Effect of enzyme preparation from the marine mollusk Littorina kurila on fucoidan from the brown alga Fucus distichus

The Endo-α(1,3)-Fucoidanase Mef2 Releases Uniquely Branched Oligosaccharides from Saccharina latissima Fucoidans

Fucoidans are complex bioactive sulfated fucosyl-polysaccharides primarily found in brown macroalgae. Endo-fucoidanases catalyze the specific hydrolysis of α-L-fucosyl linkages in fucoidans and can be utilized to tailor-make fucoidan oligosaccharides and elucidate new structural details of fucoidans. In this study, an endo-α(1,3)-fucoidanase encoding gene, Mef2, from the marine bacterium Muricauda eckloniae, was cloned, and the Mef2 protein was functionally characterized. Based on the primary sequence, Mef2 was suggested to belong to the glycosyl hydrolase family 107 (GH107) in the Carbohydrate Active enZyme database (CAZy). The Mef2 fucoidanase showed maximal activity at pH 8 and 35 °C, although it could tolerate temperatures up to 50 °C. Ca2+ was shown to increase the melting temperature from 38 to 44 °C and was furthermore required for optimal activity of Mef2. The substrate specificity of Mef2 was investigated, and Fourier transform infrared spectroscopy (FTIR) was used to determine the enzymatic activity (Units per μM enzyme: Uf/μM) of Mef2 on two structurally different fucoidans, showing an activity of 1.2 × 10-3 Uf/μM and 3.6 × 10-3 Uf/μM on fucoidans from Fucus evanescens and Saccharina latissima, respectively. Interestingly, Mef2 was identified as the first described fucoidanase active on fucoidans from S. latissima. The fucoidan oligosaccharides released by Mef2 consisted of a backbone of α(1,3)-linked fucosyl residues with unique and novel α(1,4)-linked fucosyl branches, not previously identified in fucoidans from S. latissima.

Overexpression and biochemical characterization of a truncated endo-α (1 → 3)-fucoidanase from alteromonas sp. SN-1009

Endo-fucoidanases are important in structural analysis of fucoidans and preparation of fuco-oligosaccharides. However their enzymological properties and analysis of degradation products are scarcely investigated. Truncated endo-α (1 → 3)-fucoidanase Fda1 (tFda1B from Alteromonas sp. was overexpressed and characterized, showing highest activity at pH 7.0, 35 °C, and 1.0 M NaCl. Its Km and kcat were 3.88 ± 0.81 mg/mL and 0.82 ± 0.17 min-1. Fe3+ and Mn2+ enhanced activity by 100% and 19.5% respectively. Co2+ and Cu2+ completely inactivated tFda1B, whereas Ni2+, Mg2+, Zn2+, Pb2+, Ca2+, Ba2+ and Li+ decreased activity by 58.8%, 56.0%, 50.6%, 47.7%, 28.9%, 15.6% and 37.5%, respectively. Catalytic residues were identified through structure and sequence alignment, and confirmed by mutagenesis. Degradation products of Kjellmaniella crassifolia fucoidan by tFda1B were characterized by LC-ESI-MS/MS, confirming tFda1B belongs to endo-(1 → 3)-fucoidanases, and backbone of K. crassifolia fucoidan is 1 → 3 fucoside linkage. This endo-α (1 → 3)-fucoidanase would be useful for elucidating fucoidan structures, and be used as a food enzyme.

Characterization of recombinant E. coli expressing a novel fucosidase from Bacillus cereus 2-8 belonging to GH95 family

Fucoidan oligosaccharides possesses diverse physicochemical and biological activities. Specific glycoside hydrolases are valuable tools for degrading polysaccharides to produce oligosaccharides. In this study, BcFucA, a novel fucosidase belonging to GH95 family from Bacillus cereus 2-8, was cloned into pET21a vector, expressed in E. coli BL21 (DE3) and characterized. The protein consists of 1136 amino acid residues encoded by 3411 bases and has a molecular weight of 125.35 kDa. The optimal temperature and pH of this enzyme are 50 °C and pH 4.0. In addition, this study showed that the unknown function domain (encoding Lys261-Thr681) defined as a linker is quite important for its activity. The obtained novel enzyme BcFucA will contribute to the effective degradation of fucoidan and future industrial applications.

