Manufacturing polymethyl methacrylate nanofibers as a support for enzyme immobilization

Nanofibers have a great potential for enzyme immobilization application due to their large surface area to volume ratio besides their porous structure. In this work, we produce polymethyl methacrylate (PMMA) nanofibers via electrospinning method in dimethylformamide (DMF) as solvent. Thereafter, we employ a chemical method on final PMMA nanofiberous web to covalently immobilize acetylcholinesterase (AChE) enzyme on membrane surface. Morphology and tensile properties of nanofibers are studied as first steps of characterization to make sure of obtaining a properly stable membrane for enzyme carrying application. Thereafter, the stability and activity of immobilized enzymes as two main characteristic parameters are tested and reported for different applications such as biosensor manufacturing.     

Potential Cytotoxic Effects of Peptide Fractions from Dunaliella salina Protein Hydrolyzed by Gastric Proteases

Dunaliella salina is a halotolerant microalga with high protein content. Until now, there was no report on biological properties of peptides prepared by enzymatic digestion of D. salina proteins. Therefore, antimicrobial and antiproliferative effects of the abundant protein of D. salina were investigated. The extracted proteins were separated by fast protein liquid chromatography (FPLC), and protein hydrolysis was carried out with intestinal proteases such as trypsin and chymotrypsin. The antimicrobial and antiproliferative activities of the hydrolyzed peptides were examined on Escherichia coli, Staphylococcus aureus, and Helicobacter pylori, and colon cancer cell lines, respectively. The results demonstrated that 63 kDa protein and its derived peptides caused a decrease in bacteria growth, and <3 kDa peptide fraction significantly reduced SW480 cell viability. Therefore, the peptide fractions with antimicrobial and antiproliferative activities are worthy of further investigation as functional food ingredients for health benefits.