Bovine brain Goα was specifically palmitoylated in vitro. The apparent dissociation constant for depalmitoylated Goα (dGoα) was 0.273 μM, while that for palmitoylated Goα (pGoα) was 5.77 nM. The dissociation rate constant (K21) and dissociation half-life for dGoα were 8.4 × 10-4 min and 825 min respectively, while no significant dissociation of pGoα was detected. The limiting membrane insertion pressures for pGoα and dGoα were 44.4 mN/m and 41.3 mN/m respectively. These data suggested that palmitoylation facilitated the membrane association of Goα. Conformational changes of dGoα and pGoα detected by monitoring fluorescence spectra and fluorescence quenching were significantly different after they were associated with the membrane. It was suggested that conformational changes of Goα upon membrane association might be related to regulation of Goα signaling by palmitoylation.
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology
- Cell Biology