摘要：

Recombinant (mIL-22) and its variants encoding four muteins (Y51A, N54A, R55A and E117A) were expressed in , refolded and purified to homogeneity as monomeric by one-step ion-exchange chromatography. The of and its four muteins to immobilized mIL-22 receptor α1 domain (mIL-22 Rα1-) exhibited similar affinity, indicating that the single-amino-acid mutations do not affect its properties. Similarly, no differences were found in to expressed on the surface of , although the affinity of all five to the was higher than that to Rα1-. In an in vitro bioassay, recombinant mIL-22 stimulated in HepG2 , whereas the four muteins were completely (Y51A) or almost completely (N54A, R55A and E117A) devoid of this agonistic activity. Furthermore, the agonistic activity of mIL-22 could be inhibited in a dose-dependent manner by the four muteins with almost identical efficiency. mIL-22 and its Y51A mutein were pegylated by -propionylaldehyde-20 kDa, yielding a mixture of mono (75-80%) and double (20-25%) pegylated . The pegylated showed lower affinity (50 and 25%) toward immobilized mIL-22 Rα1-than their non-pegylated analogs. Wild-type pegylated exhibited 5- to 10-fold lower activity in the HepG2 bioassay than its non-pegylated counterpart. Preparation of recombinant mIL-22 antagonists provides new tools for the study of activity and of eventual therapeutic means for attenuating its negative effects.

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