Determination of the secondary structural elements of chicken liver fatty acid binding protein by two-dimensional homonuclear NMR.

A conformational study in solution of the fatty acid binding protein from chicken liver is presented. The nearly complete sequence-specific 1H resonance assignment was achieved from homonuclear two-dimensional nmr experiments using a sample of native protein. The principal elements of secondary structure were identified: 10 antiparallel beta-strands and one helical segment followed by a turn comprising 5 residues. These elements correspond closely with those of the crystal structure of the related protein, and two new secondary structural features obtained from the nmr data are the beta-sheet conformation between the first and the last beta-strand in the protein sequence, as well as a helical loop at the N-terminus of the polypeptide chain.