Structural and functional studies on different human FABP types

Interaction of various ligands with recombinant proteins of 5 human FABP ty pes was studied by radiochemical and fluorescence procedures. Liver, heart, intestinal and myelin FABP showed a higher affinity for oleic acid than ad ipocyte FABP. Intestinal and adipocyte FABP had a relatively high K-d value for arachidonic acid. Liver and intestinal FABP showed high affinity for D AUDA in contrast to the other FABP types. ANS was only well bound by liver and adipocyte FABP. Retinol was not bound by any FABP type, retinoic acid o nly by adipocyte FABP. Data indicate the importance of both electrostatic a nd hydrophobic interaction for the ligand-FABP binding. The immunological c rossreactivity between six human FABP types including epidermal FABP and th eir respective antibodies raised in rabbit, chicken and mouse appeared to b e low and may suggest heterogeneity of protein surface.