Rapid development of vasopressin-induced hydroosmosis in kidney collecting tubules measured by a new fluorescence technique.
AuthorsKuwahara M, Berry CA, Verkman AS
JournalBiophys J
PubMed ID3224145
'The pre-steady-state kinetics of the vasopressin-induced increase in collecting tubule osmotic water permeability (Pf) has been measured by a new fluorescence technique. Isolated cortical collecting tubules (CCT) from rabbit kidney were perfused with physiological buffers containing the impermeant fluorophores fluorescein sulfonate (FS) and pyrenetetrasulfonic acid (PTSA). Tubules were subject to ... More
Preparation of giant liposomes in physiological conditions and their characterization under an optical microscope.
AuthorsAkashi K, Miyata H, Itoh H, Kinosita K
JournalBiophys J
PubMed ID8968594
'Unilamellar liposomes with diameters of 25-100 microns were prepared in various physiological salt solutions, e.g., 100 mM KCl plus 1 mM CaCl2. Successful preparation of the giant liposomes at high ionic strengths required the inclusion of 10-20% of a charged lipid, such as phosphatidylglycerol, phosphatidylserine, phosphatidic acid, or cardiolipin, in ... More
Eserine and other tertiary amine interactions with Torpedo acetylcholine receptor postsynaptic membrane vesicles.
AuthorsKawai H, Carlson BJ, Okita DK, Raftery MA
JournalBiochemistry
PubMed ID9890891
'Interaction of the tertiary amines, arecolone, eserine (physostigmine), (+)-epibatidine, and (+/-)-epibatidine, with Torpedo nicotinic acetylcholine receptor-enriched membrane vesicles was investigated to characterize their action on the receptor, using stopped-flow thallium (I)-flux spectrofluorimetry. Arecolone, (+)-epibatidine, and (+/-)-epibatidine were agonists with activation constants of 390, 19, and 39 microM, respectively. Eserine was ... More
Determination of ion permeability by fluorescence quenching.
AuthorsGarcia AM
JournalMethods Enzymol
PubMed ID1382199
Continuous monitoring of transport by fluorescence on cells and vesicles.
AuthorsEidelman O, Cabantchik ZI
JournalBiochim Biophys Acta
PubMed ID2686755
Fluorescence techniques are gaining wider applicability in the field of membrane transport due to their high temporal resolution, modest demand for biological material and the kinetic information which is made available by fluorescence tracings. The development of novel fluorescent substrates for particular transport systems and of novel fluorescent indicators for ... More
Channel-mediated monovalent cation fluxes in isolated sarcoplasmic reticulum vesicles.
AuthorsGarcia AM, Miller C
JournalJ Gen Physiol
PubMed ID6330279
The permeability of isolated sarcoplasmic reticulum (SR) vesicles to monovalent cations was studied using a stopped-flow fluorescence quenching technique that permits the measurement of ion fluxes on a millisecond time scale. Approximately 70% of the SR vesicles carry a cation conductance pathway mediating fluxes of Tl+, K+, Na+, and Li+, ... More
Organization and dynamics of pyrene and pyrene lipids in intact lipid bilayers. Photo-induced charge transfer processes.
AuthorsBarenholz Y, Cohen T, Korenstein R, Ottolenghi M
JournalBiophys J
PubMed ID1883931
The dynamics of fluorescence quenching and the organization of a series of pyrene derivatives anchored in various depths in bilayers of phosphatidylcholine small unilamellar vesicles was studied and compared with their behavior in homogeneous solvent systems. The studies include characterization of the environmental polarity of the pyrene fluorophore based on ... More
Phase-lifetime spectrophotometry of deoxycholate-purified bacteriorhodopsin reconstituted into asolectin vesicles.
AuthorsKrupinski J, Hammes GG
JournalBiochemistry
PubMed ID4074733
A rapid reconstitution procedure has been developed to insert deoxycholate-purified bacteriorhodopsin (bR) into asolectin vesicles. The procedure relies on the ability of the hydrophobic resin Bio-Beads SM-2 to remove octyl glucoside from a mixture of deoxycholate-purified bR, asolectin, and the detergent. Light-dependent acidification of the vesicle interior is observed with ... More
Probing the diphosphoglycerate binding pocket of HbA and HbPresbyterian (beta 108Asn --> Lys).
AuthorsGottfried DS, Manjula BN, Malavalli A, Acharya AS, Friedman JM
JournalBiochemistry
PubMed ID10471280
HbPresbyterian (beta 108Asn --> Lys, HbP) contains an additional positive charge (per alpha beta dimer) in the middle of the central cavity and exhibits a lower oxygen affinity than wild-type HbA in the presence of chloride. However, very little is known about the molecular origins of its altered functional properties. ... More