Aim: To investigate the relationship between p57 and cholesterol in cellular membrane under physiological conditions.
Methods: Different concentrations of mbetaCD were used to extract cholesterol from cellular membrane of U937 cells. The cellular membrane was prepared by ultracentrifugation and the content change of p57 in cellular membrane component was measured by Western blot analysis. Discontinuous sucrose density gradient centrifugation was used to prepare lipid rafts and the content of p57 in them was measured by Western blot analysis.
Results: The degradation of cholesterol level in cellular membrane didn't lead to obvious content change of p57 in cellular membrane component. Furthermore, no p57 protein was found in lipid rafts.
Conclusion: No relationship between p57 and cholesterol in cellular membrane was found in the physiological condition, which is obviously different from that in pathological condition caused by the invasion of pathogenic mycobacteria.