The elucidation of the molecular architecture of cell membranes is a central goal for cell biology, as structure lies at the heart of function. The erythrocyte plasma membrane has long provided a favored testing ground for this inquiry. Human red blood cells are readily available, relatively homogeneous, and relevant to medicine. Their plasma membranes can be easily isolated intact and essentially free of contamination from other cells, organelles, and cytoplasmic contents. This membrane is complex enough to be interesting and, to some degree, representative, yet it is simple enough to be analyzed as a whole. These circumstances make it likely that the human red cell plasma membrane will be the first whose molecular anatomy is known in any degree of satisfying detail. The literature concerning the proteins of erythrocyte membranes and membranes in general has been the subject of repeated review (1 9). This article will focus on the localization and modes of association of individual major polypeptides within the human red cell membrane.

https://rupress.org/jcb/article-pdf/62/1/1/1386885/1.pdf

THE ORGANIZATION OF PROTEINS IN THE HUMAN RED BLOOD CELL MEMBRANE A Review

Transmembrane control of the receptors on normal and tumor cells: I. Cytoplasmic influence over cell surface components☆

Membrane Asymmetry: The nature of membrane asymmetry provides clues to the puzzle of how membranes are assembled.

The anion transport system of the red blood cell. The role of membrane protein evaluated by the use of 'probes'.

The size and detergent binding of membrane proteins.

(3H)DIDS (4,4′-diisothiocyano-2,2′-ditritiostilbene-disulfonate) was used as a convalent label for membrane sites involved in anion permeability. The label binds to a small, superficially located population of sites, about 300,000 per cell, resulting in almost complete inhibition of anion exchange. The relationship of biding to inhibition is linear suggesting that binding renders each site nonfunctional. In the inhibitory range less than 1% of the label is associated with lipids but at higher concentrations of DIDS, the fraction may be as high as 4%. In ghosts, however, treatment with (3H)DIDS results in extensive labeling of lipids. In cells, a protein fraction that behavens on SDS acrylamide gels as thought its molecular weight is 95,000 daltons (95K) is predominatly labeled by (3H)DIDS. The only other labeled protein is the major sialoglycoprotein which contains less than, 5% of the total bound (3H)DIDS. Because of the linear relationship of binding to inhibition and the unique architecture of the site, it is suggested that the (3H)DIDS-binding site of the 95K protein is the substrate binding site of the anion transport system. The 95K protein is asymmetrically arranged in the membrane with the sites arranged on the outer face accessible to agent in the medium. In “leaky” ghost, only a few additional binding sites can be reached from the inside of the membrane in the 95K protein, in contrast to the extensive labeling of other membrane proteins in ghosts as compared to cells.

Membrane proteins related to anion permeability of human red blood cells. I. Localization of disulfonic stilbene binding sites in proteins involved in permeation.

Z. I. Cabantchik

Papers

Membrane proteins related to anion permeability of human red blood cells. I. Localization of disulfonic stilbene binding sites in proteins involved in permeation.