Nature Biotechnology
17, 793 - 797 (1999)
doi:10.1038/11737
Evolution of a cytokine using DNA family shufflingChia-Chun J. Chang1, 2, Teddy T. Chen1, 2, Brett W. Cox1, Glenn N. Dawes1, Willem P.C. Stemmer1, Juha Punnonen1
& Phillip A. Patten11
Maxygen, Inc., 3410 Central Expressway, Santa Clara, CA 95051. 2
These authors contributed equally to this work.
Correspondence should be addressed to Phillip A. Patten phil_patten@maxygen.comDNA shufflingcytokinesinterferonmolecular breedingpharmaceutical proteinsDNA shuffling of a family of over 20 human interferon- (Hu-IFN-) genes was used to derive variants with increased antiviral and antiproliferation activities in murine cells. A clone with 135,000-fold improved specific activity over Hu-IFN-2a was obtained in the first cycle of shuffling. After a second cycle of selective shuffling, the most active clone was improved 285,000-fold relative to Hu-IFN-2a and 185-fold relative to Hu-IFN-1. Remarkably, the three most active clones were more active than the native murine IFN-s. These chimeras are derived from up to five parental genes but contained no random point mutations. These results demonstrate that diverse cytokine gene families can be used as starting material to rapidly evolve cytokines that are more active, or have superior selectivity profiles, than native cytokine genes.
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