Table 1. Affinity of NEMO and ABIN2 ZFs for different types of poly‐ubiquitin chains
KD (chain concentration, μM)
NEMO ZF
 K63‐Tri‐Ub17±2a
 K63‐Poly‐Ub3–716±2
 K48‐Tri‐Ub18±0.5
 Linear tetra‐Ub27±3
ABIN2 ZF
 K63‐Tri‐Ub4±0.7
 K63‐Poly‐Ub3–71.3±0.2
 K48‐Tri‐Ub3±0.3
  • ZF, zinc finger; Ub, ubiquitin.

  • a The affinity of N‐terminally fluorescein‐coupled peptides for poly‐ubiquitin chains was measured as described under section Materials and methods. The affinity for monoubiquitin was too weak to be measured by this technique in the presence of 150 mM KCl. However, we previously calculated a value of 253±15 μM using an F395W mutant (to allow fluorescence measurement) of the human NEMO ZF in a buffer without salt (Cordier et al, 2009).