Asymmetry of the chloride transport system in human erythrocyte ghosts

1978 ◽  
Vol 375 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Klaus F. Schnell ◽  
Elisabeth Besl ◽  
Annette Manz
Keyword(s):  
Transport System ◽  
Human Erythrocyte ◽  
Chloride Transport ◽  
Erythrocyte Ghosts

Lead and calcium transport in human erythrocyte

1999 ◽  
Vol 18 (5) ◽  
pp. 327-332 ◽  
Author(s):  
J V Calderón-Salinas ◽  
M A Quintanar-Escorcia ◽  
M T González-Martínez ◽  
C E Hernández-Luna
Keyword(s):  
Transport System ◽  
Human Erythrocyte ◽  
Calcium Transport ◽  
Human Erythrocytes ◽  
The Other ◽  
Erythrocyte Ghosts ◽  
Passive Transport ◽  
Ca Uptake

In this paper we report the lead (Pb) and calcium (Ca) uptake by erythrocyte ghosts. In both cases the transport was carried out by a passive transport system with two kinetic components (Michaelis-Menten and Hill). Pb and Ca were capable of inhibiting the transport of the other metal in a non-competitive way. Under hyperpolarization, the uptakes of Ca and Pb were enhanced and the Michaelis-Menten component prevailed. Both Ca and Pb uptakes were inhibited by N-ethyl-maleimide to the same extent. These results indicate that Pb and Ca share the same permeability pathway in human erythrocytes and that this transport system is electrogenic.

scholarly journals Reconstitution of the Ca2+-transport system of human erythrocytes

1980 ◽  
Vol 188 (1) ◽  
pp. 47-54 ◽  
Author(s):  
K Gietzen ◽  
S Seiler ◽  
S Fleischer ◽  
H U Wolf
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Transport System ◽  
Human Erythrocyte ◽  
Room Temperature ◽  
Proteinase Inhibitors ◽  
Membrane Vesicles ◽  
Tween 20 ◽  
Erythrocyte Ghosts ◽  
Lipid Ratio

The (Ca2+ + Mg2+)-dependent ATPase of human erythrocyte ‘ghosts’ was solubilized and reconstituted to form membranous vesicles capable of energized Ca2+ accumulation. The erythrocyte ‘ghosts’ for this purpose were prepared by using isoosmotic freeze-haemolysis in the presence of Tween 20 and proteinase inhibitors to stabilize the preparation. The reconstitution procedure is similar to that developed by Meissner & Fleischer [(1974) J. Biol. Chem. 249, 302-309] for skeletal-muscle sarcoplasmic-reticulum in that: (1) deoxycholate is used for the solubilization of the membrane; (2) controlled dialysis at near room temperature, rather than 0 degree C, is required in order to obtain a functional preparation capable of Ca2+ accumulation; and (3) membrane vesicles can be reassembled with protein/lipid ratio (approx. 60% protein and 40% lipid) similar to that of the original membrane.

scholarly journals Active transport of GSSG from reconstituted erythrocyte ghosts

Blood ◽  
1975 ◽  
Vol 46 (1) ◽  
pp. 111-117 ◽  
Author(s):  
J Prchal ◽  
SK Srivastava ◽  
E Beutler
Keyword(s):  
Active Transport ◽  
Transport System ◽  
Concentration Gradient ◽  
Human Erythrocyte ◽  
Red Cells ◽  
Intracellular Concentration ◽  
Maximal Velocity ◽  
Erythrocyte Ghosts ◽  
The Relationship

Abstract Human erythrocyte ghosts were loaded with 35S-labeled GSSG and with a sucrose marker, and the transport of GSSG to the suspending medium was studied. GSSG transport from ghosts occurred only when ATP was also present in the ghosts, proceeded against a concentration gradient, and was inhibited by fluoride. The rate of transport was dependent upon the intracellular concentration of GSSG. The relationship between GSSG concentration and rate of transport was sigmoidal. Half-maximal transport was observed at a GSSG concentration of approximately 9.6mM. The maximal velocity was estimated to be in the range of 0.27 umole GSSG per ml of ghosts per hr. These data suggest that the rate of GSSG transport a physiologic concentrations of GSSG is not sufficiently rapid to account for the turnover of glutathione by red cells. It seems more likely that the GSSG transport system serves an emergency function of erythrocytes.

scholarly journals Active transport of GSSG from reconstituted erythrocyte ghosts

Blood ◽  
1975 ◽  
Vol 46 (1) ◽  
pp. 111-117
Author(s):  
J Prchal ◽  
SK Srivastava ◽  
E Beutler
Keyword(s):  
Active Transport ◽  
Transport System ◽  
Concentration Gradient ◽  
Human Erythrocyte ◽  
Red Cells ◽  
Intracellular Concentration ◽  
Maximal Velocity ◽  
Erythrocyte Ghosts ◽  
The Relationship

