Investigation of lysine side chain interactions of interleukin-8 with heparin and other glycosaminoglycans studied by a methylation-NMR approach

摘要: Although the interaction between interleukin-8 (IL-8) and glycosaminoglycans (GAGs) is crucial for mediation of inflammatory effects, little known about site specificity this interaction. Therefore, we studied complexes IL-8 heparin (HEP) as well other GAGs in a multidisciplinary approach, involving site-directed mutagenesis, mass spectrometry, fluorescence solution NMR spectroscopy computer modeling. The GAG largely driven by amine groups lysine guanidinium arginine side chains. However, due to fast exchange with solvent, it typically not possible detect signals those groups. Here, applied reductive (13)C-methylation chains providing sensitive probes monitoring directly sites (1)H-(13)C correlation experiments. We focused on K25, K28, K59, K69 K72 (1-77), which were reported be involved binding GAGs. these residues assigned HSQC spectra through help mutagenesis. titration experiments combination molecular docking dynamics simulations investigate involvement each HEP various hexasaccharides. identified most relevant anchors IL-8(1-77) analyzed