Band 3 mobility in camelid elliptocytes: implications for erythrocyte shape.
Measurements of time-resolved phosphorescence anisotropy were used to monitor the rotational diffusion of eosin-labeled band 3 in membranes of the elliptocytic erythrocytes of alpacas and camels. The rotational freedom of camelid band 3 was more restricted than for human band 3. Removal of the peripheral membrane proteins from human erythrocyte membranes, by high-pH treatment, increased the band 3 rotational freedom. The same high-pH treatment of alpaca and camel erythrocyte membranes failed to alter the rotational freedom of band 3 in these species and also failed to remove ankyrin. Treatment of human and alpaca erythrocyte membranes with trypsin, which removed the cytoplasmic domain of band 3, caused a marked increase in band 3 rotational freedom in both species. We suggest that ankyrin may modulate the rotational freedom of band 3 in camelid erythrocytes, thereby influences the erythrocyte shape and deformability. The rotational freedom of band 3 in sheep, pig, and rat erythrocyte membranes was also examined and found to be slightly greater than for human band 3. This is consistent with the inability of glyceraldehyde-3-phosphate dehydrogenase to bind to band 3 in the erythrocyte membranes of these species.
McPherson
R A
RA
Department of Biochemistry, La Trobe University, Bundoora, Victoria, Australia.
Sawyer
W H
WH
Tilley
L
L
D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry* / Q000302:isolation & purification; D015153:Blotting, Western; D002161:Camelids, New World / Q000097:blood*; D002162:Camelus / Q000097:blood*; D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000737:chemistry*; D004912:Erythrocytes / Q000166:cytology*; D015186:Hominidae / Q000097:blood; D006801:Humans; D008163:Luminescent Measurements; D051381:Rats / Q000097:blood; D012756:Sheep / Q000097:blood; D013552:Swine / Q000097:blood
D001457:Anion Exchange Protein 1, Erythrocyte