FIGURE 1.

Affinity chromatographic purification of rStrep-PlaB and PLA activity. A, Coomassie-stained 12.5% SDS-PAGE of affinity chromatography fractions (1-ml Strep-Tactin column) from rStrep-PlaB expressed from a 1-liter culture of E. coli BL21 (pKK19). Lane 1, soluble supernatant after cell disruption; lane 2, flow-through; lanes 3–5, washing fractions; and lanes 6–12, elution fractions. B, release of free fatty acids (FFA) was detected after incubation of 0.01 μg/ml (0.186 nm) purified rStep-PlaB with phospholipids for 60 min. The result represents the means ± S.D. of triplicate samples and is representative for at least three experiments. PG, dipalmitoylphosphatidylglycerol; PC, dipalmitoylphosphatidylcholine; LPG, 1-monopalmitoyl-lysophosphatidylglycerol; LPC, 1-monopalmitoyl-lysophosphatidylcholine; M, molecular weight standard.