Human erythrocyte ghosts were loaded with 35S-labeled GSSG and with a sucrose marker, and the transport of GSSG to the suspending medium was studied. GSSG transport from ghosts occurred only when ATP was also present in the ghosts, proceeded against a concentration gradient, and was inhibited by fluoride. The rate of transport was dependent upon the intracellular concentration of GSSG. The relationship between GSSG concentration and rate of transport was sigmoidal. Half-maximal transport was observed at a GSSG concentration of approximately 9.6mM. The maximal velocity was estimated to be in the range of 0.27 umole GSSG per ml of ghosts per hr. These data suggest that the rate of GSSG transport a physiologic concentrations of GSSG is not sufficiently rapid to account for the turnover of glutathione by red cells. It seems more likely that the GSSG transport system serves an emergency function of erythrocytes.

The Use of the Human Erythrocyte as a Model for Studying the Action of Diuretics on Sodium and Chloride Transport

1978 ◽  
Vol 54 (6) ◽  
pp. 679-683 ◽  
Author(s):  
B. A. Brooks ◽  
A. F. Lant
Keyword(s):  
Transport System ◽  
Human Erythrocyte ◽  
Chloride Transport ◽  
Transport Systems ◽  
Na Transport ◽  
Cl Transport ◽  
Henle's Loop ◽  
Low Concentrations ◽  
Biochemical Action ◽  
Chemical Analogue

1. The Na+ and Cl− transport systems of human erythrocytes have been compared for their sensitivities to diuretics known to act in the ascending limb of Henle's loop. In addition, chemical analogues of ‘loop’ compounds and also diuretics which act in other areas of the nephron have been examined. 2. The Na+ transport system lacks specificity with respect to inhibition by ‘loop’ diuretics and also a related chemical analogue studied at equivalent concentrations. 3. The Cl− transport system is inhibited, at low concentrations, by diuretics known to act in the ascending limb of Henle's loop. 4. Erythrocyte Cl− transport offers a useful model with which to study the biochemical action of diuretics.

scholarly journals Evidence for two asymmetric conformational states in the human erythrocyte sugar-transport system

1975 ◽  
Vol 145 (3) ◽  
pp. 417-429 ◽  
Author(s):  
J E Barnett ◽  
G D Holman ◽  
R A Chalkley ◽  
K A Munday
Keyword(s):  
Glucose Transport ◽  
Transport System ◽  
Human Erythrocyte ◽  
Partition Coefficients ◽  
External Medium ◽  
Sugar Transport ◽  
Conformational States ◽  
Glucose Transport System ◽  
Oil Water

6-O-methyl-, 6-O-propyl-, 6-O-pentyl- and 6-O-benzyl-D-galactose, and 6-O-methyl-, 6-O-propyl- and 6-O-pentyl-D-glucose inhibit the glucose-transport system of the human erythrocyte when added to the external medium. Penetration of 6-O-methyl-D-galactose is inhibited by D-glucose, suggesting that it is transported by the glucose-transport system, but the longer-chain 6-O-alkyl-D-galactoses penetrate by a slower D-glucose-insensitive route at rates proportional to their olive oil/water partition coefficients. 6-O-n-Propyl-D-glucose and 6-O-n-propyl-D-galactose do not significantly inhibit L-sorbose entry or D-glucose exit when present only on the inside of the cells whereas propyl-beta-D-glucopyranoside, which also penetrates the membrane slowly by a glucose-insensitive route, only inhibits L-sorbose entry or D-glucose exit when present inside the cells, and not when on the outside. The 6-O-alkyl-D-galactoses, like the other nontransported C-4 and C-6 derivatives, maltose and 4,6-O-ethylidene-D-glucose, protect against fluorodinitrobenzene inactivation, whereas propyl beta-D-glucopyranoside stimulates the inactivation. Of the transported sugars tested, those modified at C-1, C-2 and C-3 enhance fluorodinitrobenzene inactivation, where those modified at C-4 and C-6 do not, but are inert or protect against inactivation. An asymmetric mechanism is proposed with two conformational states in which the sugar binds to the transport system so that C-4 and C-6 are in contact with the solvent on the outside and C-1 is in contact with the solvent on the inside of the cell. It is suggested that fluorodinitrobenzene reacts with the form of the transport system that binds sugars at the inner side of the membrane. An Appendix describes the theoretical basis of the experimental methods used for the determination of kinetic constants for non-permeating inhibitors.

Sign in / Sign up

Export Citation Format

Share Document