Fig. 1

Establishment of a sandwich ELISA for detecting L⁵⁹ LAP-DPs. a Schematic diagram of the ELISA for L⁵⁹ LAP-DPs. In the ELISA, L⁵⁹ LAP-DPs are first captured by coated L59 antibodies (Ab) and then sandwiched by biotin-conjugated anti-LAP antibodies (αLAP-Ab), which form a complex with strep-AP. For detection, an enzyme substrate is added and absorbance at 405 nm was measured. b, c Incubation time- and PLK concentration-dependent increases in the absorbance of the samples containing LAP incubated with PLK. The LAP (final 25 nM) was digested with 12.5 nM (open triangle), 25 nM (open reverse triangle), and 50 nM (open square) PLK, or without PLK (open circle) for 0–90 min, and then the samples were diluted by 1/50 and subjected to the L⁵⁹ LAP-DP ELISA (b). Also, 25 nM rhLAP was digested with 50 nM PLK (open square) or PLN (cross mark), or PLK in the presence of 5 μM camostat mesilate (open diamond) (c). All data were presented as mean ± SD from two different experiments ​*p-value <0.05, **p-value <0.01, ***p-value<0.001 obtained comparing to corresponding control values