NMR analysis of drug binding to domain III of Human serum albumin


Rodés Guirao, Marta 


Human serum albumin, also known as HSA, is the most abundant protein in the plasma with an average concentration of 0.6 mM in the blood circulation. It has a high capacity of interacting with a wide range of molecules like fatty acids, hormones, other proteins or small molecules and, in many cases, these molecules are transported while bounded to HSA. From the point of view of drug discovery, it is very important to study the interaction with drugs because it may affect their pharmacokinetics, as the bioavailability of molecules that travel through the blood circulation depend on their binding strength to albumin.
We have used nuclear magnetic resonance techniques (NMR) in order to study the binding properties of HSA with two small molecules: propofol and oxyphenbutazone. Although it would have been interesting to study the whole protein, it’s very large size (66 kDa) makes it no suitable for NMR studies. Therefore, we have focus on Domain III (DIII) (23 kDa) which has been expressed in E. coli and enriched with isotopes for NMR. DIII plays an important role upon the binding of drugs as one of the two principal drug binding sites is located in this domain. Moreover, it is the main domain involved in the binding to the neonatal Fc receptor (FcRn) allowing for its recycling and life extension.
The signals of the HSQC can be assigned to the third domain of the protein structure, and chemical shift perturbations resulting from the titration of the known drugs will report an interaction between the drug and the protein.



Mulder, Frans A.A.
Batllori Aguilà, Xavier  


IQS SM - Master’s Degree in Pharmaceutical Chemistry