Site-specific PEGylation of Engineered Cysteine Analogues of Recombinant Human Interleukin-11 / 中国生物工程杂志

Human Interleukin-11(hIL-11)has no Cys residue in its natural form.By site-directed mutagenesis,a Cys residue can be introduced to replace the 1st residue Gly and the rhIL-11 was chemically modified by using 20 kDa mPEG-maleimide conjugated to this site.The mPEG-hIL-11 conjugate was purified and showed a single band on SDS-PAGE with an apparent molecular weight.The biological activity of purified mPEG-hIL-11 was determined using a dependent cell line 7TD1.The remaining biological activity of PEGylated-rhIL-11 was 30% of native rhIL-11,suggesting chemical modification of rhIL-11 by PEG is a promising approach for improving the pharmacological efficacy.