Circular dichroism spectroscopic detection of ligand binding induced subdomain IB specific structural adjustment of human serum albumin.

TitleCircular dichroism spectroscopic detection of ligand binding induced subdomain IB specific structural adjustment of human serum albumin.
Publication TypeJournal Article
Year of Publication2013
AuthorsZsila, F
JournalJ Phys Chem B
Volume117
Issue37
Pagination10798-806
Date Published2013 Sep 19
ISSN1520-5207
KeywordsBile Acids and Salts, Binding Sites, Circular Dichroism, Dehydroepiandrosterone Sulfate, Fatty Acids, Gemfibrozil, Humans, Ibuprofen, Ligands, Protein Conformation, Protein Structure, Tertiary, Saponins, Serum Albumin, Tyrosine
Abstract

This work demonstrates for the first time that binding of various compounds within subdomain IB of human serum albumin (HSA) provokes characteristic changes in the near-UV circular dichroism (CD) spectrum of the protein. It can be inferred from the spectroscopic features of difference ellipticity signals and from CD displacement experiments that tyrosine residues located in subdomain IB are the source of the observed spectral alterations. It is proposed that inclusion of some ligand molecules (bile acids, dehydroepiandrosterone sulfate, steroidal terpenes, fatty acids, ibuprofen, and gemfibrozil) into the pocket of subdomain IB disrupts the Tyr138-Tyr161 interhelical π-π stacking interaction, which is reflected in the CD spectrum. This phenomenon can be utilized for the CD detection of subdomain IB specific binding of endo- as well as exogenous agents and to study the drug binding associated local conformational adaptation of the HSA molecule.

DOI10.1021/jp4067108
Alternate JournalJ Phys Chem B
PubMed ID24004247