scholarly journals Localization of calcium in red blood cells.

1983 ◽  
Vol 31 (9) ◽  
pp. 1109-1116 ◽  
Author(s):  
M Borgers ◽  
F J Thone ◽  
B J Xhonneux ◽  
F F De Clerck

The distribution of calcium is demonstrated in human red blood cells (RBC) with a combined phosphate-pyroantimonate technique (PPA). Freshly collected blood and tissue biopsies were initially fixed in potassium phosphate-glutaraldehyde and the complexed calcium was subsequently visualized on Vibratome sections with potassium pyroantimonate. The majority of cells, both in isolated as well as "in situ" preparations, show a fine granular precipitate located at the inner leaflet of the plasma membrane. A minority of cells lack these membrane-associated deposits, exhibiting instead a random distribution of very fine precipitate in their cytoplasm. Capillary endothelial cells and pericytes are devoid of plasma membrane-bound precipitate. When irreversible crenation of RBC is induced by exposure to ionophore A 23187 and calcium, the sphero-echinocytes loose their membrane-bound precipitate, whereas the cells that retain their discocyte shape demonstrate the usual pattern of membrane-bound deposits. Contrarily, cells showing reversible shape changes induced by either A 23187-Ca2+ challenge, by adenosine triphosphate depletion during aging, or contact with lysolecithin, retain or regain the membrane-bound calcium. This cytochemical demonstrable calcium at the inner leaflet of the plasma membrane is probably bound to acidic phospholipids, since it is readily extractable with the nonionic detergent Triton X-100.

1995 ◽  
Vol 306 (3) ◽  
pp. 793-799 ◽  
Author(s):  
H Fyrst ◽  
J Knudsen ◽  
M A Schott ◽  
B H Lubin ◽  
F A Kuypers

Acyl-CoA-binding protein (ACBP) has been identified in a number of tissues and shown to affect the intracellular distribution and utilization of acyl-CoA. We have detected ACBP in the cytosol but not the membrane of human red blood cells and, using an e.l.i.s.a. with antibodies prepared against human liver ACBP, found that its concentration was 0.5 microM. To investigate the role of ACBP in human red blood cells, we added purified human liver ACBP and radiolabelled acyl-CoA to isolated membranes from these cells. ACBP prevented high concentrations of acyl-CoA from binding to the membrane but could not keep the acyl-CoA in the aqueous phase at low concentrations. This suggested the presence of a pool in the membrane with a binding affinity for acyl-CoA that was greater than that of ACBP for acyl-CoA. In the presence of lysophospholipid, this membrane-bound pool of acyl-CoA was rapidly used as a substrate by acyl-CoA:lysophospholipid acyltransferase (LAT) to generate phospholipid from lysophospholipid. We also found that ACBP-bound acyl-CoA was preferred over free acyl-CoA as a substrate by LAT. These results are the first documentation that human red blood cells contain ACBP and that this protein can affect the utilization of acyl-CoA in plasma membranes of these cells. The interactions between acyl-CoA, ACBP and the membrane suggest that there are several pools of acyl-CoA in the human red blood cell and that ACBP may have a role in regulating their distribution and fate.


Blood ◽  
1981 ◽  
Vol 58 (2) ◽  
pp. 341-349
Author(s):  
EM Alderman ◽  
HH Fudenberg ◽  
RE Lovins

Autologous membrane-bound IgG was isolated from a subpopulation of human red blood cells (RBC) with specific density greater than 1.110, by affinity chromatography of purified RBC membrane glycoprotein preparations using immobilized wheat germ agglutinin and immobilized anti-human immunoglobulin (Ig) as immunoabsorbents. The Ig-containing population thus obtained, when further separated by chromatography on Sephadex G-200 in the presence of chaotropic agents, yielded four peaks (Ia, Ib, II, and III). Double immunodiffusion revealed the presence of Ig in the first three peaks (IgM in peak Ia, IgA in Ib, and IgG in II) but not in peak III. Peak III was precipitated by the Ig-containing peaks (Ia, Ib, and II) in immunodiffusion assays, suggesting that the antigenic membrane determinants responsible for the binding of autologous Ig to senescent human RBC were contained in this peak (III). Peaks Ia, Ib and II precipitate purified asialoglycophorin; peak III was reactive with purified autoantibodies directed against asialoglycophorin. These results suggest that an age-related antigenic determinant(s) present on senescent human RBC is exposed by desialylation of the major sialoglycoprotein component of the RBC membrane.


