New Cyclotides Isolated from the Roots of Allexix batangae (Violaceae)

Cyclotides are a very abundant class of plant peptides that display significant sequence variability around a conserved cystine-knot motif and a head-to-tail cyclized backbone conferring them with remarkable stability. Their intrinsic bioactivities combined with tools of peptide engineering make cyclotides an interesting template for the design of novel agrochemicals and pharmaceuticals. In this work, we extend the knowledge about their sequence diversity by analysing the cyclotide content of a Violaceae specie native to Cameroon. Using an experimental approach, which was named sequence fragment assembly by MALDI-TOF/TOF, it was possible to characterize 4 cyclotides from the roots of Allexis batangeae . Amino acid sequencing of various enzymatic digests of cyclotides allowed the accurate assembly and alignment of smaller fragments to elucidate their primary structure.