publications by Ashutosh Chilkoti.


Papers Published

  1. Gao, W; Liu, W; Christensen, T; Zalutsky, MR; Chilkoti, A, In situ growth of a PEG-like polymer from the C terminus of an intein fusion protein improves pharmacokinetics and tumor accumulation., Proceedings of the National Academy of Sciences of USA, vol. 107 no. 38 (September, 2010), pp. 16432-16437, National Acad Sciences [20810920], [doi] .
    (last updated on 2017/09/20)

    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.