Figure 4

Summary of the specific intermolecular interactions monitored both at the “site1” and “site2” of ^hC5a-C5aR complex over 250 ns of MD at 300 K in POPC bilayer. Interacting residues that are not superscripted represents C5aR and the residues that are superscripted represents ^hC5a. The solid grey lines indicate the cut-off distance. (a) Moderate salt bridge interaction monitored between the D2 and H⁶⁷. (b) Strong “cation-π” interaction observed between Y11 and R³⁷. (c) Stable “π-π” interaction observed between Y14 and F⁵¹. (d) Strong hydrogen bonding noted between the side chain of D16 and the backbone NH of N²⁹. (e) Strong hydrogen bond noted between the backbone carbonyl of D18 and the side chain NH of R⁶². (f) Stable salt bridge interactions observed between the terminal NH₃⁺ of M¹ and side chain of D21 and (g) D27. (h) Strong “π-π” interaction observed between F182 and H⁶⁷. (i) Moderate salt bridge interaction noted between the side chain of D191 and the terminal CO₂⁻ of R⁷⁴. (j) Strong hydrogen bond between side chain of S193 and terminal CO₂⁻ of R⁷⁴. (k) Very strong hydrogen bond interaction between side chain of E269 and the backbone NH of I⁶⁵. (l) Stable “cation-π” interaction observed between F275 and K⁶⁸.