Birch pollen profilin: structural organization and interaction with poly-(L-proline) peptides as revealed by NMR

The secondary structure of birch pollen profilin, a potent human allergen, was elucidated by multidimensional nuclear magnetic resonance (NMR), as a prerequisite to study the interaction of this profilin with ligands for its poly-(L-proline) (PLP)-binding site, The chemical shifts of the N-15-labeled backbone amide groups were used to monitor complex formation with various PLP peptides, Titration with deca-L-proline (P-10) yielded a K-D of 0.2 mM. P-8 was the shortest PLP to provoke a significant reaction, (GP(5))(3)G bound significantly, confirming the interaction between profilins and the protein VASP containing this motif, Birch profilin interacted also with GP(6)GP(5), found in the cyclase-associated protein (CAP), it suspected profilin ligand. (C) 1997 Federation of European Biochemical Societies.