scholarly journals Characterization of SdGA, a cold-adapted glucoamylase from Saccharophagus degradans

2021 ◽  
Author(s):  
Natael M. Wayllace ◽  
Nicolas Hedín ◽  
María V. Busi ◽  
Diego F. Gomez-Casati

ABSTRACTWe investigated the structural and functional properties of SdGA, a glucoamylase (GA) from Saccharophagus degradans, a marine bacterium which degrades different complex polysaccharides at high rate. SdGA is composed mainly by a N-terminal GH15_N domain linked to a C-terminal catalytic domain (CD) found in the GH15 family of glycosylhydrolases with an overall structure similar to other bacterial GAs. The protein was expressed in Escherichia coli cells, purified and its biochemical properties were investigated. Although SdGA has a maximum activity at 39°C and pH 6.0, it also shows high activity in a wide range, from low to mild temperatures, like cold-adapted enzymes. Furthermore, SdGA has a higher content of flexible residues and a larger CD due to various amino acid insertions compared to other thermostable GAs. We propose that this novel SdGA, is a cold-adapted enzyme that might be suitable for use in different industrial processes that require enzymes which act at low or medium temperatures.

2021 ◽  
Vol 12 ◽  
Author(s):  
Ning Ding ◽  
Boyang Zhao ◽  
Xiaofeng Ban ◽  
Caiming Li ◽  
B. V. Venkataram Prasad ◽  
...  

Marine extremophiles produce cold-adapted and/or salt-tolerant enzymes to survive in harsh conditions. These enzymes are naturally evolved with unique structural features that confer a high level of flexibility, solubility and substrate-binding ability compared to mesophilic and thermostable homologs. Here, we identified and characterized an amylase, SdG5A, from the marine bacterium Saccharophagus degradans 2-40T. We expressed the protein in Bacillus subtilis and found that the purified SdG5A enabled highly specific production of maltopentaose, an important health-promoting food and nutrition component. Notably, SdG5A exhibited outstanding cold adaptation and salt tolerance, retaining approximately 30 and 70% of its maximum activity at 4°C and in 3 M NaCl, respectively. It converted 68 and 83% of starch into maltooligosaccharides at 4 and 25°C, respectively, within 24 h, with 79% of the yield being the maltopentaose. By analyzing the structure of SdG5A, we found that the C-terminal carbohydrate-binding module (CBM) coupled with an extended linker, displayed a relatively high negative charge density and superior conformational flexibility compared to the whole protein and the catalytic domain. Consistent with our bioinformatics analysis, truncation of the linker-CBM region resulted in a significant loss in activities at low temperature and high salt concentration. This highlights the linker-CBM acting as the critical component for the protein to carry out its activity in biologically unfavorable condition. Together, our study indicated that these unique properties of SdG5A have great potential for both basic research and industrial applications in food, biology, and medical and pharmaceutical fields.


Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3915 ◽  
Author(s):  
Yue Yang ◽  
Zhou Zheng ◽  
Yifei Xiao ◽  
Jiaojiao Zhang ◽  
Yu Zhou ◽  
...  

Chitosanase plays an important role in the production of chitooligosaccharides (CHOS), which possess various biological activities. Herein, a glycoside hydrolase (GH) family 46 chitosanase-encoding gene, csnB, was cloned from marine bacterium Bacillus sp. BY01 and heterologously expressed in Escherichia coli. The recombinant chitosanase, CsnB, was optimally active at 35 °C and pH 5.0. It was also revealed to be a cold-adapted enzyme, maintaining 39.5% and 40.4% of its maximum activity at 0 and 10 °C, respectively. Meanwhile, CsnB showed wide pH-stability within the range of pH 3.0 to 7.0. Then, an improved reaction condition was built to enhance its thermostability with a final glycerol volume concentration of 20%. Moreover, CsnB was determined to be an endo-type chitosanase, yielding chitosan disaccharides and trisaccharides as the main products. Overall, CsnB provides a new choice for enzymatic CHOS production.


Marine Drugs ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. 596
Author(s):  
Lin-Lin Zhang ◽  
Xiao-Hua Jiang ◽  
Xin-Feng Xiao ◽  
Wen-Xiu Zhang ◽  
Yi-Qian Shi ◽  
...  

(1) Background: Chitooligosaccharides (COS) have numerous applications due to their excellent properties. Chitosan hydrolysis using chitosanases has been proposed as an advisable method for COS preparation. Although many chitosanases from various sources have been identified, the cold-adapted ones with high stability are still rather rare but required. (2) Methods: A novel chitosanase named CsnY from marine bacterium Renibacterium sp. Y82 was expressed in Escherichia coli, following sequence analysis. Then, the characterizations of recombinant CsnY purified through Ni–NTA affinity chromatography were conducted, including effects of pH and temperature, effects of metal ions and chemicals, and final product analysis. (3) Results: The GH46 family chitosanase CsnY possessed promising thermostability at broad temperature range (0–50 °C), and with optimal activity at 40 °C and pH 6.0, especially showing relatively high activity (over 80% of its maximum activity) at low temperatures (20–30 °C), which demonstrated the cold-adapted property. Common metal ions or chemicals had no obvious effect on CsnY except Mn2+ and Co2+. Finally, CsnY was determined to be an endo-type chitosanase generating chitodisaccharides and -trisaccharides as main products, whose total concentration reached 56.74 mM within 2 h against 2% (w/v) initial chitosan substrate. (4) Conclusions: The results suggest the cold-adapted CsnY with favorable stability has desirable potential for the industrial production of COS.


Marine Drugs ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 399
Author(s):  
Juanjuan Su ◽  
Xiaoyi Wang ◽  
Chengying Yin ◽  
Yujiao Li ◽  
Hao Wu ◽  
...  

Chondroitinases, catalyzing the degradation of chondroitin sulfate (CS) into oligosaccharides, not only play a crucial role in understanding the structure and function of CS, but also have been reported as a potential candidate drug for the treatment of high CS-related diseases. Here, a marine bacterium Vibrio hyugaensis LWW-1 was isolated, and its genome was sequenced and annotated. A chondroitinase, VhChlABC, was found to belong to the second subfamily of polysaccharide lyase (PL) family 8. VhChlABC was recombinant expressed and characterized. It could specifically degrade CS-A, CS-B, and CS-C, and reached the maximum activity at pH 7.0 and 40 °C in the presence of 0.25 M NaCl. VhChlABC showed high stability within 8 h under 37 °C and within 2 h under 40 °C. VhChlABC was stable in a wide range of pH (5.0~10.6) at 4 °C. Unlike most chondroitinases, VhChlABC showed high surfactant tolerance, which might provide a good tool for removing extracellular CS proteoglycans (CSPGs) of lung cancer under the stress of pulmonary surfactant. VhChlABC completely degraded CS to disaccharide by the exolytic mode. This research expanded the research and application system of chondroitinases.


2021 ◽  
Vol 12 ◽  
Author(s):  
Anke Chen ◽  
Dan Wang ◽  
Rui Ji ◽  
Jixi Li ◽  
Shaohua Gu ◽  
...  

Beta-glucosidase is an enzyme that catalyzes the hydrolysis of the glycosidic bonds of cellobiose, resulting in the production of glucose, which is an important step for the effective utilization of cellulose. In the present study, a thermostable β-glucosidase was isolated and purified from the Thermoprotei Thermofilum sp. ex4484_79 and subjected to enzymatic and structural characterization. The purified β-glucosidase (TsBGL) exhibited maximum activity at 90°C and pH 5.0 and displayed maximum specific activity of 139.2μmol/min/mgzne against p-nitrophenyl β-D-glucopyranoside (pNPGlc) and 24.3μmol/min/mgzen against cellobiose. Furthermore, TsBGL exhibited a relatively high thermostability, retaining 84 and 47% of its activity after incubation at 85°C for 1.5h and 90°C for 1.5h, respectively. The crystal structure of TsBGL was resolved at a resolution of 2.14Å, which revealed a classical (α/β)8-barrel catalytic domain. A structural comparison of TsBGL with other homologous proteins revealed that its catalytic sites included Glu210 and Glu414. We provide the molecular structure of TsBGL and the possibility of improving its characteristics for potential applications in industries.


2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Roisin O'Connor ◽  
Lorna M. Cryan ◽  
Kieran Wynne ◽  
Andreas de Stefani ◽  
Desmond Fitzgerald ◽  
...  

Proteomic approaches have proven powerful at identifying large numbers of proteins, but there are fewer reports of functional characterization of proteins in biological tissues. Here, we describe an experimental approach that fractionates proteins released from human platelets, linking bioassay activity to identity. We used consecutive orthogonal separation platforms to ensure sensitive detection: (a) ion-exchange of intact proteins, (b) SDS-PAGE separation of ion-exchange fractions and (c) HPLC separation of tryptic digests coupled to electrospray tandem mass spectrometry. Migration of THP-1 monocytes in response to complete or fractionated platelet releasate was assessed and located to just one of the forty-nine ion-exchange fractions. Over 300 proteins were identified in the releasate, with a wide range of annotated biophysical and biochemical properties, in particular platelet activation, adhesion, and wound healing. The presence of PEDF and involucrin, two proteins not previously reported in platelet releasate, was confirmed by western blotting. Proteins identified within the fraction with monocyte promigratory activity and not in other inactive fractions included vimentin, PEDF, and TIMP-1. We conclude that this analytical platform is effective for the characterization of complex bioactive samples.


2018 ◽  
Vol 56 (9) ◽  
pp. 656-664 ◽  
Author(s):  
Jingjing Sun ◽  
Wei Wang ◽  
Congyu Yao ◽  
Fangqun Dai ◽  
Xiangjie Zhu ◽  
...  

2008 ◽  
Vol 35 (6) ◽  
pp. 629-633 ◽  
Author(s):  
Yolanda González-García ◽  
Jesús Nungaray ◽  
Jesús Córdova ◽  
Orfil González-Reynoso ◽  
Martin Koller ◽  
...  

2021 ◽  
Vol 26 (2) ◽  
pp. 2511-2522
Author(s):  
ZHENGANG MA ◽  
◽  
JINFENG TONG ◽  
YAN WANG ◽  
ZEYANG ZHOU ◽  
...  

Chitinases are employed to the conversion of chitin and are produced by a wide range of bacteria. The objective of this study was to isolate chitinase-producing microorganisms with high chitinolytic activity. A thermostable alkaline chitinase producing isolate strain CQNU6-2 was obtained from soil samples and showed potential in biodegradation of shrimp shell wastes. The optimal culturing conditions of isolate CQNU6-2 is at 25°C and pH 7 for 24 h. The chitinase produced by strain CQNU6-2 exhibited maximum activity at pH 6.0 and 40°C and it could tolerate the treatment of high temperature (up to 80°C) and high pH (over 10). Taxonomic study, based on biochemical and morphological analysis and phylogenetic analysis of 16S rDNA, showed that strain CQNU6-2 was belongs to the genus Aeromonas sp. The isolate can effectively hydrolyze colloidal chitin with degradation rate of 100% and also can directly degrade the shrimp shells. Ammonium sulfate precipitation method can be used to preliminary purify the chitinase. In conclusion, strain CQNU6-2 had a promising potential for biodegradation of chitin under harsh pH or temperature conditions and could be employed to the comprehensive utilization of shrimp shell wastes.


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