Human Serum Albumin Loaded with Fatty Acids Reveals Complex Protein-Ligand Thermodynamics and Boleadora-Type Solution Dynamics Leading to Gelation.
J��rg Reichenwallner, Sebastian Michler, Christian Schwieger, Dariush Hinderberger
Author Information
J��rg Reichenwallner: Institute of Chemistry, Physical Chemistry - Complex Self-Organizing Systems, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
Sebastian Michler: Institute of Chemistry, Physical Chemistry - Complex Self-Organizing Systems, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
Christian Schwieger: Institute of Chemistry, Physical Chemistry - Complex Self-Organizing Systems, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany. ORCID
Dariush Hinderberger: Institute of Chemistry, Physical Chemistry - Complex Self-Organizing Systems, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany. ORCID
Using an electron paramagnetic resonance (EPR) spectroscopic strategy that has been developed for core-shell polymers, the complexity of the binding of fatty acids to human serum albumin (HSA) is characterized in detail. We unravel the internal dynamics of HSA solutions with fatty acids by applying continuous wave EPR (CW EPR) from which we derive a consistent thermodynamic interpretation about fatty acid interactions with HSA in the investigated temperature range of 5-97 ��C. Additionally, data from CW EPR are corroborated by dynamic light scattering (DLS), differential scanning calorimetry (DSC) and nanoscale distance measurements using double electron-electron resonance (DEER) spectroscopy. We discuss our data in light of decades of biophysical studies on albumin and aim at drawing a complete functional and dynamic picture of HSA "at work". This picture suggests that HSA is built from modular, rotationally decoupled domains that resemble an entangled three-piece in solution.
