Anabaenopeptins: What We Know So Far

Abstract

Cyanobacteria are microorganisms with photosynthetic mechanisms capable of colonizing several distinct environments worldwide. They can produce a vast spectrum of bioactive compounds with different properties, resulting in an improved adaptative capacity. Their richness in secondary metabolites is related to their unique and diverse metabolic apparatus, such as Non-Ribosomal Peptide Synthetases (NRPSs). One important class of peptides produced by the non-ribosomal pathway is anabaenopeptins. These cyclic hexapeptides demonstrated inhibitory activity towards phosphatases and proteases, which could be related to their toxicity and adaptiveness against zooplankters and crustaceans. Thus, this review aims to identify key features related to anabaenopeptins, including the diversity of their structure, occurrence, the biosynthetic steps for their production, ecological roles, and biotechnological applications.

Insights into the Antimicrobial Activities and Metabolomes of Aquimarina (Flavobacteriaceae, Bacteroidetes) Species from the Rare Marine Biosphere

“…These may be examples of ‘silent’ SM-BGCs, a hypothesis that could be explored in the future by testing different culture conditions and extraction methods. Moreover, the anabaenopeptin NZ857 SM-BGC of A. muelleri may have been acquired by horizontal gene transfer, since anabaenopeptins are typically found in Cyanobacteria [ 67 , 68 ].…”

“…Moreover, we detected cuniculene in the Aq78 extracts but not in the Aq349, EL33 and A. muelleri extracts, although we found the four strains to harbor the trans-AT PKS SM-BGC that encodes cuniculene. Similarly, although not identified in its SPE extracts, A. muelleri possessed a singleton NRPS cluster with 100% similarity to that encoding for anabaenopeptin NZ857 (nostamide A), a highly toxic compound known for its inhibitory activity of proteases, phosphatases, and carboxypeptidases [67]. These may be examples of 'silent' SM-BGCs, a hypothesis that could be explored in the future by testing different culture conditions and extraction methods.…”

Anabaenopeptins from Cyanobacteria in Freshwater Bodies of Greece

“…Additionally, AP A, AP B and AP F have had toxicity effects in the nematode Caenorhabditis elegans [70]. Even though APs toxicity effects on animal models and microorganisms have been reported, there remains a lack of data regarding their toxicity and impact on human health [12].…”

“…The proposed side chain of the three novel consists of infrequent amino acids (i.e., Lys and OEtGlu). Lys (AP 894) has been d mined in the side chain of six known congeners (Figure 1, Table S1), while OEtGlu Specifically, the currently known 42 APs from freshwater environments mainly consist of Val (45%) and Ile (29%) in position X 3 , Hty (64%) and Hph (29%) in position X 4 , MeAla (50%) and MeHty (38%) in position X 5 and Phe (45%) and Ile (24%) in position X 6 [12]. The 13 APs identified in Greek freshwaters consist of Val (38%) and Ile (62%) in position X 3 , Hty (69%) and Hph (31%) in position X 4 , MeAla (85%) and MeHty (15%) in position X 5 and Phe (85%) and Ile (15%) in position X 6 (Figure 5).…”

“…The presence of APs has been reported in freshwater [2][3][4][5][6] and marine cyanobacterial blooms [7][8][9], as well as in terrestrial environments, including the leaves of plants in a coastal forest [10] and the terrestrial mat in a bamboo forest [11]. APs are produced by freshwater, marine and terrestrial cyanobacteria [12] mainly belonging to the genera Planktothrix [13,14], Anabaena [15][16][17][18], Microcystis [19][20][21][22][23] and Nostoc [24,25]. They especially belong to the species Planktothrix (Oscillatoria) agardhii [3,[26][27][28][29][30][31][32], Planktothrix rubescens [30,31,33,34], Anabaena (Dolichospermum) flos-aquae [35], Anabaena lemmermannii [36], Microcystis aeruginosa [3,[37][38][39], Microcystis flos-aquae [36], Microcystis ichthyoblabe, Microcystis wesenbergii [19] and Nostoc punctiforme [40], as we...…”