SECONDARY STRUCTURE OF NEUTROPHIL-ACTIVATING PEPTIDE-2 DETERMINED BY H-1-NUCLEAR MAGNETIC-RESONANCE SPECTROSCOPY

Neutrophil-activating protein-2 (NAP-2) is a 72 residue protein demons trating a range of proinflammatory activities. The solution structure of monomeric NAP-2 has been investigated by two-dimensional H-1-n.m.r. spectroscopy. Sequence-specific proton resonance assignments have bee n made and secondary structural elements have been identified on the b asis of nuclear Overhauser data, coupling constants and amide hydrogen /deuteron exchange. The NAP-2 monomer consists of a triple-stranded an ti-parallel beta-sheet arranged in a 'Greek key' and a C-terminal heli x (residues 59-70) and is very similar to that found in the n.m.r. sol ution conformation of dimeric interleukin-8 and the crystal structure of tetrameric bovine platelet factor-4. Results are discussed in terms of heparin binding and neutrophil-activation properties of NAP-2.