scholarly journals The Characterization and Modification of a Novel Bifunctional and Robust Alginate Lyase Derived from Marinimicrobium sp. H1

Marine Drugs ◽  
2019 ◽  
Vol 17 (10) ◽  
pp. 545 ◽  
Author(s):  
Junjun Yan ◽  
Peng Chen ◽  
Yan Zeng ◽  
Yan Men ◽  
Shicheng Mu ◽  
...  

Alginase lyase is an important enzyme for the preparation of alginate oligosaccharides (AOS), that possess special biological activities and is widely used in various fields, such as medicine, food, and chemical industry. In this study, a novel bifunctional alginate lyase (AlgH) belonging to the PL7 family was screened and characterized. The AlgH exhibited the highest activity at 45 °C and pH 10.0, and was an alkaline enzyme that was stable at pH 6.0–10.0. The enzyme showed no significant dependence on metal ions, and exhibited unchanged activity at high concentration of NaCl. To determine the function of non-catalytic domains in the multi-domain enzyme, the recombinant AlgH-I containing only the catalysis domain and AlgH-II containing the catalysis domain and the carbohydrate binding module (CBM) domain were constructed and characterized. The results showed that the activity and thermostability of the reconstructed enzymes were significantly improved by deletion of the F5/8 type C domain. On the other hand, the substrate specificity and the mode of action of the reconstructed enzymes showed no change. Alginate could be completely degraded by the full-length and modified enzymes, and the main end-products were alginate disaccharide, trisaccharide, and tetrasaccharide. Due to the thermo and pH-stability, salt-tolerance, and bifunctionality, the modified alginate lyase was a robust enzyme which could be applied in industrial production of AOS.

2021 ◽  
Vol 12 ◽  
Author(s):  
Lu Liu ◽  
Zhipeng Wang ◽  
Zhihong Zheng ◽  
Ze Li ◽  
Xiaofeng Ji ◽  
...  

Alginate lyase possesses wide application prospects for the degradation of brown algae and preparation of alginate oligosaccharides, and its degradation products display a variety of biological activities. Although many enzymes of this type have been reported, alginate lyases with unique properties are still relatively rare. In the present work, an alginate lyase abbreviated as Alyw203 has been cloned from Vibrio sp. W2 and expressed in food-grade Yarrowia lipolytica. The Alyw203 gene consists of an open reading frame (ORF) of 1,566 bp containing 521 amino acids, of which the first 17 amino acids are considered signal peptides, corresponding to secretory features. The peak activity of the current enzyme appears at 45°C with a molecular weight of approximately 57.0 kDa. Interestingly, Alyw203 exhibits unique heat recovery performance, returning above 90% of its initial activity in the subsequent incubation for 20 min at 10°C, which is conducive to the recovery of current enzymes at low-temperature conditions. Meanwhile, the highest activity is obtained under alkaline conditions of pH 10.0, showing outstanding pH stability. Additionally, as an alginate lyase independent of NaCl and resistant to metal ions, Alyw203 is highly active in various ionic environments. Moreover, the hydrolyzates of present enzymes are mainly concentrated in the oligosaccharides of DP1–DP2, displaying perfect product specificity. The alkali suitability, heat recovery performance, and high oligosaccharide yield of Alyw203 make it a potential candidate for industrial production of the monosaccharide and disaccharide.


Author(s):  
Subaryono Subaryono ◽  
Rosmawaty Peranginangin ◽  
Maggy Thenawidjaja Suhartono ◽  
Fransiska Rungkat Zakaria

Alginate lyases are group of enzymes which catalyze depolymerization of alginate into oligosaccharides. Alginate lyase have been widely used in many applications such as in production of bioactive oligosaccharides, control of polysaccharide rheological properties, and polysaccharide structure analysis. The products of alginate lyase, polysaccharide structure analysis, alginate oligosaccharides (AOS) have many biological activities including act as prebiotics, immune modulator, anticoagulation, antioxidant, anticancer, growth promoting activities, promote production of antibiotics and ethanol. In relation to the importance of alginate lyases, their potential aplications and prospect in development of new bioactive products, we present review of the enzymes, sources, mechanism of activity and potential applications. This paper also discussed some new biological engineering in alginate lyase production.


2017 ◽  
Vol 20 (1) ◽  
pp. 63
Author(s):  
Subaryono Subaryono ◽  
Rosmawati Perangiangin ◽  
Maggy Thenawidjaja Suhartono ◽  
Fransiska Rungkat Zakaria

