Heterologous expression and characterisation of mouse brain fatty acid binding protein

A novel brain-type member of the fatty acid binding protein family (B-FABP) was heterologously expressed in Escherichia coli, either as inclusion bodies at 37 degrees C or in soluble form at 22 degrees C. Both B-FABP renatured from inclusion bodies and the solubly expressed protein could be purified to homogeneity by anion exchange chromatography and gel filtration in a functional conformation as they bound oleic acid with high affinity. None of the five cysteines of B-FABP was involved in disulphide bond formation. Isoelectric focusing revealed heterogeneity of the renatured protein but not of the solubly expressed protein. By Western blotting using affinity purified rabbit antibodies raised against the recombinant B-FABP it was demonstrated that in adult mice, B-FABP is predominantly expressed in the olfactory bulb.