Properties of a stationary phase based on immobilised chicken liver basic fatty acid-binding protein

The fatty acid-binding proteins (FABPs) are a class of low-molecular-mass proteins that bind fatty acids and are thought to be involved in their intracellular transport. FABPs have been isolated and studied from several tissues, but their precise function and mechanism of action are still not clear. Chicken liver (basic) fatty acid-binding protein (bFABP) was immobilised on aminopropyl silica and the developed stationary phase was used to examine the enantioselective properties of this protein and to study the binding of drugs to bFABP. The retention and enantioselectivity of the new column for a large number of chiral drugs was investigated. The enantiomers of basic and neutral compounds were poorly retained and not resolved by the bFABP column. On the contrary the resolution of the enantiomers of some acidic compounds was obtained. Therefore the influence of the mobile phase pH and organic modifier on the chromatographic performance of acidic compounds was studied. In order to clarify the retention mechanism, competitive displacement studies were also carried out by adding short-chain fatty acids to the mobile phase as displacing agents and preliminary quantitative structure-retention relationship correlations were developed to describe the nature of the interactions between the chemical structures of the analytes and the observed chromatographic results.