Scrutiny of Metal Ion Binding Sites in Different Alginate Lyases through In Silico Analysis.

Alginate lyases are epitomized as prospective therapeutic mediators for treating Pseudomonas aeruginosa infections, particularly in the cystic fibrosis airway through alginate degradation thereby improving the efficacy of anti-pseudomonal antibiotics. Investigation of metal-binding residues is significant for expounding the ion specificity of an enzyme and will provide a broad understanding of the potential roles of metal ions in enzyme function and stability. However, experimental analysis of metal ion-binding sites in proteins is time consuming and expensive. Concerning the clinical importance of this therapeutic enzyme, the present study was focused on the prediction and characterization of metal ion-binding sites of different alginate lyases reported in the literature through a computational approach using a Metal Ion-Binding Site Prediction and Docking Server. 3D structures of different alginate lyase from different organisms were retrieved, and these retrieved proteins were docked with twelve different metal ions such as Ca2+, Cu2+, Fe3+, Mg2+, Mn2+, Zn2+, Cd2+, Fe2+, Ni2+, Hg2+, Co2+, and Cu+. The binding affinity and interacting amino acids for alginate lyases produced by different microorganisms were compared and analysed. Further analysis on active site residues of reported alginate lyase and subsequent experiments will reveal the function of different metal ions in enhancing or inhibiting the catalysis of alginate lyase and will help in exploiting the enzyme as an efficient therapeutic agent as well as for industrial applications.

Bioactive and thermostable sulphated polysaccharide from Sargassum swartzii with drug delivery applications.

Sulphated Polysaccharides (SP) were extracted from a brown seaweed Sargassum swartzii by two extraction methods using hydrochloric acid and hot water. The sulphated polysaccharide yield using the hot water extraction method was found to be higher and hence used for further study. The extracted polysaccharide was characterized using UV, FT-IR, biochemical and thin layer chromatography analyses. Further, the purity of the extracted polysaccharide was ascertained by HPLC analysis. The sugars present in the sulphated polysaccharide were revealed by acid hydrolysis. The structure of the extracted SP was revealed as fucoidan using the NMR spectrum. Thermal stability of the sulphated polysaccharide was assessed using Thermogravimetric analysis and polymer was found to be stable up to 700 °C. Anti-oxidant and anti-inflammatory activities were evaluated using phosphomolybdenum and BSA assay, respectively. Cell proliferation analysis using MTT assay against normal cell lines revealed that the polysaccharide is biocompatible while with cancer cell lines, the compound exhibited potential anti-proliferative activity. Application of this sulphated polysaccharide as a carrier for drug delivery with rutin as a model drug was explored. The drug release kinetics was modeled and the stability of the rutin encapsulated SP nano formulation was studied.