Related Experiment Video
Updated: Aug 21, 2026

ABCG5/G8 Crystallization in a Lipidic Bicelle Environment for X-Ray Crystallography
Published on: August 25, 2023
Cholesterol saturation rather than phospholipid/bile salt ratio or protein content affects crystallization sequences
N G Venneman1, P Portincasa, G P Vanberge-Henegouwen
1University Medical Center Utrecht, the Netherlands.
Background:
In model biles, cholesterol crystallization (an important factor in gallstone formation) mainly depends on phospholipid/bile salt ratios with characteristic sequences of plate-like (monohydrate) vs. non-plate-like (presumed anhydrous: arcs, needles, tubules, spirals) cholesterol crystals. We now investigate whether the same phenomenon occurs in human bile.
Methods:
Appearances of plate-like and non-plate-like cholesterol crystals were determined in filtered bile of 80 cholesterol gallstone patients, and related to biliary lipid and pro-nucleating protein composition.
Results:
Non-plate-like crystals appeared before plate-like crystals in 9 biles, on the same day in 24 biles, and after plate-like crystals in 31 biles. In 16 biles only plate-like crystals were observed. Crystal sequences did not depend on biliary lipid or protein composition. Cholesterol saturation indexes were higher in biles with than without non-plate-like crystals (150 +/- 6 vs. 125 +/- 12, P = 0.02). In contrast, phospholipid/(bile salt + phospholipid) ratios, bile salt species, phospholipid classes, concentrations of mucin, IgG, IgM, IgA, haptoglobin and alpha-1 acid glycoprotein did not differ.
Conclusions:
Cholesterol crystallization sequences in human bile depend on cholesterol saturation index rather than on phospholipid/bile salt ratio.
Related Concept Videos
Membrane Fluidity
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Membrane Fluidity
Bile
Bile is released when dietary fats enter...
Overview of Fatty Acid Metabolism
Fatty acids are catabolized in a process called beta-oxidation, which takes place in the matrix of the mitochondria and converts their fatty acid chains into two-carbon units of acetyl groups. The acetyl...
Blood Studies for Cardiovascular System III: Serum Lipid Profile
Serum lipids are fats and fatty substances in the blood and are crucial for various bodily functions, including energy storage, cellular structure, and hormone production. Serum lipids consist of cholesterol, triglycerides, and phospholipids.
Cholesterol is a soft, fat-like substance found in all body cells. It is crucial for producing hormones, vitamin D, and substances that aid...
Lipid Absorption
These breakdown products bind with bile salts and lecithin to form micelles, which quickly pass between microvilli to come in close contact with the apical...

