Orientation of structural polypeptides of equine infectious anemia virus

Lactoperoxidase iodination of intact and disrupted equine infectious anemia virus revealed that glycopeptide gp79 is the major surface component of this virus, whereas glycopeptides gp64 and gp40 as well as the principle nonglycosylated structural polypeptides p29 and p13 are internal. Virus 'envelope' particles, banding in isopycnic centrifugation at approximately 1.10 g/cm3, contained the glycopeptides but no internal nonglycosylated proteins. Glycopeptides gp79, gp64 and gp40 and core polypeptide p29 were isolated by SDS-PAGE, iodinated in vitro, and compared by two-dimensional tryptic peptide analysis. Tryptic digests of the glycopeptides were similar but distinct from that of p29.