D-amino-acid residue in a defensin-like peptide from platypus venom: effect on structure and chromatographic properties
You are here
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]
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.
Repository Staff Only:
item control page