Biliary nonmucin glycoproteins in patients with and without gallstones

Total protein, mucin, and specific nonmucin glycoproteins are proposed pronucleating agents in cholesterol gallstone pathogenesis. However, characterization of specific nonmucin glycoproteins in patients with and without gallstones is unknown. Furthermore, nonmucin glycoproteins may be qualitatively different in patients with and without gallstones. Total protein and total and specific nonmucin glycoproteins were studied in gallbladder bile of 43 patients with cholesterol gallstones and 13 patients without gallstones. Patients with cholesterol gallstones had higher concentrations of both total protein and nonmucin glycoproteins than that observed in control patients (P < 0.05). SDS gel electrophoresis of nonmucin glycoproteins demonstrated an 84-kDa protein that was present significantly more often in patients with cholesterol gallstones (87% vs 8%, P < 0.05). Proposed 130- and 42-kDa pronucleating and 120-kDa anti-nucleating nonmucin glycoproteins were present in similar percentages in gallstone and control bile. Moreover, gallbladder bile of patients with the 84-kDa protein nucleated 50% faster than model bile and >100% faster than that of patients without this protein (P < 0.05). The currently described gallbladder pronucleating and anti-nucleating proteins are found with equal frequency in cholesterol gallstone and control patients. However, an 84-kDa protein is found more commonly in gallstone patients and was associated with a shortened crystal observation time. Thus, this glycoprotein may be important in cholesterol gallstone pathogenesis.