title: Disulfide-Depleted Selenoconopeptides: a Minimalist Strategy to Oxidative Folding of Cysteine-Rich Peptides.
abstract: Despite the therapeutic promise of disulfide-rich, peptidic natural products, their discovery and structure/function studies have been hampered by inefficient oxidative folding methods for their synthesis. Here we report that converting the three disulfide-bridged mu-conopeptide KIIIA into a disulfide-depleted selenoconopeptide (by removal of a noncritical disulfide bridge and substitution of a disulfide- with a diselenide-bridge) dramatically simplified its oxidative folding while preserving the peptide's ability to block voltage-gated sodium channels. The simplicity of synthesizing disulfide-depleted selenopeptide analogs containing a single disulfide bridge allowed rapid positional scanning at Lys7 of mu-KIIIA, resulting in the identification of K7L as a mutation that improved the peptide's selectivity in blocking a neuronal (Na(v)1.2) over a muscle (Na(v)1.4) subtype of sodium channel. The disulfide-depleted selenopeptide strategy offers regioselective folding compatible with high throughput chemical synthesis and on-resin oxidation methods, and thus shows great promise to accelerate the use of disulfide-rich peptides as research tools and drugs.
authors.affiliation: Departments of Biology, University of Utah, Salt Lake City, Utah, 84112, USA.
authors.forename: Tiffany S
authors.initials: TS
authors.lastname: Han
authors.forename: Min-Min
authors.initials: MM
authors.lastname: Zhang
authors.forename: Konkallu Hanumae
authors.initials: KH
authors.lastname: Gowd
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Walewska
authors.forename: Doju
authors.initials: D
authors.lastname: Yoshikami
authors.forename: Baldomero M
authors.initials: BM
authors.lastname: Olivera
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Bulaj