7p4x
From Proteopedia
SOLUTION NMR STRUCTURE OF PALUSTRIN-CA IN 50% TRIFLUOROETHANOL
Structural highlights
FunctionPACA_LITCT Antibacterial peptide with amphipathic alpha-helical structure that exhibits potent broad-spectrum activity against Gram-positive and -negative bacteria (Ref.1, PubMed:34789753). It is active against Listeria ATCC 54004 (MIC=30 ug/ml), S.aureus ATCC 25923 (MIC=7.8 ug/ml), S.suis 2 CVCC 606 (MIC=31.25 ug/ml), B.subtilis ADB403 (30 ug/ml), K.pneumoniae ATCC 700603 (MIC=60 ug/ml) and P. aeruginosa ATCC 227853 (MIC=30 ug/ml) (Ref.1). Does not show activity against Salmonella ATCC 20020 and the fungus Candida albicans (Ref.1). Is also cytotoxic to HeLa cells at high concentrations (Ref.1). In addition, shows a strong antitumor activity but only a little hemolytic activity (Ref.1). Despite the presence of a Gly residue at position 10, this alpha-helical peptide remains relatively rigid, not exhibiting any significant flexibility during the molecular dynamics simulation (PubMed:34789753). The peptide shows a preference for a position parallel to the target membrane that suggests it exerts its antimicrobial activity through a non-pore-forming mechanism of action, such as the carpet model or the interfacial activity model (PubMed:34789753).[1] [REFERENCE:1] Publication Abstract from PubMedPalustrin-Ca (GFLDIIKDTGKEFAVKILNNLKCKLAGGCPP) is a host defence peptide with potent antimicrobial and anticancer activities, first isolated from the skin of the American bullfrog Lithobates catesbeianus. The peptide is 31 amino acid residues long, cationic and amphipathic. Two-dimensional NMR spectroscopy was employed to characterise its three-dimensional structure in a 50/50% water/2,2,2-trifluoroethanol-[Formula: see text] mixture. The structure is defined by an [Formula: see text]-helix that spans between Ile[Formula: see text]-Ala[Formula: see text], and a cyclic disulfide-bridged domain at the C-terminal end of the peptide sequence, between residues 23 and 29. A molecular dynamics simulation was employed to model the peptide's interactions with sodium dodecyl sulfate micelles, a widely used bacterial membrane-mimicking environment. Throughout the simulation, the peptide was found to maintain its [Formula: see text]-helical conformation between residues Ile[Formula: see text]-Ala[Formula: see text], while adopting a position parallel to the surface to micelle, which is energetically-favourable due to many hydrophobic and electrostatic contacts with the micelle. Conformation and membrane interaction studies of the potent antimicrobial and anticancer peptide palustrin-Ca.,Timmons PB, Hewage CM Sci Rep. 2021 Nov 17;11(1):22468. doi: 10.1038/s41598-021-01769-3. PMID:34789753[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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