Design, structural and functional characterization of a Temporin-1b analog active against Gram-negative bacteria(942 views) Avitabile C, Netti F, Orefice G, Palmieri M, Nocerino N, Malgieri G, D'Andrea LD, Capparelli R, Fattorusso R, Romanelli A
Università di Napoli Federico II, Dipartimento Delle Scienze Biologiche, Via Mezzocannone 16, 80134 Napoli, Italy
Seconda Università Degli Studi di Napoli, Dipartimento di Scienze Ambientali, Via Vivaldi 43, 81100 Caserta, Italy
Istituto di Biostrutture e Bioimmagini (CNR), Via Mezzocannone 16, 80134 Napoli, Italy
Universit di Napoli Federico II, Dipartimento Delle Scienze Biologiche, Via Mezzocannone 16, 80134 Napoli, Italy
Seconda Universit Degli Studi di Napoli, Dipartimento di Scienze Ambientali, Via Vivaldi 43, 81100 Caserta, Italy
References: Not available.
Design, structural and functional characterization of a Temporin-1b analog active against Gram-negative bacteria
Background: Temporins are small antimicrobial peptides secreted by the Rana temporaria showing mainly activity against Gram-positive bacteria. However, different members of the temporin family, such as Temporin B, act in synergy also against Gram-negative bacteria. With the aim to develop a peptide with a wide spectrum of antimicrobial activity we designed and analyzed a series of Temporin B analogs. Methods: Peptides were initially obtained by Ala scanning on Temporin B sequence; antimicrobial activity tests allowed to identify the TB_G6A sequence, which was further optimized by increasing the peptide positive charge (TB_KKG6A). Interactions of this active peptide with the LPS of E. coli were investigated by CD, fluorescence and NMR. Results: TB_KKG6A is active against Gram-positive and Gram-negative bacteria at low concentrations. The peptide strongly interacts with the LPS of Gram-negative bacteria and folds upon interaction into a kinked helix. Conclusion: Our results show that it is possible to widen the activity spectrum of an antimicrobial peptide by subtle changes of the primary structure. TB_KKG6A, having a simple composition, a broad spectrum of antimicrobial activity and a very low hemolytic activity, is a promising candidate for the design of novel antimicrobial peptides. General significance: The activity of antimicrobial peptides is strongly related to the ability of the peptide to interact and break the bacterial membrane. Our studies on TB_KKG6A indicate that efficient interactions with LPS can be achieved when the peptide is not perfectly amphipathic, since this feature seems to help the toroidal pore formation process. (C) 2013 Elsevier B.V. All rights reserved.
Design, structural and functional characterization of a Temporin-1b analog active against Gram-negative bacteria