Abstract:
The membranes from normal and Plasmodium knowlesi-infected rhemsus monkey erythrocytes (90 to 95 percent infected with early ring stage) were analyzed
for transbilayer distribution of phosphatidylcholine (PC). hosphatidylethanolamine (PE). and hosphatidylserine (PS). by means of chemical and enzymatic probes. The
external monolayer of the normal red cell membrane contained at least 68 to 72
percent of the total phosphatidylcholine and 15 to 20 percent of the total phosphati
dylethanolamine. In the infected cell, the transmembrane phosphatidylcholine
distribution appeared to be reversed, with only 20 to 30 percent of it being externally
localized, whereas roughly equal amounts of phosphatidylethanolamine were present
in the outer and'inner surfaces. However, total pho.~phatid)'lserine in both the
infected and normal red cells was exc/usi~'ely internal. Unlike that in the normal
intact cell, external phosphatidylethanolamine in the parasitized cell was readily
accessible to phospholipase A2. These results indicate that significant changes in
molecular architecture of the host cell membrane are the result of varasitization.
