The pronase resistance of cholesterol-nucleating glycoproteins in human bile

Gastroenterology. 1996 Jun;110(6):1926-35. doi: 10.1053/gast.1996.v110.pm8964420.


Background & aims: Many putative pronucleating proteins have been isolated from the biliary concanavalin A (con A)-binding fraction. The pronase resistance of the overall nucleating-promoting activity was almost never taken into consideration. The aim of this study was to identify the major pronase-resistant con A-binding glycoproteins.

Methods: Pronase-treated and -untreated con A-binding glycoproteins were separated on a Superose 12 gel permeation column (Pharmacia, Uppsala, Sweden) and tested in a crystal growth assay. Proteins were identified by amino-terminal sequencing.

Results: Con A-binding pronucleating activity eluted in two peaks on the Superose column. This activity was unaltered after pronase treatment. Activity peak I contained too little protein to allow amino-terminal sequencing. In activity peak II, the major pronase-resistant con A-binding glycoproteins were identified as alpha 1-antitrypsin and alpha 1-antichymotrypsin. The 130-kilodalton nucleation promoter was identified as aminopeptidase N, but the full pronase resistance of this protein, reported earlier, was not confirmed. Immunoabsorptive removal of alpha 1-antitrypsin and alpha 1-antichymotrypsin and immunopurification showed that only alpha 1-antichymotrypsin had pronucleating activity.

Conclusions: The pronase resistance of the nucleating-promoting activity of the con A-binding glycoprotein fraction was confirmed. An important part of this activity could be attributed to alpha 1-antichymotrypsin. It is an acute-phase protein, as are many other pronucleating proteins, which might indicate a general mechanism of action in gallstone formation.

MeSH terms

  • Adult
  • Aged
  • Amino Acid Sequence
  • Bile / drug effects
  • Bile / metabolism*
  • Cholesterol / physiology*
  • Chromatography, Gel
  • Concanavalin A
  • Crystallization
  • Drug Resistance
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Glycoproteins / genetics
  • Glycoproteins / physiology*
  • Humans
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Pronase / genetics
  • Pronase / pharmacology*
  • Sepharose
  • alpha 1-Antichymotrypsin / physiology
  • alpha 1-Antitrypsin / physiology


  • Glycoproteins
  • alpha 1-Antichymotrypsin
  • alpha 1-Antitrypsin
  • Concanavalin A
  • Sepharose
  • Superose 12
  • Cholesterol
  • Pronase