine and oxonol VI, fluorescent probes for, respectively, K+, H+ and membrane potential [26].

Analytical, diagnostic and therapeutic context of Pyranine

• The presence of rosettasomes did not significantly change the transition temperature of liposomes, as indicated by differential scanning calorimetry, or the proton permeability of liposomes, as indicated by pyranine fluorescence [27].
• As a result, it is possible to form vesicles in the presence of pyranine which, after removal of external probe by gel filtration, contain pyranine entrapped within the internal aqueous compartment [28].
• Pyranine (8-hydroxyl-1,3,6-pyrene-trisulfonate) was used as a pH probe to show that proton release to the bulk phase results from the SR-I587 to S373 photoconversion, but only in the absence of transducer [29].
• Proton pumping and the internal pH of yeast cells, measured with pyranine introduced by electroporation [14].
• The electric potential across the membrane was measured with microelectrodes and the pH of the internal space was calculated from the fluorescence of the pH indicator pyranine [30].

References