Glycosidase- and β-lactamase-like activity of dinuclear copper(II) patellamide complexes

Prochloron, a blue-green algae belonging to ancient prokaryotes, produces, like other cyanobacteria, cyclic pseudo-peptides, which are also found in its obligate symbiont ascidiae (Lissoclinum patellum). Although research has focused for some time on the putative metabolic function of these cyclic peptides, to date it is still not understood. Their role might be connected to the increased concentrations of divalent metal ions, especially CuII, found in ascidiae. Dinuclear copper(II) complexes of cyclic pseudo-peptides revealed a broad hydrolytic capacity, including carboanhydrase and phosphatase activity. This study reports their β-lactamase as well as α- and β-glycosidase activity with kcat=(11.34±0.91)ˑ10−4s−1 for β-lactamase, kcat=(1.55±0.13)ˑ10−4s−1 for α-glycosidase and kcat=(1.22±0.09)ˑ10−4s−1 for β-glycosidase activity. The dicopper(II) complexes of two cyclic pseudo-octapeptide ligands are shown to be models for Glycosidase and β-Lactamase enzymes. This adds to the broad spectrum of hydrolase activity of these derivatives of natural products and establishes a rare example of a glycosidase model system based on a dinuclear copper(II) complex. [Display omitted] •CuII-based glycosidase and β-lactamase are possible biological functions of the natural patellamides.•The dicopper(II) complexes are a rare example of CuII-based glycosidase mimics.•The configuration of the side chains of the cyclic peptides influences the catalytic reactivity.