Effect of triethanolamine on inhibition of OPH-catalyzed hydrolysis of DFP by fluoride (NaF) given at a later reaction stage.

<p>The velocity (<i>V</i>) for OPH-catalyzed hydrolysis of DFP under 0 (○) and 300 mM (□) TEA condition was determined once per minute with adding of 3 mM NaF (inhibitor) at the end of the first 5 minutes, i.e. at the beginning of 6^th minute in total reaction time (10 minutes). The DFP concentration used was 20 mM, and the other reaction conditions and statistics analysis were the same as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0169937#pone.0169937.g004" target="_blank">Fig 4</a>. The black arrows (up and down) both indicated the time point to add NaF with final concentration (3 mM), and the dotted vertical line in the diagram indicated the first time-point to make record after NaF adding.