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Title: Heterologous expression and solution structure of defensin from lentil Lens culinaris

Journal Article · · Biochemical and Biophysical Research Communications
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  1. Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Str., 16/10, 117997 Moscow (Russian Federation)

Highlights: • Lentil defensin Lc-def and its {sup 15}N-labeled analog were overexpressed in E. coli. • Lc-def is active against fungi, but does not inhibit growth of G+ and G− bacteria. • Lc-def spatial structure involves triple-stranded β-sheet and α-helix (CSαβ motif). • Lc-def is able to bind to anionic lipid vesicles under low-salt conditions. • NMR data revealed significant μs–ms mobility in the loops 1 and 3 of Lc-def. - Abstract: A new defensin Lc-def, isolated from germinated seeds of the lentil Lens culinaris, has molecular mass 5440.4 Da and consists of 47 amino acid residues. Lc-def and its {sup 15}N-labeled analog were overexpressed in Escherichia coli. Antimicrobial activity of the recombinant protein was examined, and its spatial structure, dynamics, and interaction with lipid vesicles were studied by NMR spectroscopy. It was shown that Lc-def is active against fungi, but does not inhibit the growth of Gram-positive and Gram-negative bacteria. The peptide is monomeric in aqueous solution and contains one α-helix and triple-stranded β-sheet, which form cysteine-stabilized αβ motif (CSαβ) previously found in other plant defensins. The sterically neighboring loop1 and loop3 protrude from the defensin core and demonstrate significant mobility on the μs–ms timescale. Lc-def does not bind to the zwitterionic lipid (POPC) vesicles but interacts with the partially anionic (POPC/DOPG, 7:3) membranes under low-salt conditions. The Lc-def antifungal activity might be mediated through electrostatic interaction with anionic lipid components of fungal membranes.

OSTI ID:
22416718
Journal Information:
Biochemical and Biophysical Research Communications, Vol. 451, Issue 2; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
Country of Publication:
United States
Language:
English