Differential analysis of protein profiles of vesicular phase and micellar phase of gallbladder bile from cholesterol gallstone patients

Abstract

To identify the proteins which play key roles during the formation of cholesterol gallstone, differential analysis was carried out that the proteome of vesicular phase and micellar phase of gallbladder bile from cholesterol gallstone patients. Vesicular and micellar phases were isolated by the density gradient ultracentrifugation method. Total proteins from the two phases were extracted, and the protein expressional profiles were established by two-dimensional electrophoresis respectively. The differentially expressed protein spots analyzed by ImageMaster two-dimensional electrophoresis analysis software were identified with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The concentrations of proteins from vesicular phase and micellar phase of gallbladder bile from cholesterol gallstone patients were (1.5358 +/- 0.0682) mg/ml and (7.1222 +/- 0.2022) mg/ml (P < 0.01) respectively. The average matched protein spots were 120 +/- 24 and 198 +/- 37 in the two groups respectively. There were 72 +/- 16 matched spots in the two representative gels maps and the matched rate was 45.30%. Eight differentially expressed protein spots were identified from the two cholesterol-carrier phases. Among them, 6 were up-regulated with 2 down-regulated in vesicular phase compared with micellar phase. The abundance differentiation of RBP and HSA was confirmed by immunoblotting. The differential protein profiles of vesicular phase and micellar phase of gallbladder bile from cholesterol gallstone patients were established and 8 differential protein spots were identified successfully. The data may be a basis for further screening the key regulators of formation of cholesterol gallstone.