Species specificity in mouse glycophorin (original) (raw)

1991, Biochemical and Biophysical Research Communications

89, 65, 46 and 29 Kd mouse glycophorin proteins identified during polyacrylamide gel electrophoresis of mouse erythrocytes have been further characterized. These proteins (1) sta.ilagd positive with Periodic Acid Schiff reagent after sodium hydroxide treatment; (2) labeled using [lz3I] in intact cells; (3) co-isolated along with integral membrane proteins in the pellet fraction of sodium hydroxide treated ghosts; and (4) demonstrated a molecular weight downshift after neuraminidase treatment during electrophoresis. We have called them mouse Sialoglycoproteins 1,2,3 and 4. Immuno-blot analysis revealed distinct species specificity between human and mouse erythrocyte ghosts, and some cross-reactivity between rat and mouse erythrocyte ghosts. ® 1991 Academic Press, Inc. Glycophorin represents the major family of sialoglycoproteins (SGP) on the surface of mature human red blood cells and has been studied extensively as a model for transmembrane glycoproteins (1 for review). Glycophorin has been shown to be present on the surface of mature erythrocytes of several species (2,3,4,5,6,7,8,9,10). Both Hudson et al. (11) and Hamada (personal communication, Showa University, Japan) have made comparisons of the composition of red cell membrane glycoproteins from these species and have found significant differences in their amino acid and carbohydrate composition. This report demonstrates the presence of four distinct major murine sialoglycoproteins whose antisera demonstrates species specificity between human and murine glycophorin. While the function of glycophorin in normal red blood cells has not yet been specifically delineated, glycophorin is believed to play a role in the recognition and/or invasion of erythrocytes by malarial parasites and other microorganisms (1,12,13,14). Characterization of murine glycophorin may be used in the formation of a model mammalian system for the study of hostparasite interaction. MATERIALS AND METHODS Red cell ghost preparation and treatment. RBC ghost for all experiments conducted were prepared from packed RBC of fre]l~lcv collected and washed heparinized blood (30 units heparin/ml). Packed cells were labeled with [ ~aI] using lactoperoxidase/glucose oxidase (a modification of the Hubbard and Cohn (15) procedure), or hemolyzed unlabeled in phosphate buffer (16), The yield was approximately 3.5 ug protein/ul of ghost. Whole packed red cells were treated with 1.1 unit/ml of neuraminidase (N'ase) at 37°C for 10 and 90 minutes, with and without subsequent treatment of the ghost preparation with 0.1N NaOH, where indicated.