scholarly journals Genetic variants of human red-cell membrane sialoglycoprotein β. Study of the alterations occurring in the sialoglycoprotein-β gene

1988 ◽  
Vol 250 (2) ◽  
pp. 407-414 ◽  
Author(s):  
M J Tanner ◽  
S High ◽  
P G Martin ◽  
D J Anstee ◽  
P A Judson ◽  
...  

We have studied the DNA of individuals who express an altered sialoglycoprotein beta on their red cells by using Southern blotting with sialoglycoprotein-beta cDNA probes. Individuals of the Leach phenotype do not express any beta (sialoglycoprotein beta) or gamma (sialoglycoprotein gamma) on their red cells, and we show that about 7 kb of DNA, including the 3′ end of the beta gene, is deleted in this DNA. Any protein product of this gene is likely to lack the membrane-associating domain of beta. We have also examined the DNA of two types of other individuals (Yus-type and Gerbich-type) who have red cells that lack beta and gamma, but contain abnormal sialoglycoproteins related to beta. These two types of DNA contain different internal deletions of about 6 kb in the beta gene. We suggest that these deletions result from the presence of two different sets of internal homology in the beta gene, and on this basis we propose structures for the abnormal Yus-type and Gerbich-type sialoglycoproteins which are consistent with the other evidence that is available. We provide evidence that beta and gamma are products of the same gene and suggest a possible mechanism for the origin of gamma based on leaky initiation of translation of beta mRNA.

Blood ◽  
1984 ◽  
Vol 63 (5) ◽  
pp. 1096-1101
Author(s):  
S Fujii ◽  
GL Dale ◽  
E Beutler

Glutathione (GSH) dependent protection against oxidative damage of human red cell membrane was examined. An artificial system was used in which chloroform/methanol-extracted red cell lipids, in the form of liposomes, were subjected to attack by a peroxidation system consisting of ascorbate-Fe3+. Human erythrocytes contained a nondialyzable factor, completely inactivated by heating in a boiling water bath for 3 min, which showed GSH-dependent inhibition against lipid peroxidation and was devoid of GSH peroxidase activity. On the other hand, GSH-S transferase, highly purified by affinity chromatography, had no inhibitory activity. These findings strongly indicate that the GSH- dependent protection against lipid peroxidation of human red cell membrane is mediated by one or more proteins other than GSH peroxidase and GSH-S transferase.


Blood ◽  
1984 ◽  
Vol 63 (5) ◽  
pp. 1096-1101 ◽  
Author(s):  
S Fujii ◽  
GL Dale ◽  
E Beutler

Abstract Glutathione (GSH) dependent protection against oxidative damage of human red cell membrane was examined. An artificial system was used in which chloroform/methanol-extracted red cell lipids, in the form of liposomes, were subjected to attack by a peroxidation system consisting of ascorbate-Fe3+. Human erythrocytes contained a nondialyzable factor, completely inactivated by heating in a boiling water bath for 3 min, which showed GSH-dependent inhibition against lipid peroxidation and was devoid of GSH peroxidase activity. On the other hand, GSH-S transferase, highly purified by affinity chromatography, had no inhibitory activity. These findings strongly indicate that the GSH- dependent protection against lipid peroxidation of human red cell membrane is mediated by one or more proteins other than GSH peroxidase and GSH-S transferase.


1974 ◽  
Vol 64 (6) ◽  
pp. 706-729 ◽  
Author(s):  
W. R. Redwood ◽  
E. Rall ◽  
W. Perl

The permeability coefficients of dog red cell membrane to tritiated water and to a series of[14C]amides have been deduced from bulk diffusion measurements through a "tissue" composed of packed red cells. Red cells were packed by centrifugation inside polyethylene tubing. The red cell column was pulsed at one end with radiolabeled solute and diffusion was allowed to proceed for several hours. The distribution of radioactivity along the red cell column was measured by sequential slicing and counting, and the diffusion coefficient was determined by a simple plotting technique, assuming a one-dimensional diffusional model. In order to derive the red cell membrane permeability coefficient from the bulk diffusion coefficient, the red cells were assumed to be packed in a regular manner approximating closely spaced parallelopipeds. The local steady-state diffusional flux was idealized as a one-dimensional intracellular pathway in parallel with a one-dimensional extracellular pathway with solute exchange occurring within the series pathway and between the pathways. The diffusion coefficients in the intracellular and extracellular pathways were estimated from bulk diffusion measurements through concentrated hemoglobin solutions and plasma, respectively; while the volume of the extracellular pathway was determined using radiolabeled sucrose. The membrane permeability coefficients were in satisfactory agreement with the data of Sha'afi, R. I., C. M. Gary-Bobo, and A. K. Solomon (1971. J. Gen. Physiol. 58:238) obtained by a rapid-reaction technique. The method is simple and particularly well suited for rapidly permeating solutes.


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