Solution structure of a defensin-like peptide from platypus venom.
Torres AM,
Wang X,
Fletcher JI,
Alewood D,
Alewood PF,
Smith R,
Simpson RJ,
Nicholson GM,
Sutherland SK,
Gallagher CH,
King GF,
Kuchel PW.
Department of Biochemistry, University of Sydney, NSW 2006, Australia.
Three defensin-like peptides (DLPs) were isolated from platypus venom and sequenced. One of these peptides, DLP-1, was synthesized chemically and its three-dimensional structure was determined using NMR spectroscopy. The main structural elements of this 42-residue peptide were an anti-parallel beta-sheet comprising residues 15-18 and 37-40 and a small 3(10) helix spanning residues 10-12. The overall three-dimensional fold is similar to that of beta-defensin-12, and similar to the sodium-channel neurotoxin ShI (Stichodactyla helianthus neurotoxin I). However, the side chains known to be functionally important in beta-defensin-12 and ShI are not conserved in DLP-1, suggesting that it has a different biological function. Consistent with this contention, we showed that DLP-1 possesses no anti-microbial properties and has no observable activity on rat dorsal-root-ganglion sodium-channel currents.
PMID: 10417345 [PubMed - indexed for MEDLINE]
PMCID: PMC1220419