Optimization of oxidative folding methods for cysteine-rich peptides: a study of conotoxins containing three disulfide bridges.
The oxidative folding of small, cysteine-rich peptides to selectively achieve the native disulfide bond connectivities is critical for discovery and structure-function studies of many bioactive peptides. As the propensity to acquire the native conformation greatly depends on the peptide sequence, numerous empirical oxidation methods are employed. The context-dependent optimization of these methods has thus far precluded a generalized oxidative folding protocol, in particular for peptides containing more than two disulfides. Herein, we compare the efficacy of optimized solution-phase and polymer-supported oxidation methods using three disulfide-bridged conotoxins, namely µ-SIIIA, µ-KIIIA and ω-GVIA. The use of diselenide bridges as proxies for disulfide bridges is also evaluated. We propose the ClearOx-assisted oxidation of selenopeptides as a fairly generalized oxidative folding protocol.
Steiner
Andrew M
AM
Department of Medicinal Chemistry, University of Utah, Salt Lake City, UT 84108, USA.
Bulaj
Grzegorz
G
D000595:Amino Acid Sequence; D000818:Animals; D019411:Clinical Laboratory Techniques; D020916:Conotoxins / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry*; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000737:chemistry; D010084:Oxidation-Reduction; D010455:Peptides / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D017510:Protein Folding; D012996:Solutions / Q000737:chemistry
D020916:Conotoxins; D009498:Neurotoxins; D010455:Peptides; D011108:Polymers; D012996:Solutions; D003545:Cysteine