Chemically labeled toxins or bioactive peptides show a heterogeneous intracellular distribution and low spatial overlap with autofluorescence in bloom-forming cyanobacteria.

ABSTRACT: Harmful algal blooms formed by colony-forming cyanobacteria deteriorate water resources by producing cyanotoxins, which frequently occur at high intracellular concentrations. We aimed to localize toxic microcystins (MCs) and bioactive anabaenopeptins (APs) at the subcellular level under noninvasive conditions. Since both metabolites are synthesized nonribosomally, the relaxed specificity of key enzymes catalyzing substrate activation allowed chemical labeling through a standard copper-catalyzed click chemistry reaction. The genera Planktothrix and Microcystis specifically incorporated unnatural amino acids such as N-propargyloxy-carbonyl-L-lysine or O-propargyl-L-tyrosine, resulting in modified AP or MC peptides carrying the incorporated alkyne moiety. The labeled cells were quantitatively

SUBMITTER: Kurmayer R 

PROVIDER: S-EPMC7026079 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature