RESUMEN
The amino group PEGylation of rhIFNomega with monomethoxy polyethylene glycol succinimidyl succinate (mPEG-SS, 20 000) was investigated, and the modified mixture was separated and purified by ion exchange chromatography and gel filtration chromatography. Under the optimized purification conditions, the average content ofmono PEG-rhIFNomega in the collect liquid reached 182 microg x mL(-1). The average purified yield of mono PEG-rhIFNomega exceed to 22%, and the purity of mono PEG-rhIFNomega was greater than 98% by SDS-PAGE and RP-HPLC. Relative molecular mass of mono PEG-rhIFNomega was 43 790 detected by MALDI-TOF MS. The apparent molecular mass measured by SDS-PAGE was about 60 810. The purified PEG-rhIFNomega has the characteristics of typical PEGylated protein. Activity reservation rate of mono PEG-rhIFNomega was 15.0%, while the antigenicity decreased by at least 64 folds. In addition, the acid stability, thermal stability and stability in serum and trypsin solution of mono PEG-rhIFNomega were markedly better than those of the rhIFNomega. The pharmacological properties of mono PEG-rhIFNomega were significantly improved. The prepared PEG-rhIFNomega might be developed to a novel safe and long-acting interferon.