Identification of sheep red blood cell (SRBC) surface immune-responsive peptides detected by antisera from SRBC-immunized rats.

Abstract

To identify the sheep red blood cell (SRBC) surface immune-responsive peptides, immuno-reactive fraction of SRBC was detected by SDS-PAGE and western blot analysis with antisera from SRBC-immunized rats. Then the most intense immuno-reactive band on SDS-PAGE was subjected to nanoLC-ESI-MS/MS analysis, and 17 proteins were identified including membrane proteins of erythrocytes such as band 3 anion transport protein isoform 1 (Anion exchange protein 1; AE-1, CD233), Ammonium transporter Rh type A (Rh type A glycoprotein, CD241) and Ankyrin-1 (ANK-1), Spectrin beta chain. Among them, plasma protein AE-1 (CD233) and Rh type A glycoprotein (CD241) have transmembrane domain and correspond to extracellular region in their sequences. These extracellular regions of the plasma membrane proteins are supposed to be major immune-responsive peptides of SRBC in rats. These peptides are promising for the construction of an ELISA system which does not require the processing of SRBC membrane ghosts.