Fucoidan Characterization: Determination of Purity and Physicochemical and Chemical Properties

Fucoidans are marine sulfated biopolysaccharides that have heterogenous and complicated chemical structures. Various sugar monomers, glycosidic linkages, molecular masses, branching sites, and sulfate ester pattern and content are involved within their backbones. Additionally, sources, downstream processes, and geographical and seasonal factors show potential effects on fucoidan structural characteristics. These characteristics are documented to be highly related to fucoidan potential activities. Therefore, numerous chemical qualitative and quantitative determinations and structural elucidation methods are conducted to characterize fucoidans regarding their physicochemical and chemical features. Characterization of fucoidan polymers is considered a bottleneck for further biological and industrial applications. Consequently, the obtained results may be related to different activities, which could be improved afterward by further functional modifications. The current article highlights the different spectrometric and nonspectrometric methods applied for the characterization of native fucoidans, including degree of purity, sugar monomeric composition, sulfation pattern and content, molecular mass, and glycosidic linkages.

Fucoidans: Downstream Processes and Recent Applications

Fucoidans are multifunctional marine macromolecules that are subjected to numerous and various downstream processes during their production. These processes were considered the most important abiotic factors affecting fucoidan chemical skeletons, quality, physicochemical properties, biological properties and industrial applications. Since a universal protocol for fucoidans production has not been established yet, all the currently used processes were presented and justified. The current article complements our previous articles in the fucoidans field, provides an updated overview regarding the different downstream processes, including pre-treatment, extraction, purification and enzymatic modification processes, and shows the recent non-traditional applications of fucoidans in relation to their characters.

Anti-Photoaging Effects of Low Molecular-Weight Fucoidan on Ultraviolet B-Irradiated Mice

Ultraviolet (UV) B exposure induces DNA damage and production of reactive oxygen species (ROS), which causes skin photoaging through signaling pathways of inflammation and modulation of extracellular matrix remodeling proteins, collagens, and matrix metalloproteinase (MMP). As low molecular-weight fucoidan (LMF) has potential antioxidant and anti-inflammatory properties, we examined the protective effects of LMF against UVB-induced photoaging. A UVB-irradiated mouse model was topically treated with myricetin or LMF at 2.0, 1.0 and 0.2 mg/cm² (LMF2.0, LMF1.0 and LMF0.2, respectively) once a day for 15 weeks. Wrinkle formation, inflammation, oxidative stress, MMP expression, and apoptosis in the treated regions were compared with those in a distilled water-treated photoaging model (UVB control). LMF treatments, particularly LMF2.0 and LMF1.0, significantly inhibited the wrinkle formation, skin edema, and neutrophil recruitment into the photo-damaged lesions, compared with those in the UVB control. While LMF decreased interleukin (IL)-1β release, it increased IL-10. The LMF treatment inhibited the oxidative stresses (malondialdehyde and superoxide anion) and enhanced endogenous antioxidants (glutathione). Additionally, LMF reduced the mRNA expression of MMP-1, 9, and 13. The histopathological analyses revealed the anti-photoaging effects of LMF exerted via its antioxidant, anti-apoptotic, and MMP-9-inhibiting effects. These suggest that LMF can be used as a skin-protective remedy for photoaging.

Modification of native fucoidan from Fucus evanescens by recombinant fucoidanase from marine bacteria Formosa algae

Enzymatic depolymerization of fucoidans attracts many researchers due to the opportunity of obtaining standardized fucoidan fragments. Fucoidanase catalyzes the cleavage of fucoidan from Fucus evanescens (FeF) to form low molecular weight products (LMP) and a polymeric fraction (HMP) with 50.8 kDa molecular weight and more than 50% yield. NMR spectroscopy shows that the HMP fraction has regular structure and consists of a repeating fragment [→3)-α-l-Fucp2,4OSO3--(1 → 4)-α-l-Fucp2,4OSO3--(1 → 4)-α-l-Fucp2OSO3--(1→]n. The anticancer effects of FeF fucoidan and its derivative (HMP) were studied in vitro on colon cancer cells HCT-116, HT-29, and DLD-1. The anticancer activity of the HMP fraction was found to be slightly lower than that of the FeF fucoidan. Research and practical applications of the enzyme include modification of native fucoidans for purposes of regular and easier characterized derivatives acquisition.