PLoS ONE ◽  
2017 ◽  
Vol 12 (9) ◽  
pp. e0184109 ◽  
Author(s):  
Giuseppe Maulucci ◽  
Ermanno Cordelli ◽  
Alessandro Rizzi ◽  
Francesca De Leva ◽  
Massimiliano Papi ◽  
...  

Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3339-3345 ◽  
Author(s):  
AH Chishti ◽  
GJ Maalouf ◽  
S Marfatia ◽  
J Palek ◽  
W Wang ◽  
...  

The composition of the erythrocyte plasma membrane is extensively modified during the intracellular growth of the malaria parasite Plasmodium falciparum. It has been previously shown that an 80-kD phosphoprotein is associated with the plasma membrane of human red blood cells (RBCs) infected with trophozoite/schizont stage malaria parasites. However, the identity of this 80-kD phosphoprotein is controversial. One line of evidence suggests that this protein is a phosphorylated form of RBC protein 4.1 and that it forms a tight complex with the mature parasite-infected erythrocyte surface antigen. In contrast, evidence from another group indicates that the 80-kD protein is derived from the intracellular malaria parasite. To resolve whether the 80-kD protein is indeed RBC protein 4.1, we made use of RBCs obtained from a patient with homozygous 4.1(-) negative hereditary elliptocytosis. RBCs from this patient are completely devoid of protein 4.1. We report here that this lack of protein 4.1 is correlated with the absence of phosphorylation of the 80-kD protein in parasite- infected RBCs, a finding that provides conclusive evidence that the 80- kD phosphoprotein is indeed protein 4.1. In addition, we also identify and partially characterize a casein kinase that phosphorylates protein 4.1 in P falciparum-infected human RBCs. Based on these results, we suggest that the maturation of malaria parasites in human RBCs is accompanied by the phosphorylation of protein 4.1. This phosphorylation of RBC protein 4.1 may provide a mechanism by which the intracellular malaria parasite alters the mechanical properties of the host plasma membrane and modulates parasite growth and survival in vivo.


Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3339-3345 ◽  
Author(s):  
AH Chishti ◽  
GJ Maalouf ◽  
S Marfatia ◽  
J Palek ◽  
W Wang ◽  
...  

Abstract The composition of the erythrocyte plasma membrane is extensively modified during the intracellular growth of the malaria parasite Plasmodium falciparum. It has been previously shown that an 80-kD phosphoprotein is associated with the plasma membrane of human red blood cells (RBCs) infected with trophozoite/schizont stage malaria parasites. However, the identity of this 80-kD phosphoprotein is controversial. One line of evidence suggests that this protein is a phosphorylated form of RBC protein 4.1 and that it forms a tight complex with the mature parasite-infected erythrocyte surface antigen. In contrast, evidence from another group indicates that the 80-kD protein is derived from the intracellular malaria parasite. To resolve whether the 80-kD protein is indeed RBC protein 4.1, we made use of RBCs obtained from a patient with homozygous 4.1(-) negative hereditary elliptocytosis. RBCs from this patient are completely devoid of protein 4.1. We report here that this lack of protein 4.1 is correlated with the absence of phosphorylation of the 80-kD protein in parasite- infected RBCs, a finding that provides conclusive evidence that the 80- kD phosphoprotein is indeed protein 4.1. In addition, we also identify and partially characterize a casein kinase that phosphorylates protein 4.1 in P falciparum-infected human RBCs. Based on these results, we suggest that the maturation of malaria parasites in human RBCs is accompanied by the phosphorylation of protein 4.1. This phosphorylation of RBC protein 4.1 may provide a mechanism by which the intracellular malaria parasite alters the mechanical properties of the host plasma membrane and modulates parasite growth and survival in vivo.


