Table 1. Effects of different inhibitors on internalization of proteins via endocytosis-like mechanisms.
Uptake parameter | Direct penetration |
Receptor-mediated endocytosis | Macro- pinocytosis |
Inhibitor | Final conc. | Effect on rS3-PA uptake* |
---|---|---|---|---|---|---|
Temperature |
- |
+ |
+ |
4°C |
|
No |
Energy |
- |
+ |
- |
Sodium azide |
0.1% |
No |
Interaction with the cell membrane |
+ |
- |
+ |
Soluble heparan sulfates |
50 µg/ml |
Yes |
Caveolin-mediated uptake |
- |
- |
- |
Nystatin |
25 µg/ml |
No |
Clathrin-mediated uptake |
- |
+ |
- |
Brefeldin A |
10 µM |
No |
Actin polymerization |
- |
- |
+ |
Cytochalasin D |
5 µM |
No |
Endosomal release | - | + | + | Chloroquine (enhancer) | 50, 100 µM | No |
Determined by protein gel blotting.