Table 1.
Enrichment of TR and EGFR in MVBs isolated using either anti-EGFR-gold or anti-TR-gold
| Gold | Antigen | Yield % PNS | Fold enrichment |
|---|---|---|---|
| Anti-TR | TR | 22.9 | 122.2 |
| (B3/25) | EGFR | 29.1 | 155.1 |
| Anti-EGFR | TR | 12.3 | 65.5 |
| (108) | EGFR | 30.2 | 160.1 |
MVBs were isolated by loading radiolabeled HEp-2 cells with either anti-EGFR-gold or anti-TR-gold in the presence of saturating EGF (200 ng/ml) for 90 min at 20°C. Gold-loaded MVBs were then isolated as described in MATERIALS AND METHODS. The amounts of TR and EGFR in these isolated fractions were determined by Western blotting and expressed as a percentage of the total of each loaded on the fractionation gradient (% PNS). By measuring trichloroacetic acid precipitable 35S-radioactivity in the PNS and isolated MVB fractions, it was possible to determine fold enrichment of TR and EGFR in the anti-EGFR-gold– and anti-TR-gold–isolated MVB.