Table 2.
Summary of the effect of detergents, lipids, or detergent-mixed micelles on solubility of moesin and association of moesin with F-actin in the co-sedimentation assay
| Lipids | Concentration tested (%, wt/vol) | np-Moesin/p-moesin in pellet (%)a | np-Moesin/p-moesin in pellet with F-actin (%) |
|---|---|---|---|
| None | 60 /62 | (55 /62) | |
| Triton X-100 | 0.1 | 2 /2 | (3 /4) |
| Triton X-100 + PI | 0.1 /0.01 | 3 /3 | (4 /5) |
| Triton X-100 + PI(4)P | 0.1 /0.01 | 3 /4 | (5 /47)*b |
| Triton X-100 + PI(4,5)P2 | 0.1 /0.01 | 5 /8 | (7 /45)*b |
| LysoPC | 0.01 | 0 /0 | (3 /4) |
| LysoPC + PI | 0.01 /0.01 | 2 /3 | (5 /4) |
| LysoPC + PI(4,5)P2 | 0.01 /0.01 | 5 /5 | (7 /22)**b |
Phosphorylated (p-) or non-phosphorylated (np-) moesin isolated from platelets was incubated with detergents or detergent-mixed micelles in the presence or absence of actin filaments for 1 h at 37°C before centrifugation. Proteins in supernatants and pellets were quantitated after SDS-PAGE and Coomassie brilliant blue staining by scanning densitometry. Percent indicates the amount of moesin in pellet fraction. F-actin was stable in all conditions.
Data are presented as mean (n = 3) and each SD was <10% of the mean.
Significant difference between np-moesin and p-moesin by t test (* p < 0.001; ** p < 0.01).