ABSTRACT
Objective: To determine whether curcumin is a natural ligand for human peroxisome proliferators-activated receptors γ1 (hPPARγ1) by measuring the combination ability and internal activity. Methods: The combination ability was determined by radioactively labeled ligand binding experiment (RBCA), and the internal activity was estimated by trans-activation reporter gene test. Results: The combination ability of curcumin on hPPARγ1 showed that IC50 was (8.82 ± 0.74) μmol/L, and Ki was 0.72 μmol/L. The internal activity showed that EC50 was 7.3 μmol/L and Emax was 43.3. Conclusion: Curcumin has affinity and intrinsic activity with hPPARγ1, which suggests that curcumin may be a natural ligand of hPPARγ1.
ABSTRACT
Aim To apply sodium channels isolated and purified from rat brain and rat skelatal muscle sarcolemma to the study conotoxin.Methods Crude isolations of sodium channels were purified by 3 kinds of chromatography.The interaction between the sodium channels and conus betulinus was studied by the ligand binding experiment.Result The sequential chromatography resulted in 370-fold purification from rat brain and 2436-fold purification from rat skeletal muscle.Average specific binding active sites of purified sodium channels increased to 321 nmol?g-1 for rat brain and 268 nmol?g-1 for rat skeletal muscle respectively;Studying the interaction between venom from conus betulinus and the purified sodium channels indicated the fraction Ⅴ8 showed the highest affinity for the binding sites of the purified sodium channels.Conclusion Rat brain sodium channel and rat skeletal muscle sodium channel were purified to high purity;the fraction Ⅴ8 has the similar effect to that of the traditional ?-conotoxin.