2g9p
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /><applet load="2g9p" size="450" color="white" frame="true" align="right" spinBox="true" caption="2g9p" /> '''NMR structure of a novel antimicrobial pepti...)
Next diff →
Revision as of 08:56, 21 November 2007
|
NMR structure of a novel antimicrobial peptide, latarcin 2a, from spider (Lachesana tarabaevi) venom
Overview
Latarcins (Ltc), linear peptides (ca. 25 amino acid long) isolated from, the venom of the Lachesana tarabaevi spider, exhibit a broad-spectrum, antibacterial activity, most likely acting on the bacterial plasmatic, membrane. We study the structure-activity relationships in the series of, these compounds. At the first stage, we investigated the spatial structure, of one of the peptides, Ltc2a, and its mode of membrane perturbation. This, was done by a combination of experimental and theoretical methods. The, approach includes (i) structural study of the peptide by CD spectroscopy, in phospholipid liposomes and by (1)H NMR in detergent micelles, (ii), determination of the effect on the liposomes by a dye leakage fluorescent, assay and (31)P NMR spectroscopy, (iii) refinement of the NMR-derived, spatial structure via Monte Carlo simulations in an implicit water-octanol, slab, and (iv) calculation of the molecular hydrophobicity potential. The, molecule of Ltc2a was found to consist of two helical regions (residues, 3-9 and 13-21) connected via a poorly ordered fragment. The effect of the, peptide on the liposomes suggests the carpet mechanism of the membrane, deterioration. This is also supported by the analysis of, hydrophobic/hydrophilic characteristics of Ltc2a and homologous, antimicrobial peptides. These peptides exhibiting a helix-hinge-helix, structural motif are characterized by a distinct and feebly marked, amphiphilicity of their N- and C-terminal helices, respectively, and by a, hydrophobicity gradient along the peptide chain. The approach we suggested, may be useful in studying not only other latarcins but also a wider class, of membrane-active peptides.
About this Structure
2G9P is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Spatial structure and activity mechanism of a novel spider antimicrobial peptide., Dubovskii PV, Volynsky PE, Polyansky AA, Chupin VV, Efremov RG, Arseniev AS, Biochemistry. 2006 Sep 5;45(35):10759-67. PMID:16939228
Page seeded by OCA on Wed Nov 21 11:03:41 2007
