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Directed Evolution of Scanning Unnatural‐Protease‐Resistant (SUPR) Peptides for in Vivo Applications
Author(s) -
Fiacco Stephen V.,
Kelderhouse Lindsay E.,
Hardy Amanda,
Peleg Yonatan,
Hu Biliang,
Ornelas Argentina,
Yang Peiying,
Gammon Seth T.,
Howell Shan M.,
Wang Pin,
Takahashi Terry T.,
Millward Steven W.,
Roberts Richard W.
Publication year - 2016
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.201600253
Subject(s) - protease , in vivo , proteolysis , peptide , amino acid , peptide sequence , peptide library , biochemistry , chemistry , in vitro , biology , enzyme , gene , genetics
Peptides typically have poor biostabilities, and natural sequences cannot easily be converted into drug‐like molecules without extensive medicinal chemistry. We have adapted mRNA display to drive the evolution of highly stable cyclic peptides while preserving target affinity. To do this, we incorporated an unnatural amino acid in an mRNA display library that was subjected to proteolysis prior to selection for function. The resulting “SUPR (scanning unnatural protease resistant) peptide” showed ≈500‐fold improvement in serum stability ( t1 / 2 =160 h) and up to 3700‐fold improvement in protease resistance versus the parent sequence. We extended this approach by carrying out SUPR peptide selections against Her2‐positive cells in culture. The resulting SUPR4 peptide showed low‐nanomolar affinity toward Her2, excellent specificity, and selective tumor uptake in vivo. These results argue that this is a general method to design potent and stable peptides for in vivo imaging and therapy.