387955 Site-Specific Fatty Acid Conjugation to Prolong Protein Half-Life in Vivo

Monday, November 17, 2014: 9:42 AM
201 (Hilton Atlanta)
Sung In Lim1, Yong Hwan Kim2 and Inchan Kwon1,3, (1)Department of Chemical Engineering, University of Virginia, Charlottesville, VA, (2)Dept. of Chemical Engineering, Kwangwoon University, Seoul, South Korea, (3)Schools of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea

Therapeutic proteins often suffer short serum half-life. In order to extend the serum half-life, a natural albumin ligand (a fatty acid) has been conjugated to small therapeutic peptides resulting in a prolonged serum half-life via binding to patients’ serum albumin in vivo. However, fatty acid-conjugation has limited applicability due to lack of site-specificity resulting in the heterogeneity of conjugated proteins and a significant loss in pharmaceutical activity. In order to address these issues, we exploited the site-specific fatty acid-conjugation to a permissive site of a protein, using copper-catalyzed alkyne-azide cycloaddition, by linking a fatty acid derivative to p-ethynylphenylalanine incorporated into a protein using an engineered pair of yeast tRNA/aminoacyl tRNA synthetase. As a proof-of-concept, we show that single palmitic acid conjugated to superfolder green fluorescent protein (sfGFP) in a site-specific manner enhanced a protein’s albumin-binding in vitro about 20 times and the serum half-life in vivo 5 times when compared to those of the unmodified sfGFP. Furthermore, the fatty acid conjugation did not cause a significant reduction in the fluorescence of sfGFP. As an extension of this work, we have been investigating whether the site-specific fatty acid conjugation to one therapeutic protein can prolong its serum half-life with retained therapeutic activity. Fatty acid-conjugated therapeutic protein variants were successfully prepared with fully retained therapeutic activity. Pharmacokinetic analysis of the therapeutic protein variants are being performed.

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See more of this Session: Drug Delivery II
See more of this Group/Topical: Food, Pharmaceutical & Bioengineering Division