Abstract
Chemkines play an important role in the neutrophil-mediated inflammation in human pathophysiology. ELR-CXC chemkines belong to the CXC subfamily of chemkines with ELR-motif at the N-terminal region. The ELR-CXC chemokines play an important role in inflammatory responses to many pathogenic insults as their ability to chemoattract and activate neutrophils via CXC receptor. The analogue of CXCL8 (IL-8) in which two residues were mutated (IL8K11R/G31P) can effectively block neutrophil responses via CXCR1 and CXCR2. We measured the spin-lattice relaxation rate R1, spin-spin relaxation rate R2 and 15N {H} nuclear overhauser enhancement (NOE) of IL8K11R/G31P at 14.09T. The programs pdbinteria and R2R1_diffusion were used to estimate the diffusion tensor and generate a new pdb file. Then, Model-free formalism was performed to determine the order parameter (S2), the correlation time of local motion (τe) and the chemical exchange contribution (Rex). The reduced spectral density functions at different frequencies were also used to obtain the relaxation information. These analysis provided information that backbone dynamics of IL8K11R/G31P around Arg11 and Pro31 are more flexible than other region.