Structure of monomeric Interleukin-8 and its interactions with the N-terminal Binding Site-I of CXCR1 by solution NMR spectroscopy
Abstract
The structure of monomeric human chemokine IL-8 (residues 1â??66) was determined in aqueous solution by NMR spectroscopy. The structure of the monomer is similar to that of each subunit in the dimeric full-length protein (residues 1â??72), with the main differences being the location of the N-loop (residues 10â??22) relative to the C-terminal α-helix and the position of the side chain of phenylalanine 65 near the truncated dimerization interface (residues 67â??72). NMR was used to analyze the interactions of monomeric IL-8 (1â??66) with ND-CXCR1 (residues 1â??38), a soluble polypeptide corresponding to the N-terminal portion of the ligand binding site (Binding Site-I) of the chemokine receptor CXCR1 in aqueous solution, and with 1TM-CXCR1 (residues 1â??72), a membrane-associated polypeptide that includes the same N-terminal portion of the binding site, the first
trans-membrane helix, and the first intracellular loop of the receptor in nanodiscs. The presence of neither the first transmembrane helix of the receptor nor the lipid bilayer significantly affected the interactions of IL-8 with Binding Site-I of CXCR1.
Source: Journal of Biomolecular NMR