Expression and biochemical characterization and substrate specificity of the fucoidanase from Formosa algae

A gene that encodes fucoidanase ffa2 in the marine bacterium Formosa algae strain KMM 3553T was cloned, and the protein (FFA2) was produced in Escherichia coli. Recombinant fucoidanase FFA2 was purified, and the biochemical properties of this enzyme were studied. The amino acid sequence of FFA2 showed 57% identity with known fucoidanase FcnA from Mariniflexile fucanivorans. The mass of the gene product FFA2 is 101.2 kDa (918 amino acid residues). Sequence analysis has revealed that fucoidanase FFA2 belongs to the GH107 (CAZy) family. Detailed substrate specificity was studied by using fucoidans from brown seaweeds as well as synthetic fucooligosaccharide with distinct structures. Fucoidanase FFA2 catalyzes the cleavage of (1→4)-α-glycosidic bonds in the fucoidan from Fucus evanescens within a structural fragment (→3)-α-l-Fucp2S-(1→4)-α-l-Fucp2S-(1→)n but not in a fragment (→3)-α-l-Fucp2S,4S-(1→4)-α-l-Fucp2S-(1→)n. Using synthetic di-, tetra- and octasaccharides built up of the alternative (1→4)- and (1→3)-linked α-l-Fucp2S units, the difference in substrate specificity and in the rate of enzymatic selectivity was investigated. Nonsulfated and persulfated synthetic oligosaccharides were not transformed by the enzyme. Therefore, FFA2 was specified as poly[(1→4)-α-l-fucoside-2-sulfate] glycanohydrolase. This enzyme could be used for the modification of natural fucoidans to obtain more regular and easier characterized derivatives useful for research and practical applications.

Fucoidanases

In recent years, the research of fucoidans has steadily increased. The interest in these substances is due to their various biological activities. Despite a wide range of biological activity and the lack of oral toxicity, fucoidans remain relatively unexploited as a source of medicines because of their heterogeneity. Enzymes that degrade polyanionic polysaccharides are widely used for establishing their structures and structure-activity relationships. Sometimes, to obtain preparations of polysaccharides with standard characteristics, for example, medicines and food supplements, enzymatic treatment can be also applied. Only a few sources of enzymes with fucoidanase activity have been described, and only a few studies regarding the isolation and characterization of fucoidanases have been performed. The data on the specificity of fucoidanases: the type of cleaved glycoside bond, the relation between catalytic activity and the degree of substrate sulfation are scarce. The review summarizes achievements in the research of fucoidanases, mechanisms of enzymatic degradation of fucoidans, as well as of structures of sulfated fucooligosaccharides obtained under the action of fucoidanases.

Purification and Characterization of a Fucoidanase (FNase S) from a Marine Bacterium Sphingomonas paucimobilis PF-1

The Search for enzyme activities that efficiently degrade marine polysaccharides is becoming an increasingly important area for both structural analysis and production of lower-molecular weight oligosaccharides. In this study, an endo-acting fucoidanase that degrades Miyeokgui fucoidan (MF), a sulfated galactofucan isolated from the sporophyll (called Miyeokgui in Korean) of Undaria pinnatifida, into smaller-sized galactofuco-oligosaccharides (1000-4000 Da) was purified from a marine bacterium, Sphingomonas paucimobilis PF-1, by ammonium sulfate precipitation, diethylaminoethyl (DEAE)-Sepharose column chromatography, and chromatofocusing. The specific activity of this enzyme was approximately 112-fold higher than that of the crude enzyme, and its molecular weight was approximately 130 kDa (FNase S), as determined by native gel electrophoresis and 130 (S1), 70 (S2) and 60 (S3) kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature of FNase S were pH 6.0-7.0 and 40-45 °C, respectively. FNase S activity was enhanced by Mn2+ and Na+ (115.7% and 131.2%), but it was inhibited by Ca2+, K+, Ba2+, Cu2+ (96%, 83.7%, 84.3%, and 89.3%, respectively), each at 1 mM. The Km, Vmax and Kcat values of FNase S on MF were 1.7 mM, 0.62 mg·min-1, and 0.38·S-1, respectively. This enzyme could be a valuable tool for the structural analysis of fucoidans and production of bioactive fuco-oligosaccharides.

