کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2184868 1095943 2011 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Interactions of Interleukin-8 with the Human Chemokine Receptor CXCR1 in Phospholipid Bilayers by NMR Spectroscopy
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Interactions of Interleukin-8 with the Human Chemokine Receptor CXCR1 in Phospholipid Bilayers by NMR Spectroscopy
چکیده انگلیسی

CXCR1 is a receptor for the chemokine interleukin-8 (IL-8), a mediator of immune and inflammatory responses. Strategically located in the cell membrane, CXCR1 binds to IL-8 with high affinity and subsequently transduces a signal across the membrane bilayer to a G-protein-activated second messenger system. Here, we describe NMR studies of the interactions between IL-8 and human CXCR1 in lipid environments. Functional full-length and truncated constructs of CXCR1 and full-length IL-8 were uniformly 15N-labeled by expression in bacteria followed by purification and refolding. The residues responsible for interactions between IL-8 and the N-terminal domain of CXCR1 were identified by specific chemical shift perturbations of assigned resonances on both IL-8 and CXCR1. Solution NMR signals from IL-8 in q = 0.1 isotropic bicelles disappeared completely when CXCR1 in lipid bilayers was added in a 1:1 molar ratio, indicating that binding to the receptor-containing bilayers immobilizes IL-8 (on the ∼ 105 Hz timescale) and broadens the signals beyond detection. The same solution NMR signals from IL-8 were less affected by the addition of N-terminal truncated CXCR1 in lipid bilayers, demonstrating that the N-terminal domain of CXCR1 is mainly responsible for binding to IL-8. The interaction is tight enough to immobilize IL-8 along with the receptor in phospholipid bilayers and is specific enough to result in well-aligned samples in oriented sample solid-state NMR spectra. A combination of solution NMR and solid-state NMR studies of IL-8 in the presence of various constructs of CXCR1 enables us to propose a model for the multistep binding process.

Research Highlights
► IL-8 and CXCR1 interactions were dissected using isotopically labeled proteins.
► Isotropic and aligned protein-containing bicelles were used in these studies.
► A complex of IL-8, CXCR1, and the phospholipid bilayer is the essential species.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Biology - Volume 414, Issue 2, 25 November 2011, Pages 194–203
نویسندگان
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