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Publication Abstract from PubMed

Design of clinically valuable antibacterial agents based upon naturally occurring peptides requires the use of spectroscopic methods, particularly NMR, to determine the three-dimensional structure of the native peptide so that analogues with improved therapeutic properties can be made. Ranatuerin-2CSa (GILSSFKGVAKGVAKDLAG KLLETLKCKITGC), first isolated from skin secretions of the Cascades frog, Rana cascadae, represents a promising candidate for drug development. The peptide shows potent growth inhibitory activity against Escherichia coli (MIC=5 muM) and Staphylococcus aureus (MIC=10 muM) but displays haemolytic activity against human erythrocytes (LC(50)=160 muM). The solution structure of ranatuerin-2CSa was investigated by proton NMR spectroscopy and molecular modelling. In aqueous solution, the peptide lacks secondary structure but, in a 2,2,2-trifluoroethanol (TFE-d(3))-H(2)O solvent mixture, the structure is characterised by a full length helix-turn-helix conformation between residues I(2)-L(21), L(22)-L(25) and K(26)-T(30) respectively. This structural information will facilitate the design of novel therapeutic agents based upon the ranatuerin-2CSa structure with improved antimicrobial potencies but decreased cytolytic activities against mammalian cells.

Conformational analysis of the broad-spectrum antibacterial peptide, ranatuerin-2CSa: Identification of a full length helix-turn-helix motif.,Subasinghage AP, Conlon JM, Hewage CM Biochim Biophys Acta. 2008 Jun;1784(6):924-9. Epub 2008 Mar 14. PMID:18387372^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.