Synthesis, conformational analysis and biological properties of a dicarba derivative of the antimicrobial peptide, brevinin-1BYa

M Hossain, Laure Guilhaudis, Agnes Sonnevend, Samir Attoub, Bianca Van Lierop, Andrea Robinson, John Wade, J Michael Conlon

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23 Citations (Scopus)

Abstract

Brevinin-1BYa (FLPILASLAAKFGPKLFCLVTKKC), first isolated from skin secretions of the frog Rana boylii, displays broad-spectrum antimicrobial activity and potent haemolytic activity. This study investigates the effects on conformation and biological activity of replacement of the intramolecular disulphide bridge in the peptide by a non-reducible dicarba bond. Dicarba-brevinin-1BYa was prepared by microwave irradiation of [Agl(18),Agl(24)]-brevinin-1BYa (Agl = allylglycine) in the presence of a second generation Grubbs catalyst. Circular dichroism spectroscopy in 50 trifluoroethanol-water indicated that the degree of alpha-helicity of the dicarba derivative (22 ) was less than that of brevinin-1BYa (27 ) but comparable to that of the acyclic derivative [Ser(18),Ser(24)]-brevinin-1BYa (23 ). Dicarba-brevinin-1BYa showed a two-fold increase in potency against reference strains of Escherichia coli, Staphylococcus aureus, and Candida albicans compared with the native peptide and displayed potent bactericidal activity against clinical isolates of methicillin-resistant S. aureus (MRSA) and multidrug-resistant Acinetobacter baumannii (MIC in the range 1-8 mu M). Compared with brevinin-1BYa and [Ser(18),Ser(24)]-brevinin-1BYa, the dicarba derivative was associated with increased cytotoxicity against human erythrocytes (2.5-fold), MDA-MB-231 breast carcinoma cells (1.3-fold) and HepG2 hepatoma-derived cells (1.5-fold).
Original languageEnglish
Pages (from-to)555 - 564
Number of pages10
JournalEuropean Biophysics Journal
Volume40
Issue number4
DOIs
Publication statusPublished - 2011

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