[Stone formation and amino acid analysis of glycoproteins of gallstones].

On the basis of amino-acid analysis of glycoprotein extracts from human pigment and cholesterol stones, we came to the conclusion that it was not collagen, reticulin, nor elastin or fibroprotein but most likely to be the precursor of collagenic polypeptide. It was postulated that in acid circumstances the precipitated collagenic polypeptide with positive charges on its surface acts as nucleus of stone to combine with negative charged acid polysaccharide, the glycoprotein thus formed further combines with negative charged pigment and/or cholesterol into crystals in the process of stone formation.