Hydrolysis of fucoidan by fucoidanase isolated from the marine bacterium, Formosa algae

Intracellular fucoidanase was isolated from the marine bacterium, Formosa algae strain KMM 3553. The first appearance of fucoidan enzymatic hydrolysis products in a cell-free extract was detected after 4 h of bacterial growth, and maximal fucoidanase activity was observed after 12 h of growth. The fucoidanase displayed maximal activity in a wide range of pH values, from 6.5 to 9.1. The presence of Mg2+, Ca2+ and Ba2+ cations strongly activated the enzyme; however, Cu2+ and Zn2+ cations had inhibitory effects on the enzymatic activity. The enzymatic activity of fucoidanase was considerably reduced after prolonged (about 60 min) incubation of the enzyme solution at 45 °C. The fucoidanase catalyzed the hydrolysis of fucoidans from Fucus evanescens and Fucus vesiculosus, but not from Saccharina cichorioides. The fucoidanase also did not hydrolyze carrageenan. Desulfated fucoidan from F. evanescens was hydrolysed very weakly in contrast to deacetylated fucoidan, which was hydrolysed more actively compared to the native fucoidan from F. evanescens. Analysis of the structure of the enzymatic products showed that the marine bacteria, F. algae, synthesized an α-l-fucanase with an endo-type action that is specific for 1→4-bonds in a polysaccharide molecule built up of alternating three- and four-linked α-l-fucopyranose residues sulfated mainly at position 2.

Enzymatic preparation and structural determination of oligosaccharides derived from sea cucumber (Acaudina molpadioides) fucoidan

Sea cucumber fucoidan is a major bioactive component of sea cucumber. Sea cucumber is widely consumed in East Asian countries as healthy food. Employing the degrading enzyme from the marine bacterium strain Flavobacteriaceae CZ1127, sea cucumber (Acaudina molpadioides) fucoidan oligosaccharides were prepared by enzymatic hydrolysis. The oligosaccharide profile of the hydrolysate was determined by liquid chromatography coupled with mass spectrometry (LC-MS). With the assistance of LC-MS, four major oligosaccharides in the hydrolysate were purified. By using tandem mass spectrometry and nuclear magnetic resonance, delicate structures of the oligosaccharides were verified as α-l-Fucp-1→3-α-l-Fucp(2,4OSO3(2-))-1→3-α-l-Fucp, α-l-Fucp-1→3-α-l-Fucp(2,4OSO3(2-))-1→3-α-l-Fucp-1→3-α-l-Fucp, α-l-Fucp-1→3-α-l-Fucp(2,4OSO3(2-))-1→3-α-l-Fucp-1→3-α-l-Fucp-1→3-α-l-Fucp-1→3-α-l-Fucp(2,4OSO3(2-))-1→3-α-l-Fucp and α-l-Fucp-1→3-α-l-Fucp(2,4OSO3(2-))-1→3-α-l-Fucp-1→3-α-l-Fucp-1→3-α-l-Fucp-1→3-α-l-Fucp(2,4OSO3(2-))-1→3-α-l-Fucp-1→3-α-l-Fucp.

Algal fucoidan: structural and size-dependent bioactivities and their perspectives

Fucoidan is a complex-sulfated polysaccharide distributed in various marine organisms, and the brown algae are reported as the major producer. The fucoidan is important for their high bioactive properties, like antibacterial, anticoagulant, antiviral, anti-tumor, etc., and many more to be explored. There is a strong archival support for the bioactivity and promising properties of this molecule, which creates a hope for this molecule as future drug against thrombosis and some kind of cancers. Reports other than the above bioactive properties have also been a matter of interest for the design of signal or enzyme-arrested new class of drugs. In the past three decades, the research on isolation, molecular characterization, and screening of biological applications has significantly increased. One major issue associated with this molecule is the higher size and seasonal variation in their chemical composition; to resolve the issue and maintain its bioactivity, a prioritized and literal hydrolysis process is required to be developed. Here, in this mini-review, we have tried to summarize the algal fucoidan research and the bioactivities influenced by their molecular size.

Fucoidans and fucoidanases--focus on techniques for molecular structure elucidation and modification of marine polysaccharides

The research field of fucoidans (sulphated polysaccharides from algae) and fucoidanases was strongly developing in recent years. Several different fucoidans and a few fucoidan-degrading enzymes were isolated and characterised. A high potential is seen in the medical exploitation of the fucoidans and its degradation products. This review gives an overview about the research of the last 5 years concerning fucoidan characterisation and application as well as enzyme detection, characterisation and production.