Abstract
As a low molecular weight alginate, alginate oligosaccharides (AOS) exhibit improved water solubility, better bioavailability, and comprehensive health benefits. In addition, their biocompatibility, biodegradability, non-toxicity, non-immunogenicity, and gelling capability make them an excellent biomaterial with a dual curative effect when applied in a drug delivery system. In this paper, a novel alginate lyase, Algpt, was cloned and characterized from a marine bacterium, Paenibacillus sp. LJ-23. The purified enzyme was composed of 387 amino acid residues, and had a molecular weight of 42.8 kDa. The optimal pH of Algpt was 7.0 and the optimal temperature was 45 °C. The analysis of the conserved domain and the prediction of the three-dimensional structure indicated that Algpt was a novel alginate lyase. The dominant degradation products of Algpt on alginate were AOS dimer to octamer, depending on the incubation time, which demonstrated that Algpt degraded alginate in an endolytic manner. In addition, Algpt was a salt-independent and thermo-tolerant alginate lyase. Its high stability and wide adaptability endow Algpt with great application potential for the efficient preparation of AOS with different sizes and AOS-based products.
Highlights
As a linear acidic polysaccharide, alginate is one of the main skeleton components in the matrix and cell walls of brown seaweed, and maintains a stable cell structure [1,2]
The alginate lyases from the polysaccharide lyase families (PLs)-6 and PL-31 families have a β-helix fold, while the PL-5, PL-15, and PL-17 members usually have (α/α)n toroid folds [3,19]
Based on further analysis of the multi-sequence alignment result, we discovered that Algpt contains the “R(H/S)GN” region, which is highly conserved in the PL-6 alginate lyases [17,30] (Figure 2a)
Summary
As a linear acidic polysaccharide, alginate is one of the main skeleton components in the matrix and cell walls of brown seaweed, and maintains a stable cell structure [1,2]. It consists of α-L-guluronic acid (G) and β-D-mannuronic acid (M), which are its constituent monomers. There are three types of constituent fragments in the long chain of alginate, including poly-Lguluronate (poly G), poly-D-mannuronate (poly M), and the heteropolyuronic blocks Its polymeric structure, poor solubility, and low bioavailability have greatly limited the biomedical application of alginate as a direct effector or functional component [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
