Purification and partial structural characterization of a fatty acid-binding protein from the liver of the South American armadillo Chaetophractus villosus.

The fatty acid-binding protein (FABP) from armadillo liver was purified to homogeneity by a procedure involving gel filtration and two anion exchange chromatography steps. The purified protein proved to have a pI between 5.0 and 5.2 and migrated by sodium dodecyl sulfate-polyacrilamyde gel electrophoresis as a single entity of approximately 14 kDa. The armadillo FABP cross-reacted with antiserum against rat liver FABP but not against rat intestinal FABP. The same as other members of the family, it has a blocked N-terminus. Amino acid sequencing of peptides obtained by cyanogen bromide cleavage and in-gel tryptic digestion shows that the armadillo, despite being one of the less evolved mammals, has a liver FABP of the same type as that of highly evolved mammals.