In situ growth of a PEG-like polymer from the C terminus of an intein fusion protein improves pharmacokinetics and tumor accumulation.


Journal Article

This paper reports a general in situ method to grow a polymer conjugate solely from the C terminus of a recombinant protein. GFP was fused at its C terminus with an intein; cleavage of the intein provided a unique thioester moiety at the C terminus of GFP that was used to install an atom transfer radical polymerization (ATRP) initiator. Subsequent in situ ATRP of oligo(ethylene glycol) methyl ether methacrylate (OEGMA) yielded a site-specific (C-terminal) and stoichiometric conjugate with high yield and good retention of protein activity. A GFP-C-poly(OEGMA) conjugate (hydrodynamic radius (R(h)): 21 nm) showed a 15-fold increase in its blood exposure compared to the protein (R(h): 3.0 nm) after intravenous administration to mice. This conjugate also showed a 50-fold increase in tumor accumulation, 24 h after intravenous administration to tumor-bearing mice, compared to the unmodified protein. This approach for in situ C-terminal polymer modification of a recombinant protein is applicable to a large subset of recombinant protein and peptide drugs and provides a general methodology for improvement of their pharmacological profiles.

Full Text

Duke Authors

Cited Authors

  • Gao, W; Liu, W; Christensen, T; Zalutsky, MR; Chilkoti, A

Published Date

  • September 21, 2010

Published In

Volume / Issue

  • 107 / 38

Start / End Page

  • 16432 - 16437

PubMed ID

  • 20810920

Pubmed Central ID

  • 20810920

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

Digital Object Identifier (DOI)

  • 10.1073/pnas.1006044107


  • eng

Conference Location

  • United States