Thermal stability of PAD4 mutant enzymes in the absence or presence of calcium ions.

<p>Thermal denaturation of PAD4 mutant enzymes in the presence or absence of 10 mM Ca²⁺ (open and closed circles, respectively). <b>A.</b> N153A. <b>B.</b> N153Q. <b>C.</b> D155A. <b>D.</b> D155E. <b>E.</b> D157A. <b>F.</b> D157E. <b>G.</b> D179A. <b>H.</b> D179E. The experimental data are the mean residue ellipticity at 222 nm ((Θ)₂₂₂) monitored by far-UV CD.