Carcinoembryonic antigen-related cell adhesion molecule 1 is the 85-kilodalton pronase-resistant biliary glycoprotein in the cholesterol crystallization promoting low density protein-lipid complex

• Published in: Hepatology (Baltimore, Md.) Vol. 34; no. 6; pp. 1075 - 1082
• Main Authors: Jirsa, Milan, Muchov[aacute], Lucie, Dr[aacute]berov[aacute], Lubica, Dr[aacute]ber, Petr, [Scaron]m[iacute]d, Franti[scaron]ek, Kuroki, Masahide, Mare[ccaron]ek, Zden[ccaron]k, Groen, Albert K.
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Elsevier Inc 01.12.2001; W.B. Saunders; Wiley
• Subjects: Adenosine Triphosphatases - chemistry; Adenosine Triphosphatases - isolation & purification; Adenosine Triphosphatases - metabolism; Adenosine Triphosphatases - physiology; Analytical, structural and metabolic biochemistry; Antigens, CD; Bile - metabolism; Biological and medical sciences; Cell Adhesion Molecules - chemistry; Cell Adhesion Molecules - isolation & purification; Cell Adhesion Molecules - metabolism; Cell Adhesion Molecules - physiology; Cholelithiasis - metabolism; Cholesterol - physiology; Crystallization; Drug Resistance; Fundamental and applied biological sciences. Psychology; Gallbladder - metabolism; Glycoproteins; Glycoproteins - metabolism; Humans; Lipids - physiology; Molecular Weight; Pronase - physiology; Proteins; Proteins - physiology; Reference Values; Human; Biliary tract; Carcinoembryonic antigen; Pathogenesis; Crystallization; Glycoprotein; Cell adhesion molecule; Lithiasis; Digestive diseases; Metabolic diseases; Biliary tract disease; Cholesterol
• ISSN: 0270-9139; 1527-3350
• DOI: 10.1053/jhep.2001.29372

A pronase resistant 85-kd glycoprotein in the Concanavalin A[ndash ]binding fraction (CABF) of biliary glycoproteins has been reported to act as a promotor of cholesterol crystallization. De Bruijn et al. (Gastroenterology 1996;110:1936-1944) found this protein in a low-density protein-lipid complex (LDP) with potent cholesterol crystallization promoting activity. This study identifies and characterizes this protein. An LDP was prepared from CABF by discontinuous gradient ultracentrifugation. Proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), blotting and immunochemical staining with anti-carcinoembryonic antigen, CEA-related adhesion molecule 1 (CEACAM1) cross-reacting antibodies. Biliary concentrations of CEA cross-reacting proteins were determined in patients with and without gallstones. Two isoforms of CEACAM1 (85- and 115-kd bands), CEA and 2 CEA cross-reacting protein bands of 40 and 50 kd were found in human bile. All bands were also present in CABF, but only a subfraction of the 85-kd band found in the LDP was resistant to digestion with pronase. CEACAM1-85 exhibited potent cholesterol crystallization promoting activity in vitro and accounted for most of the activity in CABF. Total CEA cross-reacting protein concentrations were the same in gallbladder biles from patients with cholesterol and pigment gallstones but only half of those in biles from nongallstone subjects. In conclusion, we have identified the protein component of the cholesterol crystallization promoting LDP to be CEACAM1-85. (HEPATOLOGY 2001;34:1075-1082.)