PMID: 429290Apr 10, 1979Paper

Bilirubin. Solubility and interaction with albumin and phospholipid

The Journal of Biological Chemistry
R Brodersen

Abstract

Bilirubin is generally considered a lipophilic substance, and its neurotoxicity is ascribed to an affinity for lipids in the central nervous system. In the present paper, it is shown that the solubility of bilirubin in apolar solvents and in triglycerides is low and increases with solvent polarity. Consequently, bilirubin should not be characterized as lipophilic. The solubility in aqueous buffers was studied under exclusion of light and was found lower than previously reported, about 7 nM at pH 7.4, temperature 37 degrees C, increasing with higher pH, approximately in inverse proportion with the squared hydrogen ion concentration. Binding of bilirubin to human serum albumin was studied by the rate of oxidation with peroxidase of the free ligand at equilibrium. The stoichiometry of proton involvement in the binding process was investigated by acidimetric titration. It is concluded that precipitation of bilirubin in vivo is thermodynamically possible. It was further demonstrated by light absorption spectroscopy that bilirubin forms a complex with phosphatidylcholine in diethyl ether and that an aqueous suspension of phosphatidylcholine enhanced aggregation of bilirubin. Transfer of bilirubin dianion from its complex with plasma ...Continue Reading

Related Concepts

Related Feeds

ASBMB Publications

The American Society for Biochemistry and Molecular Biology (ASBMB) includes the Journal of Biological Chemistry, Molecular & Cellular Proteomics, and the Journal of Lipid Research. Discover the latest research from ASBMB here.

Related Papers

Acta Chemica Scandinavica. Series B: Organic Chemistry and Biochemistry
P C Frandsen, R Brodersen
Archives of Disease in Childhood
A Knudsen, R Brodersen
Chemistry and Physics of Lipids
P WaldeP L Luisi
© 2021 Meta ULC. All rights reserved