PMID: 26509914

Authors:

Boldbaatar D, Gunasekera S, El-Seedi HR, Goransson U

Title:

Synthesis, Structural Characterization, and Bioactivity of the Stable Peptide RCB-1 from Ricinus communis.

Journal:

J Nat Prod. 2015 Nov 25;78(11):2545-51. doi: 10.1021/acs.jnatprod.5b00463. Epub, 2015 Oct 28.

Abstract:

The Ricinus communis biomarker peptides RCB-1 to -3 comprise homologous sequences of 19 (RCB-1) or 18 (RCB-2 and -3) amino acid residues. They all include four cysteine moieties, which form two disulfide bonds. However, neither the 3D structure nor the biological activity of any of these peptides is known. The synthesis of RCB-1, using microwave-assisted, Fmoc-based solid-phase peptide synthesis, and a method for its oxidative folding are reported. The tertiary structure of RCB-1, subsequently established using solution-state NMR, reveals a twisted loop fold with antiparallel beta-sheets reinforced by the two disulfide bonds. Moreover, RCB-1 was tested for antibacterial, antifungal, and cytotoxic activity, as well as in a serum stability assay, in which it proved to be remarkably stable.