Alginate oligosaccharides (AOS) are oligosaccharides produced from depolimerization of the alginate polymer, and is reported to have various biological activities. The study aims is to determine the effect of AOS<br />production conditions and their effects on products and its activities as an immunomodulatory compound. Production of alginate oligosaccharides (AOS) enzymatically carried out with the help of alginate lyase enzyme produced from the bacterium Bacillus megaterium S245. Variation of incubation time is 2, 4, 6 and 8 hours at concentrations of alginate lyase enzyme addition of 25, 50, 75 and 100U. Treatment of enzyme concentration and the duration of incubation in the production of AOS produces a degree of polymerization (DP) 2-7. In vitro activity test showed AOS is have ability to induce cell proliferation of human lymphocytes.<br />This type of cell lymphocytes proliferation induced by AOS is a CD 8 cells or cytotoxic T cell and non cell CD4 / CD8. AOS production conditions with the addition of alginate lyase enzyme 50 U and incubation period 2 hours has produce AOS with the highest index of lymphocyte proliferation  117.6+3.6% or an increase of 43.24% compared to the native alginat polymer.<br /><br /><br />


Marine Drugs ◽  
2019 ◽  
Vol 18 (1) ◽  
pp. 25 ◽  
Author(s):  
Zhelun Zhang ◽  
Luyao Tang ◽  
Mengmeng Bao ◽  
Zhigang Liu ◽  
Wengong Yu ◽  
...  

Alginate lyases degrade alginate into oligosaccharides, of which the biological activities have vital roles in various fields. Some alginate lyases contain one or more carbohydrate-binding modules (CBMs), which assist the function of the catalytic modules. However, the precise function of CBMs in alginate lyases has yet to be fully elucidated. We have identified a new multi-domain alginate lyase, TsAly7B, in the marine bacterium Thalassomonas sp. LD5. This novel lyase contains an N-terminal CBM9, an internal CBM32, and a C-terminal polysaccharide lyase family 7 (PL7) catalytic module. To investigate the specific function of each of these CBMs, we expressed and characterized the full-length TsAly7B and three truncated mutants: TM1 (CBM32-PL7), TM2 (CBM9-PL7), and TM3 (PL7 catalytic module). CBM9 and CBM32 could enhance the degradation of alginate. Notably, the specific activity of TM2 was 7.6-fold higher than that of TM3. CBM32 enhanced the resistance of the catalytic module to high temperatures. In addition, a combination of CBM9 and CBM32 showed enhanced thermostability when incubated at 80 °C for 1 h. This is the first report that finds CBM9 can significantly improve the ability of enzyme degradation. Our findings provide new insight into the interrelationships of tandem CBMs and alginate lyases and other polysaccharide-degrading enzymes, which may inspire CBM fusion strategies.


Marine Drugs ◽  
2019 ◽  
Vol 18 (1) ◽  
pp. 32 ◽  
Author(s):  
Fu Hu ◽  
Benwei Zhu ◽  
Qian Li ◽  
Heng Yin ◽  
Yun Sun ◽  
...  

Alginate oligosaccharides with different degrees of polymerization (DPs) possess diverse physiological activities. Therefore, in recent years, increasing attention has been drawn to the use of enzymes for the preparation of alginate oligosaccharides for food and industrial applications. Previously, we identified and characterized a novel bifunctional alginate lyase Aly7A, which can specifically release trisaccharide from three different substrate types with a unique degradation pattern. Herein, we investigated its degradation pattern by modular truncation and molecular docking. The results suggested that Aly7A adopted a unique action mode towards different substrates with the substrate chain sliding into the binding pocket of the catalytic domain to position the next trisaccharide for cleavage. Deletion of the Aly7A carbohydrate binding module (CBM) domain resulted in a complex distribution of degradation products and no preference for trisaccharide formation, indicating that the CBM may act as a “controller” during the trisaccharide release process. This study further testifies CBM as a regulator of product distribution and provides new insights into well-defined generation of alginate oligosaccharides with associated CBMs.


Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 95 ◽  
Author(s):  
Yong-Hui Zhang ◽  
Yuan Shao ◽  
Chao Jiao ◽  
Qiu-Ming Yang ◽  
Hui-Fen Weng ◽  
...  

Alginate extracted from widely cultured brown seaweed can be hydrolyzed by alginate lyase to produce alginate oligosaccharides (AOS) with intriguing biological activities. Herein, a novel alginate lyase Aly1281 was cloned from marine bacterium Pseudoalteromonas carrageenovora ASY5 isolated from mangrove soil and found to belong to polysaccharide lyase family 7. Aly1281 exhibited maximum activity at pH 8.0 and 50 °C and have broad substrate specificity for polyguluronate and polymannuronate. Compared with other alginate lyases, Aly1281 exhibited high degradation specificity and mainly produced di-alginate oligosaccharides which displayed good antioxidant function to reduce ferric and scavenge radicals such as hydroxyl, ABTS+ and DPPH. Moreover, the catalytic activity and kinetic performance of Aly1281 were highly improved with the addition of salt, demonstrating a salt-activation property. A putative conformational structural feature of Aly1281 was found by MD simulation analysis for understanding the salt-activation effect.


