The Binding Capacity of Human Albumin for Bilirubin and Its Significance in the Pathogenesis of Kernicterus

Abstract

The binding capacity of human albumin for bilirubin was studied by spectrophotometry and Sephadex G-25 gel filtration. It was found that one molecule of albumin could bind tightly only one molecule of bilirubin. While in contrast to earlier investigations, this corresponds well with clinical experience of development of kernicterus in newborns. Differences in the absorbance pattern at pH 7.4 and 8.3 are explained by a second molecule of bilirubin being able to form a dimer on the molecule already bound. This second molecule of bilirubin dissociates freely and is partly retained on a Sephadex column.

Key Words:

• Albumin
• bilirubin
• kernicterus
• Sephadex
• spectrophotometry