Processing parameters optimization of PEGylation of recombinant human interferon omega

In order to reduce the antigenicity and enhance the stability of the recombinant human interferon omega(rhIFNω)expressed in Pichia pastoris,the amino group modification of rhIFNω with mono-methoxy polyethylene glycol succinimidyl succinate(mPEG-SS,20000)was investigated.It was found that the optimized reaction conditions for the highest modification yield of mono PEG-rhIFNω were as follows:in 50 mmol·L-1 and pH 8.5 phosphate buffer,concentration of rhIFNω 0.75 mg·ml-1,molar ratio of rhIFNω to PEG 1∶7,and reaction time 4 h at 25℃.Under the optimized conditions,the content and modification yield of mono PEG-rhIFNω reached 0.25 mg·ml-1 and 34.63%,respectively.The purified PEG-rhIFNω had the characteristics of typical PEGylated protein.The experiments showed that the antiviral activity of prepared PEG-rhIFNω could retain about 15% of the antiviral activity of the native rhIFNω.