Brown Alga Metabolites – Inhibitors of Marine Organism Fucoidan Hydrolases

Abstract

Fucoidan hydrolase inhibitors were discovered for the first time. Metabolites in the aqueous EtOH extract of Fucus evanescens inhibited specifically the activity of enzymes involved in catabolism of brown-alga polysaccharides, i.e., fucoidanases (recombinant FFA from the marine bacterium Formosa algae KMM 3553T and PPF from the marine mollusk Patinopecten yessoensis) and glycosidases (recombinant D-L-fucosidase FucFa from F. algae and E-D-glucosidase G-II from the marine mollusk Littorina sitkana). The purified fucophlorethol fraction isolated from this extract inhibited recombinant fucoidanase FFA in the concentration range 10-50 Pg/mL.Enzyme-catalyzed biochemical reactions are fundamental to in vivo metabolic processes. Enzyme inhibitors are very significant in pharmacology and toxicology and are used to study enzyme mechanisms of action and establish the active-site structures because of their high specificity.Carbohydrase inhibitors from natural sources have stimulated unwavering interest. Enzyme inhibitors in nature are known to act often as interspecies relationship regulators. For example, amylase inhibitors from grain sprouts are toxic for insects and mammals. Furthermore, amylase inhibitors were detected among so-called pathogen-responsive proteins (PR-proteins) involved in the plant protective mechanism. Amylases and glycosidases are the most studied natural inhibitors. Their effects on plant-insect relationships or forage animals are being actively studied [1,2].Brown algae, like terrestrial plants, protect themselves from predation by marine invertebrates or microorganisms by synthesizing alginate lyases, laminarinases, and fucoidanases. Reports of carbohydrase inhibitors from marine sources are very sparse [3,4], as for fucoidanase producers [5,6].We discovered several sources that biosynthesize active fucoidan hydrolases [7,8]. The role of these enzymes and; correspondingly, their inhibitors, is difficult to overestimate because all brown algae synthesize fucoidans. The total mass of these polysaccharides in nature is enormous and should be utilized in some manner.The goal of the present research was to seek fucoidan hydrolase inhibitors among metabolites of brown algae inhabiting the seas of the Russian Far East.Enzymes involved in brown alga polysaccharide catabolism were used to discover inhibitors. These were highly purified fucoidanases (recombinant FFA from the marine bacterium Formosa algae KMM 3553T [7] and PPF from the marine mollusk Patinopecten yessoensis [6]) and glycosidases (E-D-glucosidase G-II from the marine mollusk Littorina sitkana [9] and recombinant D-L-fucosidase FucFa from F. algae). Recombinant D-L-fucosidase FucFa was prepared especially for this research because it is involved in fucoidan catabolism. E-D-Glucosidase G-II, which catalyzes hydrolysis of laminarioligosaccharides and laminaran, was used to demonstrate the specificity of the discovered fucoidan hydrolase inhibitors. Fucoidan from Fucus evanescens was used as the substrate for the fucoidanases; p-Np-D-L-fuco-and ...

Ecological Function of Phenolic Compounds from Mediterranean Fucoid Algae and Seagrasses: An Overview on the Genus Cystoseira sensu lato and Posidonia oceanica (L.) Delile

“…Lamouroux, suggests that the last one invests more resources in defensive metabolites due to a higher grazer pressure [78] (Figure 4). Phlorotannins also induce resistance to grazing [99]. Induced resistance (increase of phlorotannins) decreases grazing pressure by deterring herbivores (grazed algae avoids future clipping from grazers which prefer ungrazed algae), as well as impairing their performance [100].…”

Effect of Phlorotannins from Brown Algae Costaria costata on α-N-Acetylgalactosaminidase Produced by Duodenal Adenocarcinoma and Melanoma Cells

“…The same fraction of CcPh irreversibly inactivated the recombinant enzyme endo-α-1,4- l -fucanase (EC 3.2.1.212) from the marine bacterium Formosa alga KMM 3553 T ( IC 50 = 39 μg/mL) [ 35 ]. Another fraction of phlorotannins from the brown algae F. evanescens inhibited recombinant endo-α-1,4-L-fucanase ( IC 50 = 22 μg/mL) [ 35 ] and α- l -fucosidase ( IC 50 = 29 μg/mL) from the marine bacterium Formosa alga KMM 3553 T , as well as a native endo-fucanase (in which the interval of inhibiting concentrations was 30–80 μg/mL) from the marine mollusk Patinopecten yessoensis and β-glucosidase ( IC 50 = 100 μg/mL) from the marine mollusk Littorina sitkata [ 39 ].…”