scholarly journals Binding of ADP to rat liver cytosolic proteins and its influence on the ratio of free ATP/free ADP

1989 ◽  
Vol 259 (1) ◽  
pp. 117-124 ◽  
Author(s):  
S Mörikofer-Zwez ◽  
P Walter
Keyword(s):  
Ethylene Glycol ◽  
Rat Liver ◽  
Binding Sites ◽  
Dissociation Constants ◽  
Cellular Protein ◽  
Poly Ethylene Glycol ◽  
Cytosolic Proteins ◽  
Kd Values ◽  
Cytosolic Extract ◽  
Poly Ethylene

In a cytosolic extract from rat liver, the number and the concentration of ADP-binding sites as well as their dissociation constants were determined by using the rate-of-dialysis technique. Interfering cytosolic adenylate kinase was extracted from the cytosol by affinity chromatography on Ap5A-agarose, and remaining traces of enzyme activity were inhibited with (+)-catechin. Binding of ADP to cytosolic proteins was increased by poly(ethylene glycol) and decreased by EDTA. The effect of 0.1 mM-EDTA could be reversed by addition of equimolar concentrations of Mn2+ or Mg2+. In presence of 5% poly(ethylene glycol), added to increase local protein concentration, two binding sites for ADP were observed, with KD values of 1.9 microM (site I) and 10.8 microM (site II). The concentration of these binding sites, when extrapolated to cellular protein concentrations, were 30 microM (site I) and 114 microM (site II). It is concluded that a minimum of about 50% of total cytosolic ADP is bound to proteins, and that the ratio of free ATP/free ADP is at least twice that of total ATP/total ADP.

scholarly journals The mechanism of action of GTP on Ca2+ efflux from rat liver microsomal vesicles

1987 ◽  
Vol 244 (1) ◽  
pp. 87-92 ◽  
Author(s):  
A P Dawson ◽  
G Hills ◽  
J G Comerford
Keyword(s):  
Electron Microscopy ◽  
Light Scattering ◽  
Ethylene Glycol ◽  
Rat Liver ◽  
Mechanism Of Action ◽  
Vesicle Fusion ◽  
Fusion Process ◽  
Poly Ethylene Glycol ◽  
Rapid Production ◽  
Poly Ethylene

1. Guanosine 5′-[gamma-thio]triphosphate (GTP[S]), if added before GTP, blocks both Ca2+ efflux promoted by GTP and the effect of GTP on enhancement of inositol 1,4,5-triphosphate (IP3)-promoted Ca2+ release from preloaded microsomal vesicles. If, however, GTP[S] is added after GTP, it does not reverse the Ca2+ efflux promoted by GTP, nor does it inhibit IP3-promoted Ca2+ release. 2. The effect of GTP in enhancing IP3-promoted Ca2+ release is maintained after washing the microsomal vesicles free of added GTP. After this treatment, enhancement of IP3-promoted Ca2+ efflux can be observed in the absence of poly(ethylene glycol). 3. Electron microscopy shows that during GTP treatment of microsomal vesicles there is rapid production of very large vesicular structures, apparently produced by fusion of smaller vesicles. 4. Light-scattering changes are detectable during the fusion process. 5. Both Ca2+ efflux promoted by GTP and the enhancement of IP3-promoted Ca2+ release seen in the presence of GTP can probably be attributed to GTP-dependent vesicle fusion.

scholarly journals Interactions of Inositol 1,4,5-Trisphosphate (IP3) Receptors with Synthetic Poly(ethylene glycol)-linked Dimers of IP3Suggest Close Spacing of the IP3-binding Sites

2002 ◽  
Vol 277 (43) ◽  
pp. 40290-40295 ◽  
Author(s):  
Andrew M. Riley ◽  
Stephen A. Morris ◽  
Edmund P Nerou ◽  
Vanessa Correa ◽  
Barry V. L. Potter ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Binding Sites ◽  
Ip3 Receptors ◽  
Poly Ethylene Glycol ◽  
Close Spacing ◽  
Inositol 1,4,5 Trisphosphate ◽  
Poly Ethylene

scholarly journals Subcellular fractionation of rat liver homogenates using two-polymer phase systems in a toroidal-coil centrifuge

1984 ◽  
Vol 217 (3) ◽  
pp. 751-759 ◽  
Author(s):  
D Heywood-Waddington ◽  
I A Sutherland ◽  
W B Morris ◽  
T J Peters
Keyword(s):  
Plasma Membrane ◽  
Ethylene Glycol ◽  
Rat Liver ◽  
Flow Rate ◽  
Marker Enzyme ◽  
Poly Ethylene Glycol ◽  
Lower Phase ◽  
Liver Homogenates ◽  
Toroidal Coil ◽  
Poly Ethylene

The principal organelles of rat liver homogenates were fractionated by two-phase partition chromatography using toroidal-coil centrifugation with a mixture of dextran T 500 and poly(ethylene glycol) 6000 in 0.26 M-sucrose containing 10 mM-sodium phosphate/phosphoric acid buffer, pH 7.4. The effects of varying the following parameters on organelle elution profiles, as reflected by their marker-enzyme activities, were studied: centrifuge speed; the composition and relative proportion of dextran-rich and poly(ethylene glycol)-rich phases in the eluent; flow rate; sample volume; homogenate concentration; helix diameter; tubing bore and the number of loops in the coil. Optimal resolution of the organelles was achieved with a toroidal coil of internal diameter 1.07 mm with a 4.55 mm helix diameter on a 0.42 m-diameter rotor running at 1000 rev./min. The eluent was prepared by combining, in a ratio of 93:7 (v/v), the poly(ethylene glycol)-rich upper phase and dextran-rich lower phase obtained from a phase mixture containing 3.3% (w/w) dextran and 5.4% (w/w) poly(ethylene glycol). The flow rate of the eluent was 14ml/h. Optimal conditions for separation of the organelles were evaluated. Resolution of plasma membrane and lysosomes was achieved. Separation of endoplasmic reticulum, which showed marked heterogeneity, from plasma membrane was also demonstrated. DNA and marker enzymes for peroxisomes, mitochondria and cytosol showed distinct elution profiles.

PIEZOELECTRIC PROPERTIES OF POLY(3-HYDROXYBUTYRATE-CO-3-HEDROXYBUTYRATE)-CO-POLY(ETHYLENE GLYCOL) PRODUCED BY CONTROLLED MICROBIOLOGICAL BIOSYNTHESIS

2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Anton Bonartsev ◽  
Vera Voinova ◽  
Elizaveta Akoulina ◽  
Andrey Dudun ◽  
Irina Zharkova ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Piezoelectric Properties ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

Thermosensitives hydrogels based on poly (ethylene glycol): I. Synthesis, characterization and release

2007 ◽  
Vol 32 (5) ◽  
pp. 431-446 ◽  
Author(s):  
Tahar Bartil ◽  
Mahmoud Bounekhel ◽  
Cedric Calberg ◽  
Robert Jerome
Keyword(s):  
Ethylene Glycol ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

Quantifying Heart Valve Interstitial Cell Contractile State Using Highly Tunable Poly(Ethylene Glycol) Hydrogels

2019 ◽  
Author(s):  
Alex Khang ◽  
Andrea Gonzalez Rodriguez ◽  
Megan E. Schroeder ◽  
Jacob Sansom ◽  
Emma Lejeune ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Heart Valve ◽  
Interstitial Cell ◽  
Poly Ethylene Glycol ◽  
Contractile State ◽  
Poly Ethylene
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