Journal article

Structure and sodium channel activity of an excitatory I-1-superfamily conotoxin

Olga Buczek, Daxiu Wei, Jeffrey J Babon, Xiaodong Yang, Brian Fiedler, Ping Chen, Doju Yoshikami, Baldomero M Olivera, Grzegorz Bulaj, Raymond S Norton

Biochemistry | AMER CHEMICAL SOC | Published : 2007

Abstract

Conotoxin iota-RXIA, from the fish-hunting species Conus radiatus, is a member of the recently characterized I1-superfamily, which contains eight cysteine residues arranged in a -C-C-CC-CC-C-C- pattern. iota-RXIA (formerly designated r11a) is one of three characterized I1 peptides in which the third last residue is posttranslationally isomerized to the d configuration. Naturally occurring iota-RXIA with d-Phe44 is significantly more active as an excitotoxin than the l-Phe analogue both in vitro and in vivo. We have determined the solution structures of both forms by NMR spectroscopy, the first for an I1-superfamily member. The disulfide connectivities were determined from structure calculati..

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University of Melbourne Researchers