Table 4 Kd and relative saturation of HS-binding sites of the 3.class CXCL8 mutants, as determined by IFTs, compared with wtCXCL8

Ligand: unfractionated HS. A high degree of fluorescence quenching refers to tighter binding of the HS ligand leading to more efficient deactivation of the emission.

wtCXCL8 or mutantKd (×10−6 M)/unfractionated HSFinal degree of fluorescence quenching (max. ΔF/F0) in%)
wtCXCL80.46±0.07215
CXCL8(Δ6F17RF21RE70K)0.103±0.015227
CXCL8(Δ6F17RF21RE70RN71K)0.107±0.009122
CXCL8(Δ6F17RF21RE70KN71R)0.237±0.061424
CXCL8(Δ6F17RF21RN71K)0.209±0.014532
CXCL8(Δ6F17KF21KE70KN71K)0.097±0.008138