Figure 1.

The role of the number of carbon atoms in the phospholipid chains and the amide in the Brown spider recombinant phospholipase-D (LiRecDT1) activity. (A) Structures of the different sphingomyelins tested. (B) Catalytic activity on different sphingomyelins. Control: incubation of Amplex Red reagent and substrate without the enzyme. PLD activity was measured using the Amplex Red kit (Invitrogen). LiRecDT1 toxin (1 µg) was added to different substrates (250 µM) and the Amplex Red reagent mixture. After incubation (30 min, 37 °C), fluorescence was measured by fluorimeter, excitation 540 nm, and emission 570 nm (Tecan Infinite M200). The values represent average ± SD of three independent experiments carried out in triplicate (**** p < 0.001 and “ns”: non-significant).