1990 ◽  
Vol 271 (1) ◽  
pp. 133-137 ◽  
Author(s):  
H Lochs ◽  
E L Morse ◽  
S A Adibi

A function of the abundant cytoplasmic peptidases in red blood cells could be hydrolysis of oligopeptides circulating in plasma. To investigate whether human red blood cells actively transport dipeptides for this purpose, these cells were incubated with 14C-labelled glycylproline, glycylsarcosine, glycine, proline and alanine. There was uptake of each dipeptide, as indicated by their recovery as dipeptides in the cell cytoplasm. However, after a brief time (1-2 min) uptake of dipeptides abruptly ceased, while that of amino acids continued. As a result, after 30 min red blood cell uptake of amino acids was 5-13-fold greater than that of any dipeptide. Investigation of intracellular contents after 1 min of incubation revealed different metabolism for different dipeptides. The composition of intracellular radioactivity was 19-71% as intact dipeptides, 0-20% as free amino acids and 8-77% as neither dipeptides nor constituent amino acids. Investigation of the mechanism of dipeptide uptake by red blood cells showed: (1) a lack of hydrolysis by the plasma membrane, (2) no non-specific binding to the plasma membrane, and (3) a lack of saturation over a wide range of concentrations (0.05-50 mM). The data suggest that the mechanism of uptake of trace amounts of dipeptides by human red blood cells is either by simple diffusion or by a carrier system which has a very weak affinity for dipeptides. Upon entry, depending on the molecular structure, dipeptides are either hydrolysed or transformed into new compounds. The red blood cell uptake, however, does not appear to play any appreciable role in clearance of dipeptides from the plasma in the human.


Blood ◽  
1981 ◽  
Vol 58 (2) ◽  
pp. 341-349 ◽  
Author(s):  
EM Alderman ◽  
HH Fudenberg ◽  
RE Lovins

Abstract Autologous membrane-bound IgG was isolated from a subpopulation of human red blood cells (RBC) with specific density greater than 1.110, by affinity chromatography of purified RBC membrane glycoprotein preparations using immobilized wheat germ agglutinin and immobilized anti-human immunoglobulin (Ig) as immunoabsorbents. The Ig-containing population thus obtained, when further separated by chromatography on Sephadex G-200 in the presence of chaotropic agents, yielded four peaks (Ia, Ib, II, and III). Double immunodiffusion revealed the presence of Ig in the first three peaks (IgM in peak Ia, IgA in Ib, and IgG in II) but not in peak III. Peak III was precipitated by the Ig-containing peaks (Ia, Ib, and II) in immunodiffusion assays, suggesting that the antigenic membrane determinants responsible for the binding of autologous Ig to senescent human RBC were contained in this peak (III). Peaks Ia, Ib and II precipitate purified asialoglycophorin; peak III was reactive with purified autoantibodies directed against asialoglycophorin. These results suggest that an age-related antigenic determinant(s) present on senescent human RBC is exposed by desialylation of the major sialoglycoprotein component of the RBC membrane.


Blood ◽  
2003 ◽  
Vol 102 (12) ◽  
pp. 4206-4213 ◽  
Author(s):  
Virgilio L. Lew ◽  
Nuala Daw ◽  
Deisy Perdomo ◽  
Zipora Etzion ◽  
Robert M. Bookchin ◽  
...  

Abstract The plasma membrane calcium pump (PMCA) is the only active Ca2+ transporter in human red blood cells (RBCs). Previous measurements of maximal Ca2+ extrusion rates (Vmax) reported only mean values in the RBC population. Despite early evidence for differences in Ca2+ extrusion capacity among RBCs, the precise Vmax distribution remained unknown. It was important to characterize this distribution to assess the range and modality (uni- or multimodal) of PMCA Vmax variation and the likelihood of RBCs with elevated [Ca2+]i in the circulation participating in physiologic and pathologic processes. We report here the application of a new method to investigate the detailed distribution of PMCA Vmax activity in RBCs. The migrating profile of osmotic lysis curves was used to identify and quantify the fraction of cells that extrude a uniform Ca2+ load at different rates. The results revealed that RBCs from single donors have large variations in PMCA activity that follow a unimodal, broad distribution pattern consistently skewed toward higher Vmax values, suggesting an excess of cells with Vmax higher than the mean value. The method applied may provide a way of evaluating whether the observed variation in PMCA Vmax is related to cell age. (Blood. 2003;102:4206-4213)


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