FIGURE 1.
pH and temperature effect on the ABgp46 activity. (A) The pH dependence was measured as the slope of the OD600 nm/min curve, using Pseudomonas aeruginosa OM permeabilized cells as a substrate, suspended in a universal buffer (10 mM KH2PO4, 10 mM Na-citrate, and 10 mM H3BO4), and with pH adjusted from 4.0 to 10.0. (B) The stability was tested by heating the protein at different temperatures (20–60°C) for 30 min, and using OM permeabilized P. aeruginosa PAO1 cells at pH of 8.0. The residual activity shown, is expressed in percentage by comparing with ABgp46 stored at 4°C (=100% relative activity). Averages and standard deviations of four repeated experiments are shown.