Showing papers in "Biochimica et Biophysica Acta in 1974"

TL;DR: Analysis of the protein composition by sodium dodecylsulphate gel electrophoresis and determination of the capacities for binding of ATP and ouabain and for sodium-dependent phosphorylation show that the procedures lead to a true purification of the enzyme.

TL;DR: Compared to previously described methods for obtaining synaptic plasma-enriched fractions of equivalent purity, the procedure reported here is simpler, shorter, and of greater capacity.

TL;DR: Mechanisms of the polyene antibiotic induced permeability changes in membranes are proposed based on the analysis of the complexes of cholesterol, amphotericin B, nystatin, etruscomycin and pimaricin, which can be built with space-filling models.

TL;DR: In this paper, the ordering of the hydrocarbon chain interior of bilayer membranes has been calculated using the molecular field approximation developed in previous work on liquid crystals, and different statistical averages are evaluated by exact summation over all conformations of a single chain in the field due to neighboring molecules.

TL;DR: Fusion between vesicles prepared from individual or mixed phospholipid species was demonstrated by ultracentrifugation and gel-filtration techniques, electron microscopy and differential scanning calorimetry, and Ca2+ induced segregation of individual lipids to form separate domains within the vesicle membrane (phase separation).

TL;DR: A value of 3 · 10−12 cm2/s was derived from the experimental data as an upper limit for the diffusion coefficient of fluorescein isothiocyanate-labelled compounds in the erythrocyte membrane at 20°–23°C.

TL;DR: A rapid, highly reproducible, micro-incubation, direct thin-layer chromatographic assay for 3-hydroxy-3-methylglutaryl-CoA reductase is described, which accurately determines the rapid inactivation of reduct enzyme by MgATP and the low levels of reduCTase activity in cholesterol-treated L cells are accurately determined.

TL;DR: Action spectra and relative quantum efficiency measurements demonstrated the existence of both Photosystem I and Photosystem II in membrane fragments which contained chlorophyll a as the only significant light-absorbing pigment.

TL;DR: A new (optical) method of diffusion measurement is described which allows the determination of the coefficient of lateral diffusion, Ddiff, of aromatic molecules in the hydrophobic region of lipid bilayers using pyrene as a fluorescence probe.

TL;DR: A study was made of the reactions between the primary and secondary electron acceptors of Photosystem 2 by measurements of the increase of chlorophyll fluorescence induced in darkness by dithionite or 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU).

TL;DR: Only those sterols which had 3β-OH group, a planar molecule and hydrophobic side chain at C17 were able to interact with these polyene antibiotics and thereby enhance the membrane permeability.

TL;DR: A method is described for the rapid separation of mitochondria (plus other particulate components) from the soluble cytoplasm of isolated rat-liver cells and found that the pellet contained more than 90% of the total adenylate kinase and glutamate dehydrogenase activities and the supernatant at least 80%" of the lactate dehydration activity.

TL;DR: It is interesting to note that the current membrane model accentuates the fluidity of the membrane, which phospholipids undergo a rapid lateral diffusion within the two monolayers of the bilayer.

TL;DR: The widely assumed correspondence between fluorescence and photochemistry in photosynthetic systems has recently been challenged by observations on the triplet state of bacteriochlorophyll in reaction centres of Rhodopseudomonas spheroides, and a precise determination of the quantum efficiency is conducted.

TL;DR: In this paper, the complete absorption difference spectrum of the primary electron acceptor of Photosystem II has been measured at room temperature in subchloroplast fragments prepared with deoxycholate and the shape and amplitude of the spectrum indicate that the primary reaction involves the reduction of one bound plastoquinone molecule per reaction center to its semiquinone anion.

TL;DR: The assay for ribulosebisphosphate carboxylase activity, by spectrophotometric measurement of NADH oxidation with a coupled enzyme system, is greatly improved by addition of an ATP-regenerating system.

TL;DR: Washed membranes from pea chloroplasts can be resolved into at least 21 protein bands on sodium dodecylsulphate polyacrylamide gels, with molecular weights ranging from 13 000 to over 100 000, but the identity of these proteins is unknown.

TL;DR: Glutathione peroxidase (GSH:H2O2 oxidoreductase, EC 1.11.1.9) was purified 400-fold from rat liver by fractionation with (NH4)2SO4 and chromatography with DEAE-cellulose, Sepha dex G-200 and Sephadex A-50 in the presence of 0.5 mM GSH.

TL;DR: It is demonstrated that the transition temperature from the liquid-crystalline to gel state of a synthetic phosphatidylglycerol is influenced by pH, Ca2+ and A1 basic protein from myelin.

TL;DR: It is hypothesized that the membrane intercalated particles of human erythrocyte ghost membranes represent an amphipatic structure (“permeaphore”) which topologically and structurally interrupts hydrophobic bilayer membrane domains.

TL;DR: It is demonstrated that the presence of the unstirred layer introduces major artifacts into the determination of Km and Jmax (maximal transport rate) values for active transport processes.

TL;DR: It is shown that the relationship between the partition coefficient P and the water solubility S, holds for the solutes investigated here and offers a simple way of assessing the anaesthetic potency of a wide range of compounds.

TL;DR: The results suggest that the enzyme unit binding one molecule of ATP or ouabain contains two chains of large polypeptide and that both chains are phosphorylation from ATP in the presence of Mg2+ and Na+.

TL;DR: EPR signals observed with the enzyme between 6 and 100 °K at various states of oxidation and at different conditions of pH and presence of solutes are described in detail and the quantities of paramagnetic species represented by these signals are estimated.