Uptake and binding of disaccharides in human erythrocytes

1976 ◽  
Vol 54 (1) ◽  
pp. 99-101 ◽  
Author(s):  
Ivan Beneš ◽  
Arnošt Kotyk
Keyword(s):  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Intact Cell ◽  
Binding Capacity ◽  
Human Erythrocytes ◽  
Human Erythrocyte Membrane ◽  
Maximum Binding Capacity

Disaccharides (sucrose, lactose, melibiose, cellobiose, trehalose, maltose, and isomaltose) are not transported across the human erythrocyte membrane. Maltose alone is bound in appreciable amounts to the intact cell as well as ghost membranes and competes mutually for uptake with D-glucose. In (NH4)2SO4-precipitated membrane preparations, maltose binds more strongly than other disaccharides (KD = 1.3 × 10−5 M; maximum binding capacity, 71 pmol/mg protein) and again competes mutually with D-glucose. Phloretin inhibits the binding of glucose much more than that of maltose.

scholarly journals Phosphotyrosine phosphatase associated with band 3 protein in the human erythrocyte membrane

1996 ◽  
Vol 314 (3) ◽  
pp. 881-887 ◽  
Author(s):  
Yehudit ZIPSER ◽  
Nechama S. KOSOWER
Keyword(s):  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Intact Cell ◽  
Band 3 ◽  
Band 3 Protein ◽  
Human Erythrocyte Membrane ◽  
Major Fraction ◽  
Phosphotyrosine Phosphatase ◽  
A Minor ◽  
Triton X

The anion-exchange band 3 protein is the main erythrocyte protein that is phosphorylated by tyrosine kinase. To study the regulation of band 3 phosphorylation, we examined phosphotyrosine phosphatase (PTP) activity in the human erythrocyte. We show that the human erythrocyte membrane contains a band 3-associated neutral PTP which is activated by Mg2+ and inhibited by Mn2+ and vanadate. The PTP is active in the intact cell and in the isolated membrane. A major fraction of the PTP is tightly bound to the membrane and can be extracted from it by Triton X-100; a minor part is associated with the Triton X-100-insoluble cytoskeleton. The behaviour of the PTP parallels that of band 3, the major fraction of which is extractable by detergents with a minor fraction being anchored to the cytoskeleton. Moreover, band 3 is co-precipitated when the PTP is immunoprecipitated from solubilized membranes, and PTP is co-precipitated when band 3 is immunoprecipitated. The PTP appears to be related to PTP1B (identified using an antibody to an epitope in its catalytic domain and by molecular mass). The system described here has a unique advantage for PTP research, since it allows the study of the interaction of a PTP with an endogenous physiological substrate that is present in substantial amounts in the cell membrane. The membrane-bound, band 3-associated, PTP may play a role in band 3 function in the erythrocyte and in other cells which have proteins analogous to band 3.

scholarly journals Analysis of Receptor for Vibrio choleraeEl Tor Hemolysin with a Monoclonal Antibody That Recognizes Glycophorin B of Human Erythrocyte Membrane

1999 ◽  
Vol 67 (10) ◽  
pp. 5332-5337 ◽  
Author(s):  
Dongyan Zhang ◽  
Junko Takahashi ◽  
Taiko Seno ◽  
Yoshihiko Tani ◽  
Takeshi Honda
Keyword(s):  
Monoclonal Antibody ◽  
Vibrio Cholerae ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Mammalian Cells ◽  
Biochemical Characterization ◽  
Human Erythrocytes ◽  
Human Erythrocyte Membrane ◽  
El Tor ◽  
Glycophorin B

ABSTRACT El Tor hemolysin (ETH), a pore-forming toxin secreted byVibrio cholerae O1 biotype El Tor and most Vibrio cholerae non-O1 isolates, is able to lyse erythrocytes and other mammalian cells. To study the receptor for this toxin or the related molecule(s) on erythrocyte, we first isolated a monoclonal antibody, B1, against human erythrocyte membrane, which not only blocks the binding of ETH to human erythrocyte but also inhibits the hemolytic activity of ETH. Biochemical characterization and immunoblotting revealed that this antibody recognized an epitope on the extracellular domain of glycophorin B, a sialoglycoprotein of erythrocyte membrane. Erythrocytes lacking glycophorin B but not glycophorin A were less sensitive to the toxin than were normal human erythrocytes. These results indicate that glycophorin B is a receptor for ETH or at least an associated molecule of the receptor for ETH on human erythrocytes.

scholarly journals The organization of the major protein of the human erythrocyte membrane

1974 ◽  
Vol 137 (3) ◽  
pp. 531-534 ◽  
Author(s):  
D. H. Boxer ◽  
R. E. Jenkins ◽  
M. J. A. Tanner
Keyword(s):  
Membrane Protein ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Intact Cell ◽  
The Other ◽  
Major Protein ◽  
Erythrocyte Ghosts ◽  
Human Erythrocyte Membrane ◽  
Cytoplasmic Surface ◽  
Peptide Maps

The enzyme lactoperoxidase was used to catalyse the radioiodination of membrane proteins in intact human erythrocytes and in erythrocyte ‘ghosts’. Two major proteins of the erythrocyte membrane were isolated after iodination of these two preparations, and the peptide ‘maps’ of each protein so labelled were compared. Peptides from both proteins are labelled in the intact cell. In addition, further mobile peptides derived from one of the proteins are labelled only in the ‘ghost’ preparation. Various sealed ‘ghost’ preparations were also iodinated, lactoperoxidase being present only at either the cytoplasmic or extra-cellular surface of the membrane. The peptide ‘maps’ of protein E (the major membrane protein) labelled in each case were compared. Two discrete sets of labelled peptides were consistently found. One group is obtained when lactoperoxidase is present at the extra-cellular surface and the other group is found when the enzyme is accessible only to the cytoplasmic surface of the membrane. The results support the assumption that the organization of protein E in the membrane of the intact erythrocyte is unaltered on making erythrocyte ‘ghosts’. They also confirm previous suggestions that both the sialoglycoprotein and protein E extend through the human erythrocyte membrane.

scholarly journals Facilitated transport of amino acids across organic phases and the human erythrocyte membrane

1980 ◽  
Vol 188 (2) ◽  
pp. 541-548 ◽  
Author(s):  
R C Hider ◽  
W McCormack
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Erythrocyte Membrane ◽  
Transfer Process ◽  
Human Erythrocyte ◽  
Facilitated Transport ◽  
Human Erythrocytes ◽  
Human Erythrocyte Membrane ◽  
Chloroform Phase

1. An artificial facilitated amino-acid-transfer process operating across a chloroform phase is reported. 2. This process utilizes a family of bis(salicylamidato)copper(II) complexes. 3. A mechanism is proposed for this process and for its sensitivity towards cyanide and bathophenanthroline sulphonate. 4. Facilitated transfer of L-leucine in human erythrocytes has been shown to be inhibited by bathophenanthroline sulphonate.

scholarly journals A Ceramide Pentasaccharide of Human Erythrocyte Membrane

1974 ◽  
Vol 249 (4) ◽  
pp. 1022-1025
Author(s):  
Klaus Stellner ◽  
Sen-Itiroh Hakomori
Keyword(s):  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Human Erythrocyte Membrane
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