title: Engineering a targeted delivery platform using Centyrins.
abstract: Targeted delivery of therapeutic payloads to specific tissues and cell types is an important component of modern pharmaceutical development. Antibodies or other scaffold proteins can provide the cellular address for delivering a covalently linked therapeutic via specific binding to cell-surface receptors. Optimization of the conjugation site on the targeting protein, linker chemistry and intracellular trafficking pathways can all influence the efficiency of delivery and potency of the drug candidate. In this study, we describe a comprehensive engineering experiment for an EGFR binding Centyrin, a highly stable fibronectin type III (FN3) domain, wherein all possible single-cysteine replacements were evaluated for expression, purification, conjugation efficiency, retention of target binding, biophysical properties and delivery of a cytotoxic small molecule payload. Overall, 26 of the 94 positions were identified as ideal for cysteine modification, conjugation and drug delivery. Conjugation-tolerant positions were mapped onto a crystal structure of the Centyrin, providing a structural context for interpretation of the mutagenesis experiment and providing a foundation for a Centyrin-targeted delivery platform.
authors.affiliation: Janssen Research and Development, L.L.C., 1400 McKean Road, Spring House, PA 19477, USA.
authors.forename: Shalom D
authors.initials: SD
authors.lastname: Goldberg
authors.affiliation: Janssen Research and Development, L.L.C., 1400 McKean Road, Spring House, PA 19477, USA.
authors.forename: Rosa M F
authors.initials: RM
authors.lastname: Cardoso
authors.affiliation: Janssen Research and Development, L.L.C., 1400 McKean Road, Spring House, PA 19477, USA.
authors.forename: Tricia
authors.initials: T
authors.lastname: Lin
authors.affiliation: Janssen Research and Development, L.L.C., 1400 McKean Road, Spring House, PA 19477, USA.
authors.forename: Tracy
authors.initials: T
authors.lastname: Spinka-Doms
authors.affiliation: Janssen Research and Development, L.L.C., 1400 McKean Road, Spring House, PA 19477, USA.
authors.forename: Donna
authors.initials: D
authors.lastname: Klein
authors.affiliation: Janssen Research and Development, L.L.C., 1400 McKean Road, Spring House, PA 19477, USA.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Jacobs
authors.affiliation: Janssen Research and Development, L.L.C., 1400 McKean Road, Spring House, PA 19477, USA.
authors.forename: Vadim
authors.initials: V
authors.lastname: Dudkin
authors.affiliation: Janssen Research and Development, L.L.C., 1400 McKean Road, Spring House, PA 19477, USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Gilliland
authors.affiliation: Janssen Research and Development, L.L.C., 1400 McKean Road, Spring House, PA 19477, USA KOneil@its.jnj.com.
authors.forename: Karyn T
authors.initials: KT
authors.lastname: O'Neil
mesh_terms: D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D018360:Crystallography, X-Ray; D004337:Drug Carriers / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism; D005353:Fibronectins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D008301:Maleimides / Q000737:chemistry; D008958:Models, Molecular; D000072757:Protein Conformation, beta-Strand; D000072417:Protein Domains; D015202:Protein Engineering
chemical_list: D004337:Drug Carriers; D005353:Fibronectins; D008301:Maleimides; C043592:maleimide; D066246:ErbB Receptors
keywords: centyrin, cysteine scanning, EGFR, FN3 domain, targeted delivery