sentence: Recombinant WT ( 100 μ M , in 50 mM Tris , pH 7.5 , 150 mM KCl , 0.05 % NaN buffer ) and G51D ( 100 μ M , in 50 mM phosphate buffer , pH 7.0 , 50 mM NaCl , 0.05 % NaN buffer ) were shaking at 37 ° C , 900 rpm in ThermoMixer ( Eppendorf ) for 7 days , respectively .