Sortase-catalyzed transformations that improve the properties of cytokines

Recombinant protein therapeutics often suffer from short circulating half-life and poor stability, necessitating multiple injections and resulting in limited shelf-life. Conjugation to polyethylene glycol chains (PEG) extends the circulatory half-life of many proteins, but the methods for attachment...

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Bibliographic Details
Main Authors: Dougan, Stephanie K., Chuang, Tzu-Ying, Spooner, Eric, Ploegh, Hidde, Popp, Maximilian W.L.
Other Authors: Massachusetts Institute of Technology. Department of Biology
Format: Article
Language:en_US
Published: National Academy of Sciences (U.S.) 2011
Online Access:http://hdl.handle.net/1721.1/65875
https://orcid.org/0000-0002-1090-6071
Description
Summary:Recombinant protein therapeutics often suffer from short circulating half-life and poor stability, necessitating multiple injections and resulting in limited shelf-life. Conjugation to polyethylene glycol chains (PEG) extends the circulatory half-life of many proteins, but the methods for attachment often lack specificity, resulting in loss of biological activity. Using four-helix bundle cytokines as an example, we present a general platform that uses sortase-mediated transpeptidation to facilitate site-specific attachment of PEG to extend cytokine half-life with full retention of biological activity. Covalently joining the N and C termini of proteins to obtain circular polypeptides, again executed using sortase, increases thermal stability. We combined both PEGylation and circularization by exploiting two distinct sortase enzymes and the use of a molecular suture that allows both site-specific PEGylation and covalent closure. The method developed is general, uses a set of easily accessible reagents, and should be applicable to a wide variety of proteins, provided that their termini are not involved in receptor binding or function.