Figure 2.

Biochemical characterization of SFP aldolases.A, HPLC mass spectrometry (triple quadrupole, QqQ) chromatograms showing YaSqiA- (class II aldolase) catalyzed conversion of 6-deoxy-6-sulfofructose-1-phosphate (SFP) to 3-sulfolactaldehyde (SLA) and dihydroxyacetone phosphate (DHAP) at time (t) = 0, 10, 30 min. B, metal ion dependence of YaSqiA. As-purified protein was assessed for activity using SFP as substrate in the absence (−) or presence of EDTA. Demetalated YaSqiA was obtained by treatment with Chelex resin and supplemented with various divalent cations and assessed for activity with SFP as substrate. C and D, Michaelis–Menten and Lineweaver–Burk plots for reaction rates measured using SFP as substrate, for YaSqiA and HpSqiA, respectively. In all experiments, error bars represent SEM, n = 3.