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D-amino-acid residue in a defensin-like peptide from platypus venom: effect on structure and chromatographic properties


Torres, AM and Tsampazi, C and Geraghty, DP and Bansal, PS and Alewood, PF and Kuchel, PW, D-amino-acid residue in a defensin-like peptide from platypus venom: effect on structure and chromatographic properties, Biochemical Journal, 391, (2) pp. 215-220. ISSN 0264-6021 (2005) [Refereed Article]

DOI: doi:10.1042/BJ20050900


The recent discovery that the natriuretic peptide OvCNPb (Ornithorhynchus venom C-type natriuretic peptide B) from platypus (Ornithorynchus anatinus) venom contains a D-amino acid residue suggested that other D-amino-acid- containing peptides might be present in the venom. In the present study, we show that DLP-2 (defensin-like peptide-2), a 42-amino-acid residue polypeptide in the platypus venom, also contains a D-amino acid residue, D-methionine, at position 2, while DLP-4, which has an identical amino acid sequence, has all amino acids in the L-form. These findings were supported further by the detection of isomerase activity in the platypus gland venom extract that converts DLP-4 into DLP-2. In the light of this new information, the tertiary structure of DLP-2 was recalculated using a new structural template with D-Met2. The structure of DLP-4 was also determined in order to evaluate the effect of a D-amino acid at position 2 on the structure and possibly to explain the large retention time difference observed for the two molecules in reverse-phase HPLC. The solution structures of the DLP-2 and DLP-4 are very similar to each other and to the earlier reported structure of DLP-2, which assumed that all amino acids were in the L-form. Our results suggest that the incorporation of the D-amino acid at position 2 has minimal effect on the overall fold in solution. © 2005 Biochemical Society.

Item Details

Item Type:Refereed Article
Research Division:Biomedical and Clinical Sciences
Research Group:Medical biochemistry and metabolomics
Research Field:Medical biochemistry - proteins and peptides (incl. medical proteomics)
Objective Division:Environmental Management
Objective Group:Terrestrial systems and management
Objective Field:Terrestrial biodiversity
UTAS Author:Geraghty, DP (Professor Dominic Geraghty)
ID Code:34091
Year Published:2005
Web of Science® Times Cited:48
Deposited By:Health Sciences A
Deposited On:2005-08-01
Last Modified:2012-03-05

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