Albumin is the most abundant protein in human blood. It is produced in the liver and has a serum half-life of approximately 19 days. Transporting a large variety of hydrophobic substances like fatty acids, drugs and metabolites is one of its main physiological functions. Beside this it maintains the oncotic pressure and buffers the pH of the blood.
Albumin consists of 585 amino acids, arranged in three mainly helical subunits (I, II, III) each divided into two subdomains (A, B). For long chain fatty acids seven binding sites are known, three of them with high and four with lower affinity.
In recent years low molecular weight biomarkers bound to serum carrier proteins like albumin were intensively investigated assuming they might have a potential for early disease detection.