Marine Drugs ◽  
2020 ◽  
Vol 18 (8) ◽  
pp. 388
Author(s):  
Hai-Xiang Zhou ◽  
Shan-Shan Xu ◽  
Xue-Jing Yin ◽  
Feng-Long Wang ◽  
Yang Li

Alginate oligosaccharides produced by enzymatic degradation show versatile physiological functions and biological activities. In this study, a new alginate lyase encoding gene alyS02 from Flavobacterium sp. S02 was recombinantly expressed at a high level in Yarrowia lipolytica, with the highest extracellular activity in the supernatant reaching 36.8 ± 2.1 U/mL. AlyS02 was classified in the polysaccharide lyase (PL) family 7. The optimal reaction temperature and pH of this enzyme were 30 °C and 7.6, respectively, indicating that AlyS02 is a cold-adapted enzyme. Interestingly, AlyS02 contained more than 90% enzyme activity at 25 °C, higher than other cold-adapted enzymes. Moreover, AlyS02 is a bifunctional alginate lyase that degrades both polyG and polyM, producing di- and trisaccharides from alginate. These findings suggest that AlyS02 would be a potent tool for the industrial applications.


Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 295 ◽  
Author(s):  
Jingjing Zhuang ◽  
Keke Zhang ◽  
Xiaohua Liu ◽  
Weizhi Liu ◽  
Qianqian Lyu ◽  
...  

Alginate lyases are enzymes that degrade alginate into oligosaccharides which possess a variety of biological activities. Discovering and characterizing novel alginate lyases has great significance for industrial and medical applications. In this study, we reported a novel alginate lyase, AlyA-OU02, derived from the marine Vibrio splendidus OU02. The BLASTP searches showed that AlyA-OU02 belonged to polysaccharide lyase family 7 (PL7) and contained two consecutive PL7 domains, which was rare among the alginate lyases in PL7 family. Both the two domains, AlyAa and AlyAb, had lyase activities, while AlyAa exhibited polyM preference, and AlyAb was polyG-preferred. In addition, the enzyme activity of AlyAa was much higher than AlyAb at 25 °C. The full-length enzyme of AlyA-OU02 showed polyM preference, which was the same as AlyAa. AlyAa degraded alginate into di-, tri-, and tetra-alginate oligosaccharides, while AlyAb degraded alginate into tri-, tetra-, and penta-alginate oligosaccharides. The degraded products of AlyA-OU02 were similar to AlyAa. Our work provided a potential candidate in the application of alginate oligosaccharide production and the characterization of the two domains might provide insights into the use of alginate of this organism.


2021 ◽  
pp. jclinpath-2020-206927
Author(s):  
Maryam Ahmed Al Barashdi ◽  
Ahlam Ali ◽  
Mary Frances McMullin ◽  
Ken Mills

The leucocyte common antigen, protein tyrosine phosphatase receptor type C (PTPRC), also known as CD45, is a transmembrane glycoprotein, expressed on almost all haematopoietic cells except for mature erythrocytes, and is an essential regulator of T and B cell antigen receptor-mediated activation. Disruption of the equilibrium between protein tyrosine kinase and phosphatase activity (from CD45 and others) can result in immunodeficiency, autoimmunity, or malignancy. CD45 is normally present on the cell surface, therefore it works upstream of a large signalling network which differs between cell types, and thus the effects of CD45 on these cells are also different. However, it is becoming clear that CD45 plays an essential role in the innate immune system and this is likely to be a key area for future research. In this review of PTPRC (CD45), its structure and biological activities as well as abnormal expression of CD45 in leukaemia and lymphoma will be discussed.


2019 ◽  
Vol 476 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Antonio Eufrásio Vieira Neto ◽  
Felipe Domingos de Sousa ◽  
Humberto D'Muniz Pereira ◽  
Frederico Bruno Mendes Batista Moreno ◽  
Marcos Roberto Lourenzoni ◽  
...  

Abstract Frutalin (FTL) is a multiple-binding lectin belonging to the jacalin-related lectin (JRL) family and derived from Artocarpus incisa (breadfruit) seeds. This lectin specifically recognizes and binds α-d-galactose. FTL has been successfully used in immunobiological research for the recognition of cancer-associated oligosaccharides. However, the molecular bases by which FTL promotes these specific activities remain poorly understood. Here, we report the whole 3D structure of FTL for the first time, as determined by X-ray crystallography. The obtained crystals diffracted to 1.81 Å (Apo-frutalin) and 1.65 Å (frutalin–d-Gal complex) of resolution. The lectin exhibits post-translational cleavage yielding an α- (133 amino acids) and β-chain (20 amino acids), presenting a homotetramer when in solution, with a typical JRL β-prism. The β-prism was composed of three 4-stranded β-sheets forming three antiparallel Greek key motifs. The carbohydrate-binding site (CBS) involved the N-terminus of the α-chain and was formed by four key residues: Gly25, Tyr146, Trp147 and Asp149. Together, these results were used in molecular dynamics simulations in aqueous solutions to shed light on the molecular basis of FTL-ligand binding. The simulations suggest that Thr-Ser-Ser-Asn (TSSN) peptide excision reduces the rigidity of the FTL CBS, increasing the number of interactions with ligands and resulting in multiple-binding sites and anomeric recognition of α-d-galactose sugar moieties. Our findings provide a new perspective to further elucidate the versatility of FTL in many biological activities.


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