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

Nomenclature of Proteins of Cow's Milk: Fifth Revision

The arrangement of lipids and some proteins in the erythrocyte membrane has been discussed. The conclusions from this are listed here as a set of general guidelines for the structure of membranes of higher organisms: some of these rules may be wrong. But at this stage it seems useful to sharpen our thoughts in this way and thereby focus attention on various specific points. 1) The basis of a membrane is a lipid bilayer with (i) choline phospholipids and glycolipids in the external half and (ii) amino (and possibly some choline) phospholipids in the cytoplasmic half. There is effectively no lipid exchange across the bilayer (unless enzymatically catalyzed) (68). 2) Some proteins extend across the bilayer. Where this is so, they will in general have carbohydrate on their surface remote from the cytoplasm. This carbohydrate may prevent the protein diffusing out of the membrane into the cytoplasm; it acts as a lock on the protein. 3) Just as lipids do not flip-flop, proteins do not rotate across the membrane. Lateral motion or rotation of lipids and proteins in the plane of the bilayer may be expected. 4) Most membrane protein is associated with the inner, cytoplasmic, urface of the membrane. Proteins are not usually associated exclusively with the outer half of the lipid bilayer. 5) Membrane proteins are a special class of cytoplasmic proteins, not of secreted proteins.

Membrane Structure: Some General Principles

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

David Kobylka

Papers

Proteins and glycoproteins of the erythrocyte membrane.

Proteins and glycoproteins of the milk fat globule membrane

Surface proteins of erythrocyte membranes.

Proteolytic digestion of proteins of the milk fat globule membrane.

Chemical modification of erythrocyte membranes: double labeling with acetic anhydride.