Lysine-scanning mutagenesis reveals an amendable face of the cyclotide kalata B1 for the optimization of nematocidal activity.

ABSTRACT: Cyclotides are a family of macrocyclic peptides that combine the unique features of a head-to-tail cyclic backbone and a cystine knot motif, the combination of which imparts them with extraordinary stability. The prototypic cyclotide kalata B1 is toxic against two economically important gastrointestinal nematode parasites of sheep, Haemonchus contortus and Trichostrongylus colubriformis. A lysine scan was conducted to examine the effect of the incorporation of positive charges into the kalata B1 cyclotide framework. Each of the non-cysteine residues in this 29-amino acid peptide was successively substituted with lysine, and the nematocidal and hemolytic activities of the suite of mutants were determined. Substitution of 11 residues within kalata B1 decreased the nematocidal activity dramat

SUBMITTER: Huang YH 

PROVIDER: S-EPMC2856286 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature