TWO DIMENSIONAL RESOLUTION OF 32P-SPECTRIN OF HUMAN ERYTHROCYTE MEMBRANES. DEPHOSPHORYLATION REACTION BY A MEMBRANE PHOSPHO PROTEIN-PHOSPHATASE

1979 ◽  
pp. 225-233
Author(s):  
Maria Tortolero ◽  
Sigmund Fischer ◽  
Jean-Pierre Piau ◽  
Jean Delaunay ◽  
Georges Schapira
Keyword(s):  
Human Erythrocyte ◽  
Protein Phosphatase ◽  
Erythrocyte Membranes ◽  
Two Dimensional ◽  
Human Erythrocyte Membranes

Human erythrocyte membrane proteins of zone 4.5 exist as families of related proteins

1985 ◽  
Vol 248 (1) ◽  
pp. C70-C79 ◽  
Author(s):  
C. F. Whitfield ◽  
D. B. Coleman ◽  
M. M. Kay ◽  
K. A. Shiffer ◽  
J. Miller ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Human Erythrocyte ◽  
Peptide Mapping ◽  
Protein Composition ◽  
Cross Reactivity ◽  
Erythrocyte Membranes ◽  
Two Dimensional ◽  
Coomassie Blue ◽  
Human Erythrocyte Membranes ◽  
Mapping Techniques

An analysis of the polypeptide composition of zone 4.5 of human erythrocyte membranes has been done by immunoautoradiographic and two-dimensional peptide mapping techniques. Results of these studies demonstrated that the Coomassie blue profile was constant, with 14 well-resolved bands present. Zone 4.5 polypeptides existed as at least four families of two or more components with closely related polypeptide backbones. The families could be distinguished on the basis of their extraction characteristics, immunological cross-reactivity, and two-dimensional peptide maps. One family was related to protein 4.1, one family was related to band 3, and two families were independent and not similar to other larger membrane proteins. The data show that all of the visualized bands in zone 4.5 do not have the same protein composition and that several closely related forms of some polypeptides are present.

scholarly journals Interaction of platelet plasma membranes with thrombin-activated platelets

Blood ◽  
1981 ◽  
Vol 57 (2) ◽  
pp. 305-312 ◽  
Author(s):  
HR Prasanna ◽  
HH Edwards ◽  
DR Phillips
Keyword(s):  
Human Erythrocyte ◽  
Plasma Membranes ◽  
Membrane Binding ◽  
Human Platelets ◽  
Platelet Membrane ◽  
Erythrocyte Membranes ◽  
Functional Sites ◽  
Activated Platelets ◽  
Platelet Membranes ◽  
Human Erythrocyte Membranes

Abstract This study described the binding of platelet plasma membranes to either control or thrombin-activated platelets. Glycoproteins in plasma membranes isolated from human platelets were labeled by oxidation with periodate followed by reduction with [3H]NaBH4. Labeled membranes were incubated with either control or thrombin-activated platelets. The amount of membranes bound was measured by separating platelets with bound membranes from solution by rapid centrifugation through 27% sucrose and determining the amount of radioactivity associated with platelets. Five- to sevenfold more membranes bound to thrombin- activated platelets than to control platelets. This enhanced binding of labeled membranes was completely inhibited by an excess of unlabeled platelet membranes. Human erythrocyte membranes had little affinity for either washed or thrombin-activated platelets and therefore did not compete for platelet-membrane binding. Binding of platelet membranes to thrombin-treated platelets was inhibited by prior incubation of the platelets with PGI2 suggesting that the enhanced binding of membranes was to activated platelets. This study demonstrates that the purified platelet membranes have functional sites that can mediate membrane binding to platelets and that quantitation of membrane binding appears to reflect the increased aggregation capability of activated platelets.

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