Murine interleukin-3: Structure, dynamics, and conformational heterogeneity in solution

Abstract

Interleukin-3 (IL-3), a cytokine produced primarily by activated T-cells during immune responses, is a crucial regulator of allergic inflammation. The three-dimensional structure of murine IL-3 (mIL-3) has remained elusive owing to its poor solubility and strong tendency toward aggregation under solution conditions typically used for structural studies. Here we describe the solution properties and structure of mIL-3 determined by NMR using an engineered construct of mIL-3 (mIL-333-156). mIL-3 adopts a four-helical bundle fold, typical of proteins belonging to the short-chain cytokine family, and features a core of highly conserved hydrophobic residues. While significant line broadening and p..