title: Two short D-Phe-containing cysteine-free conopeptides from Conus marmoreus.
abstract: The cysteine-free conopeptides are naturally occurring components of the venom of cone snails and have been relatively less investigated than the cysteine-containing conopeptides. In this work, we used thiol-exchange chromatography to isolate cysteine-free conopeptides from the venom of Conus marmoreus. The full-length previously reported conomarphin and two novel shortened forms of it were found in the cysteine-free conopeptide fraction. The two shortened conomarphins also contain a D-Phe and a hydroxylated proline residue, suggesting complex post-translational modifications of these conopeptides. In particular, the shorter conomarphin fragment shares significant sequence similarity with conophans. This work demonstrated that thiol-exchange chromatography is a useful approach to isolate cysteine-free conopeptides from venom cocktail. The newly identified conopeptides further revealed the complexity of post-translational processing and the high diversity of conotoxins.
authors.affiliation: Institute of Protein Research, Tongji University, Shanghai, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Shao
authors.forename: Chengwu
authors.initials: C
authors.lastname: Chi
authors.forename: Chunguang
authors.initials: C
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D020916:Conotoxins / Q000737:chemistry* / Q000235:genetics; D052078:Conus Snail / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000235:genetics; D010649:Phenylalanine / Q000737:chemistry* / Q000235:genetics
chemical_list: D020916:Conotoxins; D010455:Peptides; D010649:Phenylalanine; D003545:Cysteine