Fig. 4.

Illustrations of the C5a-prednisone complexes, highlighting the nanomolar to micromolar binding range of prednisone, nestled inside the defined “hotspot” of C5a. Prednisone highlighted in the CPK model is presented in complex with the respective central conformer of the (a) cluster 1, (b) cluster 2 and (c) cluster 3 of C5a evolved over the duration of MD. One of the fluorophore of C5a (Tyr 23) closest to the illustrated binding site is highlighted in stick. Prednisone binding interlocks the side chain of Arg74, presented in stick is known to be highly important for biomolecular signaling of C5a. The binding site of the C5a is rendered in typical “blue-white-brown” surface mode to indicate the contribution of both hydrophilic (blue) and hydrophobic (brown) side chains of different amino acids.