An oxidative metabolic pathway of 4-deoxy-L-erythro-5-hexoseulose uronic acid (DEHU) from alginate in an alginate-assimilating bacterium.

Alginate-assimilating bacteria degrade alginate into an unsaturated monosaccharide, which is converted into 4-deoxy-L-erythro-5-hexoseulose uronic acid (DEHU). DEHU is reduced to 2-keto-3-deoxy-D-gluconate by a DEHU-specific reductase using NAD(P)H. This is followed by pyruvate production via the Entner-Doudoroff pathway.

Functional identification of the 4-deoxy-L-erythro-5-hexoseulose uronate reductase from a brown alga, Saccharina japonica.

We previously reported the alginate lyase, SjAly, from a brown alga, Saccharina japonica, providing the first experimental evidence for a functional alginate-degradation enzyme in brown algae. 4-deoxy-L-erythro-5-hexoseulose uronate (DEHU), derived from an unsaturated monosaccharide, was identified as the minimum degradation product produced by SjAly-mediated lysis of alginate. DEHU was hitherto reported to be reduced to 2-keto-3-deoxy-gluconate (KDG) by a DEHU-specific reductase with NAD(P)H in alginate-assimilating organisms and its metabolism in alginate-producing organisms is unknown.

Identification and characterization of cellouronate (β-1,4-linked polyglucuronic acid) lyase from the scallop Mizuhopecten yessoensis.

The semisynthetic polysaccharide cellouronate is a β-1,4-linked polyglucuronic acid prepared from regenerated cellulose by chemical oxidation. Here, we isolated a novel enzyme, MyAly, as a cellouronate lyase from a scallop Mizuhopecten yessoensis. Its optimum temperature, pH, and NaCl concentration for cellouronate degradation were determined to be 30 °C, 6.

Production of a novel dimeric 4-deoxy-L-erythro-5-hexoseulose uronic acid by a PL-17 exolytic alginate lyase from Hydrogenophaga sp. UMI-18.

Hydrogenopahaga sp. strain UMI-18 is an alginolytic bacterium that can produce poly(3-hydroxybutylate) (PHB) using alginate as its sole carbon source. Genome analysis indicated that this strain harbors both PHB-synthesizing and alginate-assimilating gene clusters.

Functional identification of alginate lyase from the brown alga Saccharina japonica.

Despite the progress in massive gene analysis of brown algal species, no alginate-degrading enzyme from brown alga has been identified, impeding the understanding of alginate metabolism in brown alga. In the current study, we identified and characterized alginate lyase from Saccharina japonica using a protein-based approach. First, cDNA library was prepared from the S.

Production of poly(3-hydroyxybutylate) by a novel alginolytic bacterium Hydrogenophaga sp. strain UMI-18 using alginate as a sole carbon source.

A novel alginolytic bacterium Hydrogenophaga sp. strain UMI-18 that produces poly(3-hydroyxybutylate) (PHB) in the alginate-mineral salt (AMS) medium containing 1% (w/v) sodium alginate as a sole carbon source was isolated from a decayed brown seaweed litter. The yield of PHB produced by strain UMI-18 was 1.

Polysaccharide-Degrading Enzymes From Marine Gastropods.

Seaweed polysaccharides have been widely used as viscosifier, gelling agents, and stabilizer in the various application fields, e.g., food, pharmaceutical, nutraceutical, and chemical industries.

Author Correction: Laminarinase from Flavobacterium sp. reveals the structural basis of thermostability and substrate specificity.

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Structural basis for controlling the enzymatic properties of polymannuronate preferred alginate lyase FlAlyA from the PL-7 family.

FlAlyA is an endolytic enzyme with a preference for polymannuronate. The crystal structure and mutagenesis studies elucidated that the structural variations at outer uronate-binding subsites +2, +3 and -2 control the enzymatic properties of PL-7 family enzymes. Lys158 mutations changed the pH dependency and enhanced the production of mono- and disaccharides.

Laminarinase from Flavobacterium sp. reveals the structural basis of thermostability and substrate specificity.

Laminarinase from Flavobacterium sp. strain UMI-01, a new member of the glycosyl hydrolase 16 family of a marine bacterium associated with seaweeds, mainly degrades β-1,3-glucosyl linkages of β-glucan (such as laminarin) through the hydrolysis of glycosidic bonds. We determined the crystal structure of ULam111 at 1.

Identification of 2-keto-3-deoxy-d-Gluconate Kinase and 2-keto-3-deoxy-d-Phosphogluconate Aldolase in an Alginate-Assimilating Bacterium, Flavobacterium sp. Strain UMI-01.

Recently, we identified an alginate-assimilating gene cluster in the genome of sp. strain UMI-01, a member of . Alginate lyase genes and a 4-deoxy-l-erythro-5-hexoseulose uronic acid (DEH) reductase gene in the cluster have already been characterized; however, 2-keto-3-deoxy-d-gluconate (KDG) kinase and 2-keto-3-deoxy-6-phosphogluconate (KDPG) aldolase genes, i.

F-fucoidan from Saccharina japonica is a novel inducer of galectin-9 and exhibits anti-allergic activity.

Fucoidan is a sulfated polysaccharide from brown sea algae. In the present study, it was demonstrated that oral administration of F-fucoidan from Saccharina japonica possessed anti-allergic effects using the passive cutaneous anaphylaxis reaction, but not by intraperitoneal administration. The inhibitory mechanism was dependent on galectin-9, which belongs to a soluble lectin family that recognizes β-galactoside and prevents IgE binding to mast cells.

Discovery of a Novel Alginate Lyase from Nitratiruptor sp. SB155-2 Thriving at Deep-sea Hydrothermal Vents and Identification of the Residues Responsible for Its Heat Stability.

Extremophiles are expected to represent a source of enzymes having unique functional properties. The hypothetical protein NIS_0185, termed NitAly in this study, was identified as an alginate lyase-homolog protein in the genomic database of ϵ-Proteobacteria Nitratiruptor sp. SB155-2, which was isolated from deep-sea hydrothermal vents at a water depth of 1,000 m.

A Novel Aldo-Keto Reductase, HdRed, from the Pacific Abalone Haliotis discus hannai, Which Reduces Alginate-derived 4-Deoxy-L-erythro-5-hexoseulose Uronic Acid to 2-Keto-3-deoxy-D-gluconate.

Abalone feeds on brown seaweeds and digests seaweeds' alginate with alginate lyases (EC 4.2.2.

Cellulose is not degraded in the tunic of the edible ascidian Halocynthia roretzi contracting soft tunic syndrome.

Soft tunic syndrome is a fatal disease in the edible ascidian Halocynthia roretzi, causing serious damage to ascidian aquaculture in Korea and Japan. In diseased individuals, the tunic, an integumentary extracellular matrix of ascidians, softens and eventually tears. This is an infectious disease caused by the kinetoplastid flagellate Azumiobodo hoyamushi.

Characterization of an Eukaryotic PL-7 Alginate Lyase in the Marine Red Alga .

Background: Alginate lyases belonging to polysaccharide lyase family-7 (PL-7) are the most well studied on their structures and functions among whole alginate lyases. However, all characterized PL-7 alginate lyases are from prokaryotic bacteria cells. Here we report the first identification of eukaryotic PL-7 alginate lyase from marine red alga Pyropia yezoensis.

The marine bacteria Cobetia marina DSMZ 4741 synthesizes an unexpected K-antigen-like exopolysaccharide.

We have studied the exopolysaccharide produced by Cobetia marina DSMZ 4741, a marine bacterium isolated from coastal seawater. This strain is able to produce a polysaccharide in presence of carbon sources as glucose, mannitol and alginate. The maximum production occurs in aerobic condition, during the end of the exponential phase.

Identification of a 4-deoxy-L-erythro-5-hexoseulose uronic acid reductase, FlRed, in an alginolytic bacterium Flavobacterium sp. strain UMI-01.

In alginate-assimilating bacteria, alginate is depolymerized to unsaturated monosaccharide by the actions of endolytic and exolytic alginate lyases (EC 4.2.2.

Characterization of an alginate lyase, FlAlyA, from Flavobacterium sp. strain UMI-01 and its expression in Escherichia coli.

A major alginate lyase, FlAlyA, was purified from the periplasmic fraction of an alginate-assimilating bacterium, Flavobacterium sp. strain UMI-01. FlAlyA showed a single band of ~30 kDa on SDS-PAGE and exhibited the optimal temperature and pH at 55 °C and pH 7.

Characterization of a GHF45 cellulase, AkEG21, from the common sea hare Aplysia kurodai.

The common sea hare Aplysia kurodai is known to be a good source for the enzymes degrading seaweed polysaccharides. Recently four cellulases, i.e.

A laminaribiose-hydrolyzing enzyme, AkLab, from the common sea hare Aplysia kurodai and its transglycosylation activity.

Endo-β-1,3-glucanases (laminarinase, EC 3.2.1.

Ca²+-binding properties and regulatory roles of lobster troponin C sites II and IV.

Invertebrate troponin C typically contains Ca²⁺-specific binding sites, sites II and IV, in the N- and C-terminal domains, respectively. To investigate the roles of these sites for Ca²⁺-dependent regulation of muscle contraction, we generated lobster troponin C mutants, and analyzed their Ca²⁺-binding properties and regulatory effects on actomyosin-tropomyosin Mg-ATPase activity. The results suggest that Ca²⁺ binding to site IV is responsible for regulation at relatively low Ca²⁺ concentrations, while site II has an essential role in full activation at higher Ca²⁺ concentrations.

Characterization of an α-glucosidase, HdAgl, from the digestive fluid of Haliotis discus hannai.

Previously, we isolated two α-amylase isozymes, HdAmy58 and HdAmy82, from the digestive fluid of the Pacific abalone Haliotis discus hannai (Kumagai et al., 2013, Comp. Biochem.

Modulation of platelet aggregation-related eicosanoid production by dietary F-fucoidan from brown alga Laminaria japonica in human subjects.

Laminaria japonica is traditionally eaten in Japan as a beneficial food for thrombosis. The alga contains two specific ingredients, a xanthophyll fucoxanthin (FX) and a polysaccharide, F-fucoidan (FD). The aim of the present study was to investigate whether FX or FD exhibited anti-thrombotic effects.