[Analyze the bioactivity of PD-1 and PD-L1 recombination protein which expressed by prokaryotic system]

To analyze the interaction of PD-1 and PD-L1 recombination protein and to know their bioactivity and affinity.

Stick the PD-1 protein on the surface of CM5 sensor chip by the method of Ammine coupling after being preconsentrated. Dilute the PD-L1 protein step by step and reject it to the passage on CM5 sensor chip which had been stick by PD-1. The time of combination is 3 minutes and of separation is 15 minutes, respectively. Observe the procession and analyze data by BIA Evaluation software 4.

On the consistency of 40 microg/ml, pH 4.5, the PD-1 protein could couple steady on the surface of CM5sensor chip, RU is 3300. On the density of 200 mmol/ml PD-L1 could combine with PD-1 specifically, RU = 150, K(D) = 3.5 x 10(-6).

The PD-1 and PD-L1 recombination protein which we expressed by prokaryotic system have good affinity and bioactivity. The results could provide basic condition for later study.