1NAP

THE CRYSTAL STRUCTURE OF RECOMBINANT HUMAN NEUTROPHIL-ACTIVATING PEPTIDE-2 (M6L) AT 1.9-ANGSTROMS RESOLUTION

Summary for 1NAP

• Entry DOI: 10.2210/pdb1nap/pdb
• Descriptor: NEUTROPHIL ACTIVATING PEPTIDE-2 (2 entities in total)
• Functional Keywords: cytokine
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 4
• Total formula weight: 30495.74

Authors

Malkowski, M.G.,Edwards, B.F.P. (deposition date: 1994-12-19, release date: 1995-12-19, Last modification date: 2024-11-06)

Primary citation

Malkowski, M.G.,Wu, J.Y.,Lazar, J.B.,Johnson, P.H.,Edwards, B.F.
The crystal structure of recombinant human neutrophil-activating peptide-2 (M6L) at 1.9-A resolution.
J.Biol.Chem., 270:7077-7087, 1995

PubMed Abstract: Neutrophil-activating peptide-2 (NAP-2) is a 70-residue carboxyl-terminal fragment of platelet basic protein, which is found in the alpha-granules of human platelets. NAP-2, which belongs to the CXC family of chemokines that includes interleukin-8 and platelet factor 4, binds to the interleukin-8 type II receptor and induces a rise in cytosolic calcium, chemotaxis of neutrophils, and exocytosis. Crystals of recombinant NAP-2 in which the single methionine at position 6 was replaced by leucine to facilitate expression belong to space group P1 (unit cell parameters a = 40.8, b = 43.8, and c = 44.7 A and alpha = 98.4 degrees, beta = 120.3 degrees, and gamma = 92.8 degrees), with 4 molecules of NAP-2 (Mr = 7600) in the asymmetric unit. The molecular replacement solution calculated with bovine platelet factor 4 as the starting model was refined using rigid body refinement, manual fitting in solvent-leveled electron density maps, simulated annealing, and restrained least squares to an R-factor of 0.188 for 2 sigma data between 7.0- and 1.9-A resolution. The final refined crystal structure includes 265 solvent molecules. The overall tertiary structure, which is similar to that of platelet factor 4 and interleukin-8, includes an extended amino-terminal loop, three strands of antiparallel beta-sheet arranged in a Greek key fold, and one alpha-helix at the carboxyl terminus. The Glu-Leu-Arg sequence that is critical for receptor binding is fully defined by electron density and exhibits multiple conformations.

PubMed: 7706245
DOI: 10.1074/jbc.270.13.7077

Experimental method

X-RAY DIFFRACTION (1.9 Å)