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Cystine‐knot peptides targeting cancer‐relevant human cytotoxic T lymphocyte‐associated antigen 4 (CTLA‐4)
Author(s) -
Maaß Franziska,
WüstehubeLausch Joycelyn,
Dickgießer Stephan,
Valldorf Bernhard,
Reinwarth Michael,
Schmoldt HansUlrich,
Daneschdar Matin,
Avrutina Olga,
Sahin Ugur,
Kolmar Harald
Publication year - 2015
Publication title -
journal of peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 66
eISSN - 1099-1387
pISSN - 1075-2617
DOI - 10.1002/psc.2782
Subject(s) - chemistry , cytotoxic t cell , fusion protein , peptide , antigen , biochemistry , microbiology and biotechnology , biology , in vitro , immunology , gene , recombinant dna
Cystine‐knot peptides sharing a common fold but displaying a notably large diversity within the primary structure of flanking loops have shown great potential as scaffolds for the development of therapeutic and diagnostic agents. In this study, we demonstrated that the cystine‐knot peptide MCoTI‐II, a trypsin inhibitor from Momordica cochinchinensis , can be engineered to bind to cytotoxic T lymphocyte‐associated antigen 4 (CTLA‐4), an inhibitory receptor expressed by T lymphocytes, that has emerged as a target for the treatment of metastatic melanoma. Directed evolution was used to convert a cystine‐knot trypsin inhibitor into a CTLA‐4 binder by screening a library of variants using yeast surface display. A set of cystine‐knot peptides possessing dissociation constants in the micromolar range was obtained; the most potent variant was synthesized chemically. Successive conjugation with neutravidin, fusion to antibody Fc domain or the oligomerization domain of C4b binding protein resulted in oligovalent variants that possessed enhanced (up to 400‐fold) dissociation constants in the nanomolar range. Our data indicate that display of multiple knottin peptides on an oligomeric scaffold protein is a valid strategy to improve their functional affinity with ramifications for applications in diagnostics